Merge remote app attribution branch
Resolve the RFC and implementation to defer OpenRouter-specific attribution headers and keep mandatory attribution to User-Agent only.
This commit is contained in:
Tianyi Cui
@@ -17,7 +17,7 @@ Reject the pervasive `DeepReadonly<T>` type flip. Instead:
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1. **Always-on:** `deriveMessages()` deep-clones the content it emits (one `structuredClone` per derived message). In-flight mutation of a request can no longer reach the log — this is the real fix, and it costs nothing meaningful next to a model call.
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2. **Dev-mode:** a new `dsh-invariants` plugin (pure listeners, off in production, on in tests and demos) asserts the event contract and `Object.freeze`s logged event data so any *other* code that mutates a logged event throws instead of corrupting silently. Seeded sessions are frozen and checked on `session/created` (the constructor copies the seed without emitting `session/event`).
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The invariants encode the *real* contract, not an idealized one: a `tool/call` may have no `tool/result` (a thrown `tools/execute` waterfall ends the step), and both `idle→disposed` and `running→disposed` are legal.
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The invariants encode the *real* contract, not an idealized one: a `tool/call` may have no `tool/result` (a thrown tool-execution pipeline step ends the turn), and both `idle→disposed` and `running→disposed` are legal.
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`DeepReadonly` was rejected because it is compile-time only (a plugin casts straight through it), high type-noise across every log/message consumer and adapter, and would force readonly types through code where mutation is the sanctioned API. The clone draws the mutable/immutable boundary exactly at "logged vs in-flight" without any of that noise.
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@@ -12,7 +12,7 @@ The product principle (see the 微内核Harness实现思路 design doc) is "ever
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Pure Cordis event taxonomy. The loop's extension seams are typed events with deliberate dispatch modes:
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- **waterfall** (around-middleware) where plugins mutate or veto: `agent/request`, `agent/step-result`, `agent/turn-continuation`, `tools/execute`, `llm/stream`, `llm/generate`, `system-prompt/assemble`.
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- **waterfall** (around-middleware) where plugins mutate or veto: `agent/prompt-submit`, `agent/request`, `agent/step-result`, `agent/turn-continuation`, `tools/pre-execute`, `tools/post-execute`, `llm/stream`, `system-prompt/assemble`.
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- **emit** (sync fire-and-forget) for notifications: turn/step boundaries, stream chunks, lifecycle, errors.
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- **parallel** (awaited) for the one durability checkpoint: `session/flush`.
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@@ -20,7 +20,7 @@ The event vocabulary lives in interface packages (dsh-agent declares the agent/*
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## Consequences
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- Every MVP feature maps to a listener (the "plugin sanity checklist" in docs/architecture.md is the proof obligation, kept current).
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- Every MVP feature maps to a listener (the [feature → mechanism map](../../../cookbook/extension-cookbook.md#the-feature--mechanism-map) is the proof obligation, kept current).
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- HMR and disposal come free: listeners and registrations are Cordis effects.
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- Waterfall semantics (call `next()` or short-circuit) are non-obvious and must be taught — documented in AGENTS.md and covered by composition tests.
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- The loop must be defensive: plugin exceptions are contained at turn level, steering from any seam is never stranded (regression-tested).
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@@ -20,7 +20,7 @@ A swappable capability is **three packages**:
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Implementation and consumer then evolve independently: a sandboxed executor replaces `dsh-bash-local` without touching a tool schema.
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Alternatives considered: **one combined package** — rejected because it recouples the three rates of change the split exists to separate (the whole point). **`@cordisjs/plugin-capability`** — a different axis entirely: it is a permission/capability-*security* service (named permissions with inheritance, tested against a session via `ctx.capability.test`), a candidate for the deferred permissions/sandbox work on the `tools/execute` veto seam, NOT a mechanism for swapping implementations. Confusing the two ("capability") is the trap this RFC names.
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Alternatives considered: **one combined package** — rejected because it recouples the three rates of change the split exists to separate (the whole point). **`@cordisjs/plugin-capability`** — a different axis entirely: it is a permission/capability-*security* service (named permissions with inheritance, tested against a session via `ctx.capability.test`), a candidate for the deferred permissions/sandbox work on the `tools/pre-execute` deny/ask seam, NOT a mechanism for swapping implementations. Confusing the two ("capability") is the trap this RFC names.
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The split is not mandatory when the parts are genuinely one concern: the LLM seam folds interface + consumer into `dsh-llm` (the consumer is the loop itself, not a swappable schema surface) with adapters as the implementation packages. Don't split preemptively — a capability with one conceivable implementation and one consumer stays one package until a second appears.
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@@ -16,7 +16,7 @@ The [event-sourced model](2026-06-11-event-sourced-sessions.md) makes the append
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Persistence is an abstract **capability seam** ([capability seams](2026-06-13-capability-seams.md), the `dsh-bash` template), not loop or core logic:
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1. **Interface** (`dsh-session-persistence`, `ctx.sessionPersistence`) — an abstract `SessionPersistence` service: `create`/`append`/`load`/`list`/`has`/`delete`. Its persisted unit IS the existing `SessionEvent` (`{ type, seq, time, data }`), reused verbatim — no conversion type.
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1. **Interface** (`dsh-session-persistence`, `ctx.sessionPersistence`) — an abstract `SessionPersistence` service: `create`/`append`/`load`/`list`. Its persisted unit IS the existing `SessionEvent` (`{ type, seq, time, data }`), reused verbatim — no conversion type.
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2. **Implementation** (`dsh-session-persistence-jsonl`) — an append-only JSONL log per session (a `SessionHeader` line then one `SessionEvent` per line, verbatim **including `assistant/chunk`**).
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Key choices recorded here because they are durable, contested, and surprising:
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@@ -27,7 +27,7 @@ Key choices recorded here because they are durable, contested, and surprising:
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- **Metadata is out-of-log.** Format version, cwd, and lineage are storage concerns, not replayable conversation state, so they live in a `SessionHeader` owned by `dsh-session` and attached to a `Session` via a new readonly `session.header` — never in `SessionEventMap`, never reaching `deriveMessages()`. The alternative (a merge-extensible `session/meta` event as log line 0) was rejected: an in-log event would ride along with a seeded/forked session for free, but metadata is not replayable state, so the explicit out-of-log header seam is the cleaner cost. (The header was originally split into an immutable `SessionHeader` plus a mutable `SessionSummary` whose union was `SessionMeta`; the mutable summary was later removed as dead state — see [Drop the mutable session summary](../simplification/2026-06-19-drop-mutable-session-summary.md).)
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- **Resume is an async factory, not a change to synchronous create.** `ctx.agents.resume({ resumeSessionId })` awaits `ctx.sessionPersistence.load`, recreates the live session with the loaded events (so `lastTurnNumber`/`deriveMessages` continue), and starts a fresh agent on the resumed id (NOT `${agentId}-session`). The agent-loop does NOT hard-inject `sessionPersistence` (that would pend non-persistent demos forever); `resume` rejects with a clear error when it is absent.
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Format versioning: the header carries a `version`; `load` rejects an unknown version (no v1 migration). Stated honestly: append-only + flush is robust to partial trailing writes (tolerated on load) but not to fsync-less power loss mid-line; a DB/WAL backend is the stronger option later.
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Format versioning: the header carries a `version`; `load` rejects any non-current version (no migration — the pre-release session format is pinned at `SESSION_FORMAT_VERSION = 0` and absorbs shape churn, per the AGENTS.md pre-release stance). Stated honestly: append-only + flush is robust to partial trailing writes (tolerated on load) but not to fsync-less power loss mid-line; a DB/WAL backend is the stronger option later.
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## Consequences
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@@ -37,4 +37,4 @@ Costs: `agent.inject()` while idle now writes three log lines instead of one, an
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The rule is intentionally producer-enforced and dev-checked rather than reader-tolerated: a future backend (SQLite/WAL) inherits the same clean boundary for free, and a plugin that records an event outside a turn fails loudly in dev instead of silently losing data on the next reload.
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The invariant also constrains where the loop may record an `error` event. A failure detected while a turn is open is appended INSIDE the turn (before `turn/end`); but a failure that surfaces once the turn is already closed — a rejecting `session/flush` (which runs as the post-`turn/end` durability checkpoint) or a throwing `agent/turn-end` listener (after `closeTurn` already appended `turn/end`) — has no in-turn position left. Appending an `error` there would land it past the last `turn/end`, exactly the crash-tail position a backend discards. So those post-turn failures are reported via the `agent/error` event and the logger only, never as a `SessionEvent`; the turn stays balanced and persistence keeps its buffered events for the next checkpoint. If durable operational diagnostics are ever needed, they belong on a separate telemetry channel, not the replayable session log.
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The invariant also constrains where the loop may record an `error` event. A failure detected while a turn is open is appended INSIDE the turn (before `turn/end`); but a failure that surfaces once the turn is already closed — a rejecting `session/flush`, which runs as the post-`turn/end` durability checkpoint — has no in-turn position left. Appending an `error` there would land it past the last `turn/end`, exactly the crash-tail position a backend discards. So that post-turn failure is reported via the `agent/error` event and the logger only, never as a `SessionEvent`; the turn stays balanced and persistence keeps its buffered events for the next checkpoint. If durable operational diagnostics are ever needed, they belong on a separate telemetry channel, not the replayable session log.
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@@ -0,0 +1,184 @@
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# RFC: Filesystem capability seam — ctx.fs, local backend, and model-facing filesystem tools
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Status: implemented
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## Problem
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The harness has a concrete `bash` capability seam (`dsh-bash` / `dsh-bash-local` / `dsh-tool-bash`), but filesystem operations are about to be added as model-facing tools without an equivalent seam. If `read`, `write`, and `edit` directly use `node:fs`, the model-facing tool package will own filesystem execution policy, local path resolution, atomic write behavior, text decoding, symlink behavior, and edit semantics all at once.
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That couples three concerns that change independently:
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1. The filesystem contract: what operations plugins can ask for.
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2. The backend: local disk now, sandboxed/remote/project-scoped filesystem later.
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3. The consumer surface: model-facing `read` / `write` / `edit` schemas and result formatting.
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Without a `ctx.fs` interface, swapping local filesystem access for a sandboxed or remote backend would churn the tool schemas, demos, and prompt guidance even when the model-facing contract should stay stable. It also makes permission/sandbox boundaries harder to reason about: a `cwd` option can look like a sandbox even though it is only a base path unless an explicit backend or `tools/execute` policy enforces containment.
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We need the filesystem tools to land in the same capability-seam shape as bash before they become a public package surface.
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## Proposal
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Introduce filesystem access as a first-class capability seam following [the capability-seam RFC](../../implemented/architecture/2026-06-13-capability-seams.md):
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1. `@deepseek-ai/dsh-fs` (`packages/fs/fs`) owns the abstract `ctx.fs` service, the filesystem vocabulary types, and the `fs/*` policy event vocabulary.
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2. `@deepseek-ai/dsh-fs-local` (`packages/fs/fs-local`) provides the first implementation, backed by the local filesystem.
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3. `@deepseek-ai/dsh-tool-fs` (`packages/fs/tool-fs`) provides the model-facing `read`, `write`, and `edit` tools over `ctx.fs`, and is the executor that dispatches the `fs/*` events.
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The consumer package depends only on the interface package, never on `dsh-fs-local`. A deployment that wants a different backend loads a different provider for `ctx.fs` without changing the tool schemas or model-facing prompt guidance.
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The read-before-write/edit and observed-state policy is a fourth package, `@deepseek-ai/dsh-fs-policy` (`packages/fs/fs-policy`), contributed through the `fs/*` event gate rather than living on `ctx.fs`. This RFC established the three-package seam; the split of policy off the provider base class is decided by [the split-fs-seam RFC](../simplification/2026-06-26-fsspec-style-fs-seam.md), and its realization as an event-gate plugin (not a method service) by [the event-gate RFC](2026-06-26-file-context-as-event-gate.md). This document is updated to describe that landed four-package shape.
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The first backend is deliberately local-only: `dsh-fs-local` implements `ctx.fs` against the host filesystem. Future sibling backends can provide sandboxed, remote, virtual, or project-scoped filesystems behind the same interface.
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The first consumer is deliberately text-file-only: `dsh-tool-fs` exposes model-facing `read`, `write`, and `edit` tools for UTF-8 text files. Future consumers can add directory listing, search/glob, binary-safe operations, file watching, or higher-level project operations without changing the local backend package, as long as the needed capability exists on `ctx.fs`. Direct directory listing was later added by [Add direct directory listing to the filesystem seam](2026-07-03-filesystem-directory-listing-seam.md).
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Filesystem permissions and sandboxing are not implied by this split. The local backend resolves relative paths from its configured base directory, but containment policy is a separate decision: either a stricter `ctx.fs` implementation enforces it, or a permission/sandbox plugin wraps `tools/execute` and vetoes calls before they reach the consumer.
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Read-before-write/edit and observed-state are policy, contributed by the `dsh-fs-policy` plugin through the `fs/*` event gate — NOT stored on `ctx.fs`. The provider seam offers an optional version guard on its mutations (`writeText`/`editText` take an optional expectation); the policy plugin decides that guard by listening on `fs/write-intent`/`fs/edit-intent` and records observed versions on `fs/observed`. The executor (`dsh-tool-fs`) passes the current tool execution context as the opaque event actor; the policy plugin derives the observed-state owner from it, normally `exec.agent.session`. `dsh-fs` treats the actor as opaque and never reads it; `dsh-tool-fs` never reaches into the policy plugin. Authorization is version freshness: any read records the file's version, and a later write/edit is authorized as long as the file is unchanged. (This RFC first placed the observed-state store on `ctx.fs`; the split to `dsh-fs-policy` on the `fs/*` event gate is decided by [the split-fs-seam](../simplification/2026-06-26-fsspec-style-fs-seam.md) and [event-gate](2026-06-26-file-context-as-event-gate.md) RFCs.)
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## Package topology
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The filesystem seam uses the same dependency direction as the bash trio:
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```text
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@deepseek-ai/dsh-tool-fs --depends on--> @deepseek-ai/dsh-fs <--depends on-- @deepseek-ai/dsh-fs-local
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consumer interface implementation
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```
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`@deepseek-ai/dsh-fs` depends only on `cordis` plus the repo-wide `HarnessError` base from `@deepseek-ai/dsh-llm`. It declares the `ctx.fs` key, the abstract `FileSystem` service, the vocabulary types shared by backends and consumers, the filesystem error vocabulary, and the `fs/*` policy event vocabulary. It carries no observed-state store and no owner-derivation shape; the events pass an opaque `object` actor that the provider never reads, and the `dsh-fs-policy` plugin owns the owner-derivation shape and the observed-state store on top of those events.
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`@deepseek-ai/dsh-fs-local` depends on `@deepseek-ai/dsh-fs` and `cordis`. It subclasses `FileSystem`, registers itself as `ctx.fs`, owns local-backend configuration such as the base directory, and contains all direct `node:fs` / `node:path` access. It holds no observed-state store — freshness is a version token the backend mints and the policy plugin records.
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`@deepseek-ai/dsh-tool-fs` depends on `@deepseek-ai/dsh-fs`, `@deepseek-ai/dsh-tools`, `@deepseek-ai/dsh-system-prompt`, and `cordis`. It registers model-facing tools and prompt sections. It must not import `node:fs`, `node:path`, or `@deepseek-ai/dsh-fs-local`; filesystem execution always goes through `ctx.fs`. If the implementation needs concrete agent or session helper types, those dependencies belong in `tool-fs`; they must not leak back into `dsh-fs`.
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The root `tool-fs` plugin registers the full filesystem tool suite (`read`, `write`, and `edit`) by composing the per-tool registration helpers. It injects `fs` and never imports an implementation package.
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## `ctx.fs` contract
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`@deepseek-ai/dsh-fs` owns a semantic filesystem service. It is higher-level than `readFile` / `writeFile` so `tool-fs` does not reimplement path resolution, versioning, text decoding, binary rejection, pagination, atomic replacement, symlink behavior, or literal edit semantics.
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The exact TypeScript signatures are implementation details for the PR, but the interface must cover four semantic operations:
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- Resolve a model/plugin-supplied path into a backend-defined target.
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- Stat target metadata without reading file contents.
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- Read a bounded UTF-8 text page from a target.
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- Create or replace a UTF-8 text file.
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- Edit an existing UTF-8 text file by literal replacement.
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The provider seam also carries the freshness hooks that policy builds on — but the observed-state store and owner derivation live in the `dsh-fs-policy` plugin, not on `ctx.fs`:
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- The backend mints an opaque `version` token per target (in `stat` and in every read/mutation outcome).
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- `writeText`/`editText` take an OPTIONAL version expectation: omit it for an unconditional bare-provider mutation, or supply it to guard the mutation inside the backend's atomic critical section.
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- The `dsh-fs-policy` plugin decides that expectation on `fs/write-intent`/`fs/edit-intent` and records observed versions on `fs/observed`, keyed by an owner it derives from the opaque event actor (normally `exec.agent.session`).
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Authorization is version freshness, not a full/partial view distinction: any read records the target's version, and a later write/edit is authorized as long as the file is still at that version — so a windowed read of lines 100-150 authorizes an edit of line 120. The observed-state store is a `WeakMap<owner, Map<targetKey, version>>` inside `dsh-fs-policy`; `dsh-fs` holds none of it and treats the actor as opaque. (This RFC first modeled a `FileState` cache with `full`/`partial` views on `ctx.fs`; the split-fs-seam and event-gate RFCs replaced that with the freshness-based policy plugin described here.)
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Path resolution should be explicit and allowed to be async. Local resolution may only normalize a path, but sandboxed/remote/project-scoped backends may need I/O to resolve a user-supplied path into a stable target identity.
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Resolved targets must expose at least three concepts:
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- The original input path, for diagnostics.
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- An opaque `targetKey`, used for stale guards and file-state lookup. The local backend might use a realpath-like key; a remote backend might use a workspace URI or file id. Consumers must not parse or assume this is a local absolute path.
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- A `displayPath`, used for model/UI-facing output. It may be a local absolute path, workspace-relative path, or remote URI depending on the backend.
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Read and mutation results must include an opaque file `version`. A local backend can use mtime/size or a hash-like token; a remote backend can use a revision id. `ctx.fs` records versions in its file-state store for stale checks; consumers may display related metadata but must not interpret the version token.
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The provider hands back decoded text: `readText` returns a whole regular text file, `streamText` streams the same text semantics for large files. Both own regular-file checks, bounded line/output handling is NOT theirs — line windowing, numbered-line rendering, and total-line accounting live in the executor (`dsh-tool-fs`), which reads through `ctx.fs` and renders the model-facing window. The provider owns UTF-8 decoding and binary/NUL rejection; it does not know about line windows or views.
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Observed-state recording is not on `ctx.fs`: after a successful read the executor emits `fs/observed`, and the `dsh-fs-policy` plugin records `{ version }` for the deriving owner. There is no `full`/`partial` view — a read at any window records the version, and freshness (not view completeness) authorizes a later write/edit.
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Full-file writes create or replace UTF-8 text files. Backends may create parent directories when that behavior is supported and documented. Existing non-regular targets are rejected. `writeText` takes an optional expectation: `createIfAbsent` creates a missing target and rejects an existing one with `FS_NOT_OBSERVED` (the path the policy uses for an unobserved owner); `replaceIfVersion` replaces only when the target exists at the observed version, else `FS_STALE_VERSION`; omitting the expectation is the unconditional bare-provider create-or-overwrite. The policy plugin chooses which expectation to supply from the owner's observed state.
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Literal edit is a provider primitive (`editText`), not composed in `tool-fs` from a read plus write. Literal matching, duplicate-match rejection, CRLF preservation, binary rejection, optional stale-version checking, and atomic read-modify-write must stay together inside the backend's mutation critical section. `editText` takes the same optional version expectation; the stale check runs before literal matching so an edit against an old read reports `FS_STALE_VERSION`. A remote backend may implement edit as a native compare-and-edit operation; the consumer should not force local-style composition.
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The policy plugin, not `ctx.fs`, gates on prior observation: an `edit` requires a prior observation by the owner (else `FS_NOT_OBSERVED`), and the recorded version is passed to `editText` as the CAS basis. With the policy plugin absent, `ctx.fs` alone is a complete unconstrained seam (unconditional write/edit); the tool is never method-coupled to the policy.
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||||
Filesystem contract failures are thrown as `FsError extends HarnessError`, and the tool registry converts them into `isError` tool results with structured `{ name, code }` metadata. `dsh-fs` owns this vocabulary rather than each tool inventing messages. The codes are `FS_NOT_FOUND`, `FS_NOT_TEXT`, `FS_STALE_VERSION`, `FS_NOT_OBSERVED`, `FS_NOT_REGULAR_FILE`, `FS_AMBIGUOUS_EDIT`, `FS_EDIT_NOT_FOUND`, and `FS_ABORTED`. (An earlier draft included `FS_PARTIAL_OBSERVATION`; freshness-based authorization has no partial/full distinction, so it was dropped. Directory-listing-specific codes were added later by [Add direct directory listing to the filesystem seam](2026-07-03-filesystem-directory-listing-seam.md).)
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||||
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||||
## Tool consumer behavior
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||||
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||||
`@deepseek-ai/dsh-tool-fs` is the model-facing consumer. It owns tool names, JSON schemas, argument validation at the model boundary, prompt sections, and result formatting. It does not own filesystem execution.
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||||
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||||
The first tool suite contains:
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||||
|
||||
- `read`: inspect a UTF-8 text file and return line-numbered content with pagination guidance.
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||||
- `write`: create or fully replace a UTF-8 text file.
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||||
- `edit`: update an existing UTF-8 text file by replacing literal text, requiring a unique match by default and allowing an explicit replace-all mode.
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||||
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||||
Each tool follows the same execution shape:
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||||
|
||||
1. Validate and normalize model arguments.
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||||
2. Call the appropriate `ctx.fs` operation.
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||||
3. Format the result as `ContentBlock[]` for the model.
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||||
4. Let thrown backend/tool errors flow through `ToolRegistry.execute()`, which converts them into `isError` tool results.
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||||
|
||||
The package registers prompt guidance through `ctx.systemPrompt.section(...)` and registers schemas through `ctx.tools.register(...)`. Tool schemas still flow into the normal prompt assembly path via `SystemPrompt.assemble()` and `ToolRegistry.schemas()`; no agent-loop changes are required.
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||||
|
||||
The tool package must keep model-facing contracts stable when backends change. A local backend and a remote backend may resolve paths differently internally, but the `read` / `write` / `edit` schemas should not change solely because the backend changes.
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||||
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||||
The default deployment requires a prior `read` before updating an existing file with `write` or `edit`. `tool-fs` does not implement this by checking whether a tool named `read` ran: it dispatches the `fs/write-intent`/`fs/edit-intent` events (passing the execution context as the opaque actor), and the `dsh-fs-policy` plugin derives the owner, gates on prior observation, and supplies the version expectation. Any windowed read authorizes a later write/edit as long as the file is unchanged. Creating a new file with `write` does not require prior observation.
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||||
|
||||
The root plugin registers the full suite by composing the per-tool registration helpers. It injects `fs`, `tools`, and `systemPrompt`.
|
||||
|
||||
## Migration plan
|
||||
|
||||
This RFC starts from `origin/master`, where no filesystem tool package exists yet. The landed implementation adds the new three-package topology directly:
|
||||
|
||||
1. Add `packages/fs/fs` with the `ctx.fs` abstract service and vocabulary types.
|
||||
2. Add `packages/fs/fs-local` with the local backend implementation and backend-level tests.
|
||||
3. Add `packages/fs/tool-fs` with the model-facing `read`, `write`, and `edit` tools over `ctx.fs`.
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||||
4. Update `docs/architecture.md`, `packages/README.md`, package READMEs, build/typecheck config, and aggregate maintenance scripts such as `scripts/publint-all.ts`.
|
||||
|
||||
This RFC's first landing kept the observed-state store behind `ctx.fs`. The split-fs-seam and event-gate RFCs then moved it into the standalone `@deepseek-ai/dsh-fs-policy` plugin on the `fs/*` event gate, which is the shipped shape; a deployment loading `dsh-tool-fs` also loads `dsh-fs-policy` to get read-before-write/edit.
|
||||
|
||||
Example leaf configs stay bash-only in this landing. Wiring `examples/coding-agent` or `examples/acp-agent` to `dsh-fs-local` + `dsh-tool-fs` changes the model prompt, visible tool schemas, and ACP snapshot transcript, so it should land as a follow-up UX/example change with prompt and snapshot updates in the same PR.
|
||||
|
||||
If this work is split into multiple PRs, they should follow the seam order:
|
||||
|
||||
1. Interface PR: `dsh-fs` only, with service registration and contract tests.
|
||||
2. Implementation PR: `dsh-fs-local`, with real filesystem behavior tests.
|
||||
3. Consumer PR: `dsh-tool-fs`, docs, and integration tests; example wiring follows in a separate prompt/snapshot PR.
|
||||
|
||||
The earlier combined package name `@deepseek-ai/dsh-fs-tools` should not become part of the new public surface.
|
||||
|
||||
## Tests
|
||||
|
||||
Tests should follow the package boundary, not only the user-visible tools.
|
||||
|
||||
`dsh-fs` tests cover the service seam itself: a provider registers `ctx.fs`, duplicate providers follow Cordis service behavior, disposal removes the service, and any shared contract helpers or type-level utilities behave as documented.
|
||||
|
||||
`dsh-fs-local` tests cover real filesystem behavior through the `ctx.fs` interface, not through model tools. They should include path resolution, absolute paths, `..` segments, symlinks inside and outside the configured base directory, reading small and large text files, streaming, binary-file rejection, invalid-UTF-8 rejection, abort handling, unconditional and version-guarded full-file writes, `createIfAbsent`/`replaceIfVersion` semantics, parent-directory creation, non-regular target rejection, literal edit success/failure, unique-match enforcement, replace-all behavior, line-ending preservation, stale-version rejection (guarded edit against an old version), and structured `FsError` codes. The observed-state/owner-derivation policy is NOT here — it lives in `dsh-fs-policy` and is tested there.
|
||||
|
||||
Beyond the happy/sad paths above, `dsh-fs-local` tests must cover the defensive-pattern classes this repo has been bitten by:
|
||||
|
||||
- **Atomic-write temp-file safety**, not just cleanup. The atomic replace must write its temp file into a private (`0700`) directory, with a random name and an exclusive owner-only (`'wx'`, `0o600`) open, mirroring the bash spill-file rules — predictable world-readable temp paths invite symlink races and disclosure. Assert the temp file's permissions and that a pre-existing temp path does not get clobbered, alongside the existing cleanup-on-failure path.
|
||||
- **Implementation requirement:** `dsh-fs-local` write/edit use the same private-temp primitive: a random `0700` staging directory next to the target, an exclusive `0o600` temp file, cleanup on failure, and a final atomic rename. Do not move this RFC to `implemented/` if that primitive regresses or is deliberately revised.
|
||||
- **`targetKey` identity through symlinks.** Two different input paths that resolve to the same realpath must share one file-state entry: a `read` via path A must satisfy the read-before-edit guard for an `edit` via symlink path B, and a stale write through one path must be detected through the other. This is the contract that makes the stale guard correct, so test it directly.
|
||||
- **Concurrency / stale races.** The RFC names edit as race-prone (see Risks). Test that two concurrent write/edit operations against the same target settle deterministically: one succeeds and the other is rejected with `FS_STALE_VERSION` rather than silently overwriting, and that a successful edit refreshes recorded state so an immediately-following edit by the same owner proceeds.
|
||||
- **HMR safety and disposal.** `dsh-fs-local` registers `ctx.fs` and owns the in-memory file-state store, so it needs its own HMR-safety test (register the backend on a fiber, dispose it, assert the `ctx.fs` provider is withdrawn and the file-state store is released — a later provider starts with no inherited state).
|
||||
|
||||
`dsh-tool-fs` tests cover the consumer surface against the real `dsh-fs-local` provider (mock only the model/clock, not the collaborator). They should verify tool schemas, argument validation, prompt-section registration, formatting of successful results, propagation of backend `FsError` codes into `isError` tool results through `ctx.tools.execute()`, that read/write/edit dispatch the `fs/*` events (passing the execution context as the actor), root-plugin suite registration, and HMR cleanup of both tool schemas and prompt sections.
|
||||
|
||||
Integration tests should load `dsh-fs-local` plus `dsh-tool-fs` (and, for the default deployment, `dsh-fs-policy`) and execute `read`, `write`, and `edit` through `ctx.tools.execute()` to prove the packages work together without bypassing the tool registry — including a bare-provider path (no `dsh-fs-policy`) where an unread edit/overwrite succeeds. They must verify the world, not the tool's self-report: after a `write`/`edit`, read the file back from disk and assert byte-identical content (and that untouched files are unchanged), rather than trusting the returned `ContentBlock[]`. Each integration/e2e test owns its resources — create the harness in the test, run against a per-test temporary directory, and dispose the harness and remove the directory in `afterEach` even on failure or timeout.
|
||||
|
||||
Repo gates for the implementation include the focused vitest suites, `pnpm run typecheck`, `pnpm run test:coverage` for runtime code, and build/publint coverage after adding package entrypoints.
|
||||
|
||||
## Risks
|
||||
|
||||
**`cwd` can be mistaken for a sandbox.** The local backend's base directory is a resolution default, not automatically a containment boundary. If containment is required, it must be enforced by the backend contract or by a permission/sandbox plugin on `tools/execute`.
|
||||
|
||||
**The interface can become too local.** Returning fields such as `absolutePath` from `ctx.fs` would make remote, sandboxed, or virtual backends awkward. The contract should expose display metadata without requiring consumers to understand host paths.
|
||||
|
||||
**The interface can become too thin.** If `ctx.fs` only mirrors `node:fs` primitives, `tool-fs` will reimplement binary detection, pagination, atomic writes, and edit semantics. That recreates the coupling this RFC is trying to avoid.
|
||||
|
||||
**Edit semantics are race-prone.** Literal edit is a read-modify-write operation. Without a stale-content guard or backend-level atomic edit primitive, concurrent edits can overwrite each other. The first implementation should document its guarantees clearly; stronger compare-and-swap semantics can be added later if needed.
|
||||
|
||||
**Observed state does not belong on `ctx.fs`.** Recording what an execution context has seen is workflow policy, not raw filesystem I/O. This RFC first placed it inside the filesystem seam; the split-fs-seam RFC then established that a sandboxed/remote backend should not inherit model-facing observation policy, and moved it into the `dsh-fs-policy` plugin. The provider seam keeps only what write/edit safety genuinely needs at the storage layer — a backend-minted version token and an optional version-guarded mutation — while the policy plugin owns owner derivation, observed-state, and read-before-edit gating over the `fs/*` events.
|
||||
|
||||
**The `resolve`-then-operate shape costs an extra round-trip per call.** Each tool may resolve a path to an `FsTarget` and then issue the read/write/edit as a separate `ctx.fs` call. For the local backend this is negligible (resolution is in-memory path normalization), but a remote/sandboxed backend may turn each step into its own request, so a single `read` can become two network round-trips. Backends where the round-trip matters can cache or fold resolution internally while preserving the observable contract.
|
||||
|
||||
**File-state persistence is deferred.** The first implementation can keep file state in memory. Resumed sessions should conservatively require files to be read again before write/edit tools accept updates until a future session-event or persistence mechanism makes file state replayable.
|
||||
|
||||
**Error codes become part of the seam.** `FsError` codes make stale-version and observation failures machine-routable through the existing structured error taxonomy. The cost is that `dsh-fs` imports the shared `HarnessError` base from `dsh-llm`; that dependency is intentional and should stay limited to the error vocabulary.
|
||||
|
||||
**Package churn is front-loaded.** The three-package split adds boilerplate before there is more than one backend. This is intentional: filesystem access is a likely sandbox/remote boundary, and changing the package surface after shipping model-facing tools would be more expensive.
|
||||
@@ -12,7 +12,7 @@ The three seams shipped across a stacked chain of PRs (the queue-aware cancel, t
|
||||
|
||||
### 1. Queue-aware `Agent.cancel(reason?)`
|
||||
|
||||
A new `cancel()` verb on the `Agent` interface (distinct from the narrower step-only `abort()`). It clears the inbox's queued + steering FIFOs, aborts the in-flight step if any, and drives a **turn-scoped cancellation marker** the driver loop checks at every turn-decision point — so a prompt that is queued-but-not-yet-started never runs, a cancel landing in the pre-step / continuation window drops the about-to-run turn (ending it `aborted`), and a later prompt cannot be batched into the cancelled turn. `whenIdle()` reaches post-cancel quiescence. ACP `session/cancel` maps to `cancel()`. The marker is armed ONLY when there is something to cancel, so an idle no-op cancel cannot strand the next prompt.
|
||||
A new `cancel()` verb on the `Agent` interface — the single public stop primitive. (It originally shipped alongside a narrower step-only `abort()`; that verb was later removed as unused, leaving `cancel()` the only public way to stop work.) It clears the inbox's queued + steering FIFOs, aborts the in-flight step if any, and drives a **turn-scoped cancellation marker** the driver loop checks at every turn-decision point — so a prompt that is queued-but-not-yet-started never runs, a cancel landing in the pre-step / continuation window drops the about-to-run turn (ending it `aborted`), and a later prompt cannot be batched into the cancelled turn. `whenIdle()` reaches post-cancel quiescence. ACP `session/cancel` maps to `cancel()`. The marker is armed ONLY when there is something to cancel, so an idle no-op cancel cannot strand the next prompt.
|
||||
|
||||
### 2. `AgentHandle` async disposer
|
||||
|
||||
|
||||
@@ -0,0 +1,65 @@
|
||||
# RFC: Session surface — a linked list over the event log for LLM message derivation
|
||||
|
||||
Status: implemented (accepted 2026-06-18)
|
||||
|
||||
## Context
|
||||
|
||||
The `Session` event log is the single source of truth ([event-sourced sessions](2026-06-11-event-sourced-sessions.md)), but the only view over it was `deriveMessages()` — a linear scan that filtered and transformed raw events into `Message[]`. This creates problems for session-history-manipulating plugins (compaction, tool-call result pruning, etc.). Without a central mechanism, each plugin would need to wrap `agent/request` to rewrite the message list — a pattern that suffers from listener-ordering fragility, provides no durable record of what was changed, and forces repeated changes to the core `deriveMessages()` whenever a new manipulation is added. A central hub in the `session` package, with a provenance-recording mechanism and enough flexibility for future plugins to manipulate session history through a stable API, lays a solid foundation for plugin development.
|
||||
|
||||
## Decision
|
||||
|
||||
Add a **surface** — a derived, cached linked list of "surface nodes" (the subset of events that produce LLM messages) — maintained by `surfaceOp` markers in the event log.
|
||||
|
||||
### Two new top-level fields on `SessionEvent`
|
||||
|
||||
Every `SessionEvent` gains two optional fields (structural metadata, like `seq`/`time`):
|
||||
|
||||
- **`sourceEventSeqs?: number[]`** — seq numbers of events that are provenance sources (e.g., the `assistant/chunk` seqs that built an `assistant/message`, or the surface nodes shadowed by a compaction marker). Provenance is a core design principle; without it, the replace-range operation cannot be validated on replay.
|
||||
- **`surfaceOp?: SurfaceOp`** — how this event entered the surface. Absent for non-surface events.
|
||||
|
||||
### SurfaceOp: two operations
|
||||
|
||||
```ts
|
||||
export type SurfaceOp =
|
||||
| 'append' // normal tail append
|
||||
| { op: 'replace'; start: number; end: number } // shadow [start, end] inclusive
|
||||
```
|
||||
|
||||
1. **Append** — add a new node to the tail. Used by `user/message`, `assistant/message`, `tool/result`, `context/message`, `steering/message`. The loop passes `surfaceOp: 'append'` on all such appends, and `sourceEventSeqs` where applicable (e.g., `assistant/message` records its `assistant/chunk` sources; `tool/result` records its `tool/call` source).
|
||||
|
||||
2. **Replace** — remove nodes from `start` through `end` (both inclusive) and insert a new node in their place. Both `start` and `end` must be valid surface node seqs in the current surface; `start === end` replaces a single node. The node's `sourceEventSeqs` must contain every shadowed surface node. The shadowed events remain in the log but are no longer on the surface.
|
||||
|
||||
The both-ends-inclusive design was chosen over half-open `[start, endExclusive)` because the surface is a doubly-linked list — both ends are naturally named by node seqs, and single-node replacement (`start === end`) is a common case that reads naturally with inclusive semantics.
|
||||
|
||||
### SurfaceManager: delta-based, not full rebuild
|
||||
|
||||
A `SurfaceManager` class (private to `Session`) maintains the cached linked list. It tracks `_lastProcessedSeq` and processes only the **delta** (new events since the last access) rather than rescanning the entire log. Because the log is append-only, prior events never change — full rebuild is only needed after a wholesale log replacement (e.g., seeding).
|
||||
|
||||
Why delta processing? The naive approach (a dirty flag + full rebuild on every access) would be O(N²) over a session's lifetime — every single-event append triggers a complete scan of all prior events. Delta processing is O(1) when no new events and O(new events) when new events arrive.
|
||||
|
||||
`deriveMessages()` uses the surface when surface markers exist, falling back to the existing linear scan for sessions without markers (backward compatibility).
|
||||
|
||||
### Persistence
|
||||
|
||||
The new fields are serialized as top-level JSON properties. The JSONL backend requires zero changes — `JSON.stringify`/`JSON.parse` preserve everything transparently. The SQLite backend's `events` table carries two nullable TEXT columns (`source_event_seqs`, `surface_op`). The on-disk `SCHEMA_VERSION` is bumped to reflect the column set, and — per the pre-release bump-and-reject policy — a database written by any other build is REJECTED on open rather than migrated (there is no persisted user data to upgrade). The session format `version` is pinned at `SESSION_FORMAT_VERSION = 0` (the "unstable / pre-release" stance): the optional surface fields are absorbed without bumping it.
|
||||
|
||||
### Crash recovery
|
||||
|
||||
The `repair.ts` module synthesizes `tool/result` closers for orphaned tool calls after a crash. These closers carry `surfaceOp: 'append'` and `sourceEventSeqs` pointing to the orphaned `tool/call` event, so the rehydrated surface is valid.
|
||||
|
||||
### Invariants
|
||||
|
||||
The dev-mode invariants plugin validates: `sourceEventSeqs` references (non-empty, no duplicates, references earlier events, references known seqs) and `surfaceOp` (replace `start ≤ end`, both endpoints are on the tracked surface, the range is non-reversed in surface position, and `sourceEventSeqs` includes every node the range shadows).
|
||||
|
||||
Because the surface is the SOLE derivation path, a surface-eligible event that carries no `surfaceOp` marker is invisible to `deriveMessages()` — it would land in the log yet silently drop from history on resume/fork. `append`'s typed overload makes the marker mandatory for `SurfaceEventType` events at compile time, but only when the type argument is a SPECIFIC literal; when it widens to the `SessionEventType` union (a caller iterating raw events, e.g. `for (const e of log) append(e.type, e.data)`) the conditional rest collapses to optional and the compiler stops enforcing it. The marker requirement is therefore ALSO checked at runtime in two places: `append` itself throws on a marker-less surface-eligible event (covering the union-widening loophole), and the `Session` seed constructor re-checks the same invariant (alongside its seq-contiguity and JSON-serializability checks) so a seed/load/fork — which arrives as raw `SessionEvent[]`, bypassing `append` — is REJECTED rather than constructing a session that resumes with missing history. (No backward-compat path for surface-less logs: per the pre-release stance there is no persisted user data to preserve, so such a log is rejected, not upgraded.)
|
||||
|
||||
## Consequences
|
||||
|
||||
- **`packages/core/session`**: New `surface.ts` (`SurfaceManager`), new types (`SurfaceOp`, `SurfaceIntent`), new fields on `SessionEvent`, modified `append()` (third required `SurfaceIntent` param), refactored `deriveMessages()` (walks the surface as the sole derivation path), surface-aware `repair.ts`. The seed constructor rejects a surface-eligible seed event missing its `surfaceOp` marker (see § Invariants).
|
||||
- **`packages/core/agent-loop`**: All surface-capable appends pass surface opts. Chunk seqs are collected for `assistant/message` provenance; `tool/call` seqs are captured for `tool/result` provenance.
|
||||
- **`packages/session-persistence/session-persistence-sqlite`**: Two new nullable TEXT columns (`source_event_seqs`, `surface_op`) on the `events` table; `SCHEMA_VERSION` bumped (bump-and-reject, no migration).
|
||||
- **`packages/support/invariants`**: Surface-related validation rules.
|
||||
- **`packages/session-persistence/session-persistence-jsonl`**: No changes required.
|
||||
- **`packages/session-persistence/session-persistence`**: Abstract interface unchanged.
|
||||
|
||||
The surface is the foundation for future history manipulation. A compaction or tool-result-prune plugin appends one of the existing message-producing event types (a `user/message` carrying the summary, say) with `surfaceOp: { op: 'replace', start, end }` and `sourceEventSeqs` covering the shadowed nodes — the new node takes the range's place on the surface while the plugin's own trace events (e.g. `compaction/start`, `compaction/end`) stay off it. Replay preserves the decision deterministically.
|
||||
@@ -4,24 +4,24 @@ Status: implemented (proposed and accepted 2026-06-18, implemented 2026-06-20)
|
||||
|
||||
## Problem
|
||||
|
||||
`dsh-session-persistence-jsonl` and `dsh-session-persistence-sqlite` intentionally prove the same `SessionPersistence` contract over different storage media, but their write-path orchestration was duplicated: per-session state, `session/created` adoption, backend-specific prefix reads, write-behind buffers, serialized flush chains, HMR seeding, and dispose drains. The pure seed-prefix collision and serializability guards had already moved into the seam package; the remaining orchestration was still correctness-heavy and received the same fixes twice. A code-level diff showed the two backends were byte-identical — or same-algorithm — for ALL of it: the four maps (`states`/`buffers`/`chains`/`inits`), `installWritePath`, `initFor`, `onCreated`'s four cases, `flush`, `drain`, `serialize`, `adopt`, `adoptLivePrefix`, `assertVersion`, and the `create`/`append`/`load`/`has`/`delete` skeletons. Only the storage primitives (write bytes vs. INSERT rows) differed.
|
||||
`dsh-session-persistence-jsonl` and `dsh-session-persistence-sqlite` intentionally prove the same `SessionPersistence` contract over different storage media, but their write-path orchestration was duplicated: per-session state, `session/created` adoption, backend-specific prefix reads, write-behind buffers, serialized flush chains, HMR seeding, and dispose drains. The pure seed-prefix collision and serializability guards had already moved into the seam package; the remaining orchestration was still correctness-heavy and received the same fixes twice. A code-level diff showed the two backends were byte-identical — or same-algorithm — for ALL of it: the four maps (`states`/`buffers`/`chains`/`inits`), `installWritePath`, `initFor`, `onCreated`'s four cases, `flush`, `drain`, `serialize`, `adopt`, `adoptLivePrefix`, `assertVersion`, and the `create`/`append`/`load` skeletons. Only the storage primitives (write bytes vs. INSERT rows) differed.
|
||||
|
||||
## Decision
|
||||
|
||||
Extract a backend-agnostic `PersistenceCoordinator` into `dsh-session-persistence`. The coordinator owns the orchestration once; each first-party backend composes one (`new PersistenceCoordinator(ctx, this)`), implements a small `PersistenceBackend` hook interface, and delegates its six public service methods (`create`/`append`/`load`/`list`/`has`/`delete`) to it.
|
||||
Extract a backend-agnostic `PersistenceCoordinator` into `dsh-session-persistence`. The coordinator owns the orchestration once; each first-party backend composes one (`new PersistenceCoordinator(ctx, this)`), implements a small `PersistenceBackend` hook interface, and delegates its four public service methods (`create`/`append`/`load`/`list`) to it.
|
||||
|
||||
Composition, not inheritance. The coordinator is a concrete class the backend holds, not a base class the backend extends. The RFC's risk — "a coordinator must not make unusual backends fight an inheritance hierarchy" — is avoided: a backend exposes only the hooks; it cannot reach the coordinator's private orchestration state, and the public `SessionPersistence` service shape is unchanged, so a third-party backend MAY still implement the abstract service directly without the coordinator at all.
|
||||
|
||||
### The hook interface (`PersistenceBackend<TornMarker>`)
|
||||
|
||||
Seven methods (six required + an optional lifecycle hook) — the only seam between the coordinator and storage:
|
||||
Six methods (five required + an optional lifecycle hook) — the only seam between the coordinator and storage:
|
||||
|
||||
- `name` — backend label for the dispose-failure `AggregateError`.
|
||||
- `loadStored(id)` — read a stored prefix by id, scanning ANY storage scope (every JSONL cwd bucket; SQLite's id is globally unique). Used by resume/load and, via `!== undefined`, the create-collision probe and `has`.
|
||||
- `loadStored(id)` — read a stored prefix by id, scanning ANY storage scope (every JSONL cwd bucket; SQLite's id is globally unique). Used by resume/load and, via `!== undefined`, the create-collision probe.
|
||||
- `loadLive(id, cwd)` — read a stored prefix SCOPED to `cwd`. **Deliberately distinct from `loadStored`**: HMR live-adoption must only adopt a persisted log at the SAME cwd as the live session; a same-id log at a different cwd is a collision, not a resume. Collapsing the two reintroduces a cross-cwd adoption bug. SQLite ignores `cwd`.
|
||||
- `appendBatch(meta, events, isMaterialized)` — durably append a contiguous batch, lazily materializing the session ATOMICALLY when not yet materialized (the materialize-write and the first event batch must commit together — a crash between them must not leave a materialized-but-empty session; this is why there is no separate `materialize` hook).
|
||||
- `commitRepair(meta, tornMarker, closers)` — make a crash repair durable: truncate the torn tail (iff `tornMarker !== undefined`) and append `closers`. **NOT required to be atomic** — JSONL legitimately truncates-then-appends in two fsync'd steps, SQLite does DELETE+INSERT in one transaction. Used by `load` (truncate + synthetic closers) and live-adoption (truncate only, `closers = []`).
|
||||
- `deleteStored(id)` / `list()` — remove a stored artifact / list all stored metadata.
|
||||
- `list()` — list all stored metadata.
|
||||
- `close?()` — optional lifecycle teardown (SQLite closes its db handle; JSONL omits it), awaited in the dispose effect AFTER the quiescence drain so a close failure never masks a drain error.
|
||||
|
||||
### The opaque torn marker
|
||||
@@ -34,4 +34,4 @@ The shared `runPersistenceContract` (public-API contract) keeps running for ever
|
||||
|
||||
## Risks and what we gave up
|
||||
|
||||
The pre-extraction duplication was verbose but explicit — each backend read top-to-bottom. The coordinator adds one indirection (the hook seam) and one new concept (the opaque torn marker). This clears the bar because the centralized logic is the correctness-heavy part that was already being fixed twice, and the hook set is narrow (seven methods, no inheritance). The hook surface was deliberately held to the minimum: `has` and the create-collision probe are NOT separate hooks — they fold into `loadStored(id) !== undefined`; there is no separate `materialize` hook (folded into `appendBatch` for atomicity); `list()` stays a backend method with no coordinator pass-through (listing needs none of the orchestration). The net effect is a reduction: one orchestration copy instead of two, the backends shrank by ~1200 lines of duplicated churn, and a future backend implements ~7 small primitives instead of copying the entire `session/event` → buffer → flush machinery.
|
||||
The pre-extraction duplication was verbose but explicit — each backend read top-to-bottom. The coordinator adds one indirection (the hook seam) and one new concept (the opaque torn marker). This clears the bar because the centralized logic is the correctness-heavy part that was already being fixed twice, and the hook set is narrow (six methods, no inheritance). The hook surface was deliberately held to the minimum: the create-collision probe is NOT a separate hook — it folds into `loadStored(id) !== undefined`; there is no separate `materialize` hook (folded into `appendBatch` for atomicity); `list()` stays a backend method with no coordinator pass-through (listing needs none of the orchestration). The net effect is a reduction: one orchestration copy instead of two, the backends shrank by ~1200 lines of duplicated churn, and a future backend implements a handful of small primitives instead of copying the entire `session/event` → buffer → flush machinery.
|
||||
|
||||
68
docs/rfc/implemented/architecture/2026-06-20-branded-ids.md
Normal file
68
docs/rfc/implemented/architecture/2026-06-20-branded-ids.md
Normal file
@@ -0,0 +1,68 @@
|
||||
# RFC: Branded IDs everywhere they belong
|
||||
|
||||
Status: implemented (proposed and accepted 2026-06-20)
|
||||
|
||||
## Problem
|
||||
|
||||
The harness already brands three identifiers — `CallId` (`packages/llm/llm/src/brand.ts`), `SessionId` (`packages/core/session/src/types.ts`), and `AgentId` (`packages/core/agent/src/types.ts`) — using the `Branded<B> = string & { readonly [BRAND]: B }` machinery (owned by the type-only `@deepseek-ai/dsh-brand` package at `packages/util/brand/` — see its [README](../../../../packages/util/brand/README.md)) and a zero-cost cast factory per type. `dsh-brand` also states the governing policy: *"Branding is for ids that cross package boundaries and could plausibly be confused; not every string needs a brand."* That policy is right; the problem is that it is only half-applied. Two gaps let a structurally-identical-but-semantically-wrong string slip through the type checker today.
|
||||
|
||||
**Gap 1 — unbranded cross-boundary IDs in the bash seam.** The background-task id is a plain `string`: `BashTask.id: string` (`packages/bash/bash/src/types.ts`), carried as `string` through the whole executor seam (`BashExecutor.get`/`ownerOf`/`readOutput`/`kill(id: string)` in `packages/bash/bash/src/index.ts`) and validated/passed as `string` by the model-facing tools (`validateTaskId`, `assertTaskAccess`, the `task_id` schema arg in `packages/bash/tool-bash/src/index.ts`). It is generated by a per-executor counter — `` `bash-${this.nextTaskId++}` `` in `packages/bash/bash-local/src/index.ts` — which gives it **exactly the same `name-N` shape as `SessionId`'s default** (`` `session-${++counter}` `` in `packages/core/session/src/index.ts`). A bash task id and a session id are trivially swappable at a call site and the compiler says nothing. This is the headline case the user asked about, and it is a model-facing id (the model passes `task_id` back to `bash_output`/`bash_kill`), so a confusion here is reachable from untrusted input.
|
||||
|
||||
The bash **owner token** is the related sub-case: `BashExecRequest.owner?: string` and `BashExecSpec.owner: string | undefined` (`packages/bash/bash/src/types.ts`) are documented as a deliberately *opaque* isolation key, but in every live caller the value IS the owning agent's `session.header.id` (`callerToken = (exec) => exec.agent?.session.header.id` in `packages/bash/tool-bash/src/index.ts`) — i.e. a `SessionId` wearing a `string` disguise. It is compared for access control (`owner !== callerToken(exec)`), so a mismatched-but-well-typed string here is a cross-session isolation bug the type system currently cannot catch. This is the same `session.header.id`-as-owner alias that the [unify-the-agent-id-and-the-session-id](../../proposed/simplification/2026-06-20-unify-agent-and-session-id.md) proposal calls the "bash owner-token alias hole".
|
||||
|
||||
**Gap 2 — brand erosion at the seams of the *already-branded* IDs.** Even `CallId`/`SessionId`/`AgentId` decay back to bare `string` at exactly the places confusion is most likely: the registry/store `Map` key types and most public method params. Representative sites: `SessionStore.store = new Map<string, Session>()` and `create`/`prepare(id?: string)`/`get(id: string)` (`packages/core/session/src/index.ts`); `AgentRegistry.store = new Map<string, Agent>()` and `register`/`get(id: string)` (`packages/core/agent/src/index.ts`); `ToolPresenter.pending = new Map<string, …>()` keyed by call id and `call(callId: string)`/`result(callId: string)` (`packages/ui/acp/src/index.ts`); the ACP session-id surface beyond the store map — `SessionRecord.sessionId: string`, `bySession = new WeakMap<Agent, string>()`, `loadingIds = new Set<string>()`, `requireSession(sessionId: string)`, and the exported `streamSessionEventUpdate(sessionId: string, …)` (`packages/ui/acp/src/index.ts`); and the persistence coordinator's `Map<string, …>` keyed by session id (`packages/session-persistence/session-persistence/src/coordinator.ts`). A brand that is dropped at the `Map` key buys nothing on lookups — the value of the existing brands is partly unrealized.
|
||||
|
||||
## Proposal
|
||||
|
||||
A type-only change. Brands are zero-cost casts; nothing about runtime behavior, serialization, comparison, or the wire format changes. The work is in three parts, all honoring the existing "not every string" policy.
|
||||
|
||||
- **Brand the bash task id.** Add `BashTaskId = Branded<'BashTaskId'>` plus its same-named factory in `packages/bash/bash/src/types.ts` (the package that *owns* the id), importing `Branded` from `@deepseek-ai/dsh-brand` exactly as `SessionId`/`AgentId` already do. The brand primitive lives in the dependency-free `dsh-brand` utility package precisely so `dsh-bash` can brand its ids by depending on it alone — it never pulls in `dsh-llm` (or `dsh-session`) just to reach `Branded`. Thread it through `BashTask.id`, the `BashExecutor` seam methods (`get`/`ownerOf`/`readOutput`/`kill`), the generation site in `dsh-bash-local` (brand the counter output once, at creation), and the `dsh-tool-bash` validate/access surface (`validateTaskId` returns a `BashTaskId`; `task_id` is branded at the tool boundary where the model's string arrives).
|
||||
|
||||
- **Mint a distinct `OwnerToken` brand.** Add `OwnerToken = Branded<'OwnerToken'>` in `packages/bash/bash/src/types.ts`; type `BashExecRequest.owner` / `BashExecSpec.owner` / `BashExecutor.ownerOf` as `OwnerToken | undefined`. The `dsh-tool-bash` consumer casts the agent's `session.header.id` (a `SessionId`) into an `OwnerToken` at the boundary — the one place the two vocabularies meet. The bash seam never imports `dsh-session`. (Rationale in the next section.)
|
||||
|
||||
- **Stop the brand erosion.** Propagate the existing brands to the `Map` key types and public method params listed under Gap 2 — `Map<SessionId, Session>`, `get(id: SessionId)`, `Map<AgentId, Agent>`, `Map<CallId, …>`, the ACP `SessionRecord.sessionId: SessionId` surface, the coordinator's `Map<SessionId, …>`. This is the larger mechanical share of the diff and the part that makes the *existing* brands actually load-bearing on lookups, not just on the struct fields.
|
||||
|
||||
Illustrative shape (the factory pattern is identical to the three existing brands):
|
||||
|
||||
```ts ignore-check
|
||||
import type { Branded } from '@deepseek-ai/dsh-brand'
|
||||
|
||||
/** A background bash task handle (generated `bash-N` by the local executor). */
|
||||
export type BashTaskId = Branded<'BashTaskId'>
|
||||
export function BashTaskId(id: string): BashTaskId {
|
||||
return id as BashTaskId
|
||||
}
|
||||
|
||||
/** A bash task's opaque isolation key — the consumer's owner identity, NOT the bash seam's. */
|
||||
export type OwnerToken = Branded<'OwnerToken'>
|
||||
export function OwnerToken(id: string): OwnerToken {
|
||||
return id as OwnerToken
|
||||
}
|
||||
```
|
||||
|
||||
## Why a distinct OwnerToken brand (not SessionId)
|
||||
|
||||
The obvious shortcut is to type `owner` as `SessionId` directly — it always *is* one. We reject that. The bash executor seam is a capability seam (interface `dsh-bash`, implementation `dsh-bash-local`, consumer `dsh-tool-bash`) and its owner token is *documented as deliberately opaque*: the executor "never interprets it (no access policy lives in the seam — that is the consumer's job)" (`packages/bash/bash/src/types.ts`). Typing the seam's field as `SessionId` would import `dsh-session`'s vocabulary into a package that must not know what an owner token *means* — it would couple a generic execution backend to the session model and contradict the opaque-token design. A sandboxed or remote executor that replaces `dsh-bash-local` should not inherit a session dependency. The distinct `OwnerToken` brand keeps the seam decoupled: `dsh-bash` knows only "an owner is some opaque branded token," and the `dsh-tool-bash` consumer — which already decides the access policy — is the single boundary that casts its `SessionId` into an `OwnerToken`. The brand still delivers the safety win (you cannot pass a `BashTaskId` or a raw string where an owner is expected) without the coupling.
|
||||
|
||||
## Out of scope / possible extensions
|
||||
|
||||
Kept deliberately narrow per the "not every string needs a brand" policy. Each of these is a plausible future brand, deferred with a reason, not a commitment:
|
||||
|
||||
- **`ModelId`** (`GenerateOptions.model`, the `LlmService` adapter-registry key) — a real cross-package lookup key (config → agent → llm → adapter); a reasonable next brand, left out only to keep this RFC's blast radius focused.
|
||||
- **`ToolName`** (the `ToolRegistry` key) — author-defined, human-readable, and rarely confused with another id; the weakest candidate, likely not worth a brand.
|
||||
- **`ErrorCode`** (`HarnessError.code`) — a closed vocabulary (`ABORTED`, `NO_ADAPTER`, …), not a per-instance id; better served by a string-literal union than a brand, if anything.
|
||||
- **Numeric ordinals** — turn number, step number, and the event `seq` are `number`, not `string`, so `Branded<string>` does not apply; a parallel `number & { readonly [BRAND]: B }` variant could brand them, but they are positional ordinals rarely passed across boundaries, so the payoff is low.
|
||||
- **Validated construction** — the brand factories are pure casts with no runtime check, and every boundary (ACP `sessionId`, provider-issued `call.id`, the empty-string fallback in `dsh-llm-deepseek`) trusts the raw string today. A `SessionId.parse()` / `isValid()` companion that throws on malformed input at boundaries is a genuine gap, but it is a *runtime-behavior* change with its own design (what is "malformed"? what do we do on failure?) and belongs in its own RFC, not bundled into this type-only pass.
|
||||
|
||||
## Acceptance criteria
|
||||
|
||||
- `BashTaskId` and `OwnerToken` are defined in `dsh-bash` and threaded end-to-end: the executor seam, the `dsh-bash-local` generation site, and the `dsh-tool-bash` model-facing surface all speak the brands; `dsh-bash` gains no dependency on `dsh-session`.
|
||||
- No collection keyed by an in-scope branded id (`CallId`/`SessionId`/`AgentId`/`BashTaskId`) is keyed by bare `string` — this covers `Map`, `WeakMap` value slots, and `Set` membership (e.g. the ACP `bySession`/`loadingIds`), not just `Map<string, …>`; the corresponding public method params and exported function signatures (e.g. `streamSessionEventUpdate`) take the brand, not `string`.
|
||||
- Brands are constructed via the cast factory at each boundary where a raw string enters (provider call id, ACP session id, model-supplied `task_id`); no `as` casts scattered at call sites.
|
||||
- `pnpm run typecheck` and `pnpm run doc-sync` are green; the change is observably type-only (no snapshot, no e2e behavioral diff).
|
||||
|
||||
## Risks / what we give up
|
||||
|
||||
- **Mechanical churn across two surfaces.** Propagating brands touches the bash seam (interface + impl + consumer) and the ACP session-id surface plus the persistence coordinator. The risk is broad but low-severity: a missed site is a compile error, not a silent bug. It ships as its own PR, converged with Codex, and stacks naturally near the [unify-the-agent-id-and-the-session-id](../../proposed/simplification/2026-06-20-unify-agent-and-session-id.md) work (both touch the session-id / owner-token boundary; if that proposal lands first, `OwnerToken` still stays distinct from the unified id for the decoupling reason above).
|
||||
- **Brands do not validate.** A brand is a confusability guard, not a correctness proof: a *wrong* session id that is still a well-formed string passes the type checker exactly as before. This RFC does not close that gap (see Out of scope) — it only stops the *category* error of passing the wrong *kind* of id.
|
||||
- **The "where to stop" line stays a judgment call.** Branding `BashTaskId` but not `ToolName`, `OwnerToken` but not `ModelId`, is a taste call about which strings "could plausibly be confused." Reasonable reviewers may want more or fewer; the policy in `brand.ts` is the tie-breaker, and this RFC errs toward the ids that are model-facing or used for access control.
|
||||
@@ -0,0 +1,53 @@
|
||||
# RFC: Extract example apps into packages
|
||||
|
||||
Status: implemented
|
||||
|
||||
## Problem
|
||||
|
||||
An example folder is supposed to be *thin* — the variable wiring of a demo, not the demo's machinery. Before this change it was thick. Each example carried a hand-rolled `start.ts` boot bootstrap, an infra preamble (`timer`, and — for the stdio demos — `logger` + `hmr`), nested includes of three shared YAML fragments (`base.yml` / `base-core.yml` / `acp-agent/acp-tail.yml`), and per-example `agent-loop`/persistence/system-prompt config. The actual app — the spine of services every agent needs — was spread across the leaf and those includes.
|
||||
|
||||
The deeper problem was a **coupled front-door cluster** that lived at the leaf with nothing enforcing it. Choosing the ACP bridge over `ui-stdio` was not one swappable line: an ACP server must **drop the stdout console logger** (stdout is the JSON-RPC channel — a stray log corrupts the frames) and pre-create **no** agents (ACP `session/new` creates them on demand), whereas the stdio app needs a console logger and a pre-created `main`. (`timer` is the one infra plugin common to both — it writes nothing to stdout — so it belongs in the shared spine, not the cluster.) That coupling was enforced only by prose warnings in the leaf YAML. A leaf that wired a console logger into the ACP config was a one-line, comment-only mistake away — exactly the [stdout-purity footgun](../feature/2026-06-18-acp-terminal-and-tool-rendering.md) the examples guarded by hand. The three `start.ts` files also duplicated the Loader-boot tail, the `.env` loader, and (for ACP) snapshot-mode branching and the stdin-dispose lifecycle.
|
||||
|
||||
## What shipped
|
||||
|
||||
Each example is now **mostly an invocation of an app package**, splitting the wiring along the existing [interface / implementation / consumer seam](2026-06-13-capability-seams.md): the **app package owns the composition**, the leaf `cordis.yml` owns only the **swappable choices** (which LLM adapter, which bash executor, model, prompt, persistence root).
|
||||
|
||||
- **`@deepseek-ai/dsh-agent-core`** ([packages/core/agent-core](../../../../packages/core/agent-core)) — a Cordis bundle plugin for the providerless, executor-less, UI-less spine: `timer` + `llm` + sessions + system-prompt + tools + agents + invariants + `tool-bash` + `agent-loop`, mounted as child plugins inside its `apply(ctx)` via `ctx.plugin(...)`. This is the old `base-core.yml` **minus** `bash-local`, **plus** `timer` and the loop, as code instead of a YAML include. The bundle **forwards** `agent-loop`'s `agents` list as its own config (`export const Config = AgentLoop.Config`, default `[]`, the existing `AgentLoop.Config` shape in [packages/core/agent-loop/src/index.ts](../../../../packages/core/agent-loop/src/index.ts)) — so each app supplies its own pre-created agents. This is precisely the reason the old `base-core.yml` gave for keeping `agent-loop` *out* of the shared core ("the examples disagree — stdio needs a pre-created `main`, acp needs none"); forwarding the config dissolves that objection — the loop is shared, the agents list is per-app. The bundle children register into the root service store, so a leaf-mounted sibling (the adapter, the executor) sees them exactly as a nested `plugin-include` subtree's services were seen before. Depending on the CONCRETE `dsh-agent-loop` (not just the `dsh-agent` interface) is deliberate and is the sanctioned exception to the "extension plugins depend on interfaces, never on the concrete loop" rule (packages/README.md, docs/architecture.md § Layering): the rule constrains plugins that EXTEND the system, whereas this bundle's whole job is to COMPOSE the concrete spine. Swapping the loop means publishing a different bundle, not rewiring every extension.
|
||||
- **`@deepseek-ai/dsh-stdio-agent`** ([packages/ui/stdio-agent](../../../../packages/ui/stdio-agent)) and **`@deepseek-ai/dsh-acp-agent`** ([packages/ui/acp-agent](../../../../packages/ui/acp-agent)) — app packages, each consuming `dsh-agent-core` and **baking in its coupled front-door cluster**: stdio = `ui-stdio` + console logger + a pre-created `main`; acp = the `acp` bridge + JSONL persistence + **no stdout logger** + no pre-created agents. The leaf no longer carries the cluster, so it has no logger entry to copy wrong by default — the common stdout-purity mistake loses its foothold. (A leaf can still *add* a sibling logger entry — a package cannot forbid what a leaf author writes — so the rule "never add a stdout logger to an ACP leaf" stays documented at the leaf; what changed is that the default leaf has nothing to get wrong.) They land under the existing `ui` group alongside `acp`, so no new package group (and no `tsconfig`/`packages/README` group plumbing) was needed.
|
||||
- **`start.ts` is gone.** Each app package exposes a `bin` (`dsh-stdio-agent` / `dsh-acp-agent`); the `demo:*` scripts invoke it (e.g. `dsh-stdio-agent ./cordis.yml`). The Loader-boot tail, `.env` loading, snapshot-mode selection, and stdin-dispose lifecycle moved into that bin, owned by the app. The `bin.ts` files are coverage-excluded (a self-executing CLI entry, like the old `start.ts`) and driven by the keyless Loader-path tests.
|
||||
- **Each leaf `cordis.yml` collapses** to backends + config: the LLM adapter (`llm-deepseek` with apiKey/models, or `llm-replay`), the bash executor (`bash-local`), `hmr` for the stdio demos (see the amendment below), and one app entry carrying the app's config (model, system prompt, persistence root — surfaced as the app package's own `Config`, which routes each value to wherever the app wires it: stdio onto its pre-created agent, acp onto the bridge plugin).
|
||||
- **echo-agent folds onto `dsh-stdio-agent`**, swapping the LLM backend to the local `mock-llm` and adding the local `echo-tool` (plus `bash-local`, which the spine's `tool-bash` injects) at the leaf — the clean demonstration of "swap the backend, keep the app". `mock-llm.ts` / `echo-tool.ts` stay as example-local teaching plugins.
|
||||
- **`base.yml`, `base-core.yml`, and `acp-agent/acp-tail.yml` are retired** — the spine they shared now lives in `dsh-agent-core`.
|
||||
|
||||
`bash-local` and the LLM adapter stay **leaf choices**: the bundle ships `tool-bash` (the consumer schema), the leaf picks the executor implementation, so a sandboxed executor or replay adapter swaps in without touching the app.
|
||||
|
||||
### Amendment on implementation: `hmr` stays a leaf entry
|
||||
|
||||
The proposal listed `hmr` among the stdio app's baked-in front-door cluster. Validating against the code, baking `hmr` into the `dsh-stdio-agent` package fights cordis in two ways, so it ships as a **leaf `cordis.yml` entry** instead:
|
||||
|
||||
1. `@cordisjs/plugin-hmr` is a Loader-only, subprocess-only dev plugin — its constructor throws without `node --expose-internals` + a live `loader` service, so it can only run in the real `demo:*`/bin subprocess, never in the in-process unit/coverage tier.
|
||||
2. The in-process test tier (vitest) cannot even *import* the vendored `hmr` module (its class-decorator `@Inject` form fails under Vite's transform), so a package whose `apply` statically imported it could never satisfy the per-file 100% coverage gate on its headline function.
|
||||
|
||||
Crucially, `hmr` is **not** a stdout-purity footgun the way the console logger is — a stray `hmr` in the ACP config would not corrupt the JSON-RPC frames — so leaving it at the leaf costs none of the safety the coupling argument is about. The **logger** (the real coupling) stays baked in: the stdio app includes it, the ACP app omits it.
|
||||
|
||||
## Why not keep the wiring in shared YAML includes?
|
||||
|
||||
The old `base*.yml`/`acp-tail.yml` includes already deduped the *config*, but a YAML include cannot **encapsulate** the front-door coupling — it can only describe it in a comment and trust every leaf to obey. It also cannot own a `bin`, so the boot glue stayed copied across three `start.ts` files. A package turns "the ACP app never logs to stdout" from a prose warning into a property of the artifact: there is no logger entry in the leaf to get wrong.
|
||||
|
||||
## Verification
|
||||
|
||||
- Each example directory is `cordis.yml` (+ the acp `cordis.snapshot.yml`) + `README.md` + tests only — no `start.ts`, no infra preamble; `base.yml`/`base-core.yml`/`acp-tail.yml` are gone.
|
||||
- `demo:echo` / `demo:repl` / `demo:acp` run via the app-package `bin`s.
|
||||
- The new packages carry the per-file 100% coverage gate and a README like every `@deepseek-ai/dsh-*`. Each app package has a keyless **real-load-path** smoke that boots it through its `bin` + the cordis Loader (not a hand-built `ctx.plugin({...})` mount), guarding the `unwrapExports` export-shape bug class ([postmortem 0001](../../../postmortem/0001-acp-default-export-drops-inject.md)).
|
||||
- The ACP snapshot **replay** transcript is unchanged: the boot restructuring preserved the plugin set + load order, so `pnpm run test:snapshot` stays green against the committed goldens with no re-record.
|
||||
|
||||
## What we give up
|
||||
|
||||
- **The bare-plugin-tree pedagogy.** echo-agent's inlined `cordis.yml` showed every plugin at once; the spine now lives behind a bundle, so seeing the whole tree means opening `dsh-agent-core`. The app package's README carries that teaching weight.
|
||||
- **A layer of indirection.** "What does this demo load?" becomes a package read, not a single YAML scan.
|
||||
|
||||
## Related
|
||||
|
||||
- Supersedes [Make the shared example base providerless](../../rejected/architecture/2026-06-20-providerless-example-base.md): renaming `base.yml` to the providerless core is moot once the spine moves into `dsh-agent-core` and the `base*.yml` files are deleted.
|
||||
- Builds on the [capability-seams](2026-06-13-capability-seams.md) interface/implementation/consumer split — backends and presentation stay leaf choices; the spine is the shared bundle.
|
||||
- Complements [Reorganize packages into a modular hierarchy](2026-06-20-package-hierarchy.md): the new app/core packages slot into existing groups under that hierarchy (`core` for the reusable spine bundle, `ui` for the app-specific front doors).
|
||||
@@ -51,7 +51,7 @@ packages/
|
||||
|
||||
The package list had been enumerated in five places. The uniform depth-2 layout lets most of them be derived instead:
|
||||
|
||||
- `tsconfig.base.json` and `tsconfig.typecheck.json` each map every package through a single `@deepseek-ai/dsh-*` `paths` wildcard listing one candidate per group, in place of 18 per-package entries. (One subtlety this introduced: a path candidate contains `/*/`, which a naive regex comment-stripper mistakes for a block comment — `scripts/doc-typecheck.ts` reads the `paths` map via the TypeScript JSONC API rather than stripping comments by hand for exactly this reason.)
|
||||
- `tsconfig.base.json` maps every package through a single `@deepseek-ai/dsh-*` `paths` wildcard listing one candidate per group, in place of per-package entries. Root `tsconfig.json` reuses that source map and carries the explicit project references that keep package/vendor typecheck boundaries intact. (One subtlety this introduced: a path candidate contains `/*/`, which a naive regex comment-stripper mistakes for a block comment — `scripts/doc-typecheck.ts` reads the JSONC config through TypeScript's parser rather than stripping comments by hand for exactly this reason.)
|
||||
- `scripts/publint-all.ts` derives its list by reading the hierarchy (`packages/<group>/<pkg>`), resolving the `TODO(package-inventory)`.
|
||||
- `tsconfig.build.json`'s project `references` stay an explicit list — TypeScript project references have no wildcard form. Generating these from a manifest is left to a follow-up (see [discover package inventories](../../proposed/process/2026-06-20-discover-package-inventory.md)).
|
||||
|
||||
|
||||
@@ -0,0 +1,80 @@
|
||||
# RFC: Mandatory `User-Agent` attribution for provider requests
|
||||
|
||||
Status: implemented
|
||||
|
||||
## Problem
|
||||
|
||||
LLM provider requests should identify the product making them. That is useful for provider-side support, abuse investigation, compatibility debugging, and traffic analytics. Before this RFC the harness only partially did this: the hand-rolled DeepSeek adapter sent a hand-copied `User-Agent` constant (`packages/llm/llm-deepseek/src/adapter.ts`), while the pi-ai-backed twin sent no harness-owned headers at all (`packages/llm/llm-pi-ai/src/adapter.ts`). New adapters could therefore omit attribution silently, and a library-backed adapter could drift from the hand-rolled adapter even though [the twin-adapter RFC](2026-06-13-twin-llm-adapters.md) exists to keep the provider seam honest across both implementations.
|
||||
|
||||
The immediate prompt came from OpenRouter's [App Attribution](https://openrouter.ai/docs/app-attribution) docs. OpenRouter creates app pages and rankings from `HTTP-Referer` plus display/category headers. That is valuable, but it is not the HTTP standard for application identity. The risk is adopting OpenRouter's exact header set as if it were universal, then leaking provider-specific headers to direct DeepSeek requests, future OpenAI/Anthropic/Vertex adapters, test servers, or proxies that log unknown fields indefinitely.
|
||||
|
||||
## Investigation
|
||||
|
||||
- **OpenRouter's mechanism is provider-specific.** Their current docs say app attribution is tracked through `HTTP-Referer` (required), `X-OpenRouter-Title`, and `X-OpenRouter-Categories`; `X-Title` is only accepted for backward compatibility. Their API reference calls the headers optional and says they make the app discoverable on OpenRouter. This is a concrete OpenRouter contract, not an IETF or OpenAI-compatible API standard.
|
||||
- **In agent tooling, `HTTP-Referer` is an OpenRouter-aware convention, not a general agent convention.** It is common enough that OpenRouter SDKs and OpenRouter examples expose it directly, and frameworks that target OpenRouter usually need a way to pass it through. But agent protocols such as ACP negotiate names, versions, and capabilities in their own initialize messages, while model-provider requests still need HTTP-level identity. "Accepted in the agent world" therefore means "recognized by OpenRouter integrations," not "portable across agent runtimes or providers."
|
||||
- **Observed coding agents use product/version `User-Agent` strings, sometimes with environment context.** A non-exhaustive public-code survey found OpenAI Codex building `{originator}/{version} ({os} {os_version}; {arch}) ...` and carrying an `originator` header; Google Gemini CLI sending `GeminiCLI[-clientName]/{version}/{model} ({platform}; {arch}; {surface})` or a Cloud Code VS Code variant; Cline's Codex backend client sending `cline/{version} ({platform} {release}; {arch}) node/{nodeVersion}` plus `originator: cline`; SWE-agent setting `swe-agent/{version}` unless the user already supplied a header; Continue setting `Continue/{version}` for its ClawRouter provider plus `X-Continue-Provider`. Aider also appends `Aider/{version} +{website}` to browser-like user agents for web scraping, but that is not a model-provider request path. The pattern is not one exact format; it is product identity in `User-Agent`, with provider-specific side headers only where a provider/backend asks for them.
|
||||
- **The standards-track general client identity header is `User-Agent`.** RFC 9110 section 10.1.5 defines `User-Agent` as the user-agent software identity, says it is used for interoperability reports and analytics, and says a user agent SHOULD send it on each request unless configured not to. This is the only standard header that directly matches "what product is making this HTTP request."
|
||||
- **`Referer` is standard, but OpenRouter's `HTTP-Referer` is not the standard field.** RFC 9110 section 10.1.3 defines `Referer` as the URI from which the target URI was obtained and spends significant text on privacy restrictions. OpenRouter instead asks for `HTTP-Referer`, using it as an app URL identifier. That name and meaning are OpenRouter-specific even though it resembles the CGI environment variable form of the standard `Referer` header.
|
||||
- **`From` is standard but not suitable as a mandatory default.** RFC 9110 section 10.1.2 defines `From` as an email address for the human responsible for a user agent. Robotic agents SHOULD send it so servers can contact an operator, but non-robotic agents should not send it without explicit user configuration because of privacy and security policy concerns. The harness can support an operator contact later, but must not invent one or require it globally.
|
||||
- **Request-body `user` or `metadata` fields are not app attribution.** Some model APIs expose a stable end-user identifier, request metadata, labels, or project/account headers. Those are useful for abuse monitoring, internal billing, dashboards, or trace correlation, but they either identify the end user rather than the product, are provider-specific body schema, or are not guaranteed to be forwarded through OpenAI-compatible gateways. They are not a substitute for a static application identity header.
|
||||
- **SDK telemetry headers identify the SDK, not the app.** Official and third-party SDKs often send library/version headers. Those help the SDK maintainer debug their client, but they do not identify the harness as the application unless the application explicitly supplies a product attribution layer.
|
||||
- **pi-ai has a first-class header hook.** `@earendil-works/pi-ai`'s `StreamOptions.headers` merges caller headers last over provider defaults, so a library-backed adapter can satisfy the same wire contract as the hand-rolled one without wrapping or upstream work. The mock-server suites assert arrival on the wire for both adapters.
|
||||
|
||||
## Decision
|
||||
|
||||
Provider request attribution is mandatory at the LLM adapter boundary, using the standard `User-Agent` header only. The rule: every product LLM adapter sends a static, non-secret application identity on every provider HTTP request, and every adapter has tests proving that `User-Agent` reaches the wire (a mock server asserting received headers; for a library-backed adapter, the library's header hook feeding the same mock-server assertion).
|
||||
|
||||
Do **not** implement OpenRouter app attribution in this RFC. `HTTP-Referer`, `X-OpenRouter-Title`, `X-Title`, and `X-OpenRouter-Categories` are OpenRouter-specific product-surface headers, not provider-neutral model-request attribution. They can be proposed later by an OpenRouter adapter or explicit OpenRouter mode, with its own privacy/product decision, tests, and docs. Until then, even requests pointed at OpenRouter send only the shared `User-Agent` attribution from this RFC.
|
||||
|
||||
The provider-neutral identity is owned by `dsh-llm` (`packages/llm/llm/src/attribution.ts`), not by individual adapters. `AppIdentity` contains only public product facts needed to build `User-Agent`, and the default `APP_IDENTITY` settles the values the proposal left open:
|
||||
|
||||
- product token for `User-Agent`: `deepseek-harness` (continuity with the pre-RFC wire value and the repo/org identity)
|
||||
- version: read from the owning package's manifest via `createRequire`, never a hand-copied constant
|
||||
- app URL: `https://github.com/deepseek-ai/deepseek-harness-sdk` - the planned public home; a `FIXME` in `attribution.ts` blocks release until that repository actually exists
|
||||
|
||||
The default is mandatory and non-empty. White-label deployments pass their own `AppIdentity` to `attributionHeaders(identity)` - the override seam is the function parameter, with no deployment config plumbing until a consumer needs it - and omission falls back to the harness default rather than suppressing attribution. There is no per-request API for the model, user prompt, session id, cwd, user email, API key owner, or local machine identity to influence these fields.
|
||||
|
||||
Wire mapping (`attributionHeaders`; header names lowercase in code - HTTP field names are case-insensitive on the wire):
|
||||
|
||||
| Target | Mapping |
|
||||
|---|---|
|
||||
| All HTTP-based adapters | `User-Agent: {product}/{version} (+{url})` - the parenthesized `+url` comment stays within RFC 9110's conservative product/comment syntax. |
|
||||
| Direct DeepSeek endpoint | `User-Agent`; do not send OpenRouter-only headers unless DeepSeek documents an equivalent contract. |
|
||||
| OpenRouter endpoints | `User-Agent` only for now. Do not send `HTTP-Referer`, `X-OpenRouter-Title`, `X-Title`, or `X-OpenRouter-Categories` under this RFC. |
|
||||
| Future providers | `User-Agent` only unless a later provider-specific RFC accepts additional headers. Do not reuse `HTTP-Referer` by analogy. |
|
||||
|
||||
Endpoint detection is not part of this RFC because no endpoint-specific mapping is accepted here. If OpenRouter support lands later, detection must be explicit: either a dedicated OpenRouter provider package or an explicit `provider: 'openrouter'` / `attributionTarget: 'openrouter'` config, not arbitrary path fragments or model names.
|
||||
|
||||
## Acceptance criteria (all landed)
|
||||
|
||||
- `dsh-llm` documents the mandatory `User-Agent` attribution contract for `LlmAdapter` authors (`LlmAdapter` JSDoc, package README, and the adapter-contract section of `docs/core-data-structures/llm-streaming.md`).
|
||||
- A shared helper (`attributionHeaders` / `userAgent`) constructs the app identity and the standard `User-Agent` value from package metadata, so adapters do not hand-copy version constants.
|
||||
- `dsh-llm-deepseek` sends the shared `User-Agent` on every request and its mock-server suite asserts the exact value.
|
||||
- `dsh-llm-pi-ai` sends the same `User-Agent` through pi-ai's `StreamOptions.headers` hook and its mock-server suite asserts the exact value.
|
||||
- No adapter sends OpenRouter-specific attribution headers (`HTTP-Referer`, `X-OpenRouter-Title`, `X-Title`, `X-OpenRouter-Categories`) as part of this RFC.
|
||||
- No app-attribution field carries secrets, local paths, session ids, prompt text, model output, user email, or per-user stable identifiers.
|
||||
- The adapter READMEs state the `User-Agent` attribution policy and explicitly avoid documenting OpenRouter app attribution as implemented behavior.
|
||||
|
||||
## Alternatives considered
|
||||
|
||||
**OpenRouter app attribution now.** Rejected for this RFC. Sending `HTTP-Referer` plus `X-OpenRouter-Title` would satisfy OpenRouter rankings, but those headers are a provider-specific product feature, not the provider-neutral model-request attribution this RFC is trying to standardize. Supporting them should be an explicit OpenRouter adapter/mode decision later, not hidden inside the first shared attribution helper.
|
||||
|
||||
**OpenRouter headers everywhere.** Rejected. It would treat a custom OpenRouter contract as a universal standard and send fields with misleading semantics to providers that did not ask for them. It also risks using `HTTP-Referer` as a generic app URL field even though standard HTTP already has `User-Agent` for product identity and `Referer` for a different browsing-context concept.
|
||||
|
||||
**Only provider account/project identity.** Rejected. Organization/project headers, API keys, cloud accounts, and billing projects identify who pays or owns the request, not which application is sending traffic. They also expose no public app title/category and do not help gateways like OpenRouter build app rankings.
|
||||
|
||||
**End-user `user`/`metadata` fields.** Rejected for this RFC. Those are valuable for abuse monitoring and customer support but describe the human or tenant behind a request. App attribution must be static product identity and safe to send on every request.
|
||||
|
||||
**Config-only opt-in attribution.** Rejected. A default-off setting is exactly how adapters keep drifting. The policy is mandatory default attribution with overrideable public values, not optional attribution.
|
||||
|
||||
**Product-named token (`deepseek-code`).** Considered for the `User-Agent` token, since the product's name is DeepSeek Code. `deepseek-harness` won on continuity: it is the identity providers already see from this codebase, it matches the org/repo and planned SDK-repo naming, and a public rename can change the product token deliberately later.
|
||||
|
||||
## Risks / what we give up
|
||||
|
||||
**Providers see that traffic comes from the harness.** That is the point, but it means deployments that previously blended into generic SDK traffic become identifiable. Mitigation: send only static public product data and let forks/white-label deployments pass their own `AppIdentity`.
|
||||
|
||||
**The app URL points at a repository that does not exist yet.** `deepseek-ai/deepseek-harness-sdk` is the planned public home; until it is created the URL is a dangling promise. The `FIXME` marker on the constant blocks a release from shipping with it unresolved (see `docs/development.md` marker semantics).
|
||||
|
||||
**Header support differs by client library.** The hand-rolled adapter sets headers directly; the pi-ai-backed adapter depends on pi-ai continuing to honor `StreamOptions.headers` (merged last over provider defaults). The wire-level mock-server tests are the guard: if a pi-ai upgrade stops delivering the header, the suite goes red. This is useful pressure on the abstraction: a provider adapter that cannot set mandatory headers cannot fully implement the harness LLM contract.
|
||||
|
||||
**OpenRouter rankings do not benefit yet.** `User-Agent` is the correct baseline for provider-neutral HTTP identity, but it will not create OpenRouter app pages or rankings because OpenRouter requires `HTTP-Referer` for that product feature. That is deliberate: public app marketplace participation is a separate product decision, not a prerequisite for mandatory request attribution.
|
||||
@@ -0,0 +1,392 @@
|
||||
# RFC: Web capability seam - stable tools over multiple providers
|
||||
|
||||
Status: implemented
|
||||
|
||||
## Problem
|
||||
|
||||
The harness needs model-facing web tools without binding the model contract to one vendor's API shape. Search is the immediate pressure point: the first version should support at least Exa search and Perplexity search — two deliberately different provider shapes (Exa returns a flat `results[]` of `{title, url, highlights, publishedDate}`; Perplexity returns a generated answer plus citations), which is what proves the normalized seam does not just mirror one vendor. Fetch is a separate capability: an anonymous public HTTP(S) fetch backend has transport, security, redirect, decoding, and size-limit concerns that are not the same as provider-backed search.
|
||||
|
||||
The model-facing surface should stay stable while backends change. A search provider swap should not change how the model asks for a query, and a fetch implementation swap should not change how the model asks for a URL. Conversely, a provider package should not expose its own model-facing tool schema just because it has extra provider-specific knobs.
|
||||
|
||||
Putting search and fetch directly in `dsh-tool-web` would make the model-facing tool own provider selection, backend request mapping, transport policy, result normalization, prompt guidance, presentation, and schema registration at once. Letting each provider register its own tool has the opposite problem: tool availability, names, descriptions, and parameters would depend on whichever provider packages happen to load, and provider-specific fields would leak into the model contract.
|
||||
|
||||
There is also a provider-selection question. Existing `tool-bash` and `tool-fs` can rely on Cordis `inject` because there is one backend service key. Web has two independent capabilities (`search` and `fetch`) and potentially multiple providers per capability. `inject: ['web']` proves the seam exists; it does not prove a usable search or fetch provider exists, and it does not define which provider should win when several are registered.
|
||||
|
||||
## Proposal
|
||||
|
||||
Introduce web access as a first-class capability seam following [the capability-seam RFC](../../implemented/architecture/2026-06-13-capability-seams.md):
|
||||
|
||||
1. `@deepseek-ai/dsh-web` (`packages/web/web`) owns `ctx.web`, provider registration, provider selection, shared request/result vocabulary, and web-specific errors.
|
||||
2. Provider packages implement concrete backends and register capabilities with `ctx.web`, for example `@deepseek-ai/dsh-web-search-exa`, `@deepseek-ai/dsh-web-search-perplexity`, `@deepseek-ai/dsh-web-search-deepseek`, and `@deepseek-ai/dsh-web-fetch-local`.
|
||||
3. `@deepseek-ai/dsh-tool-web` (`packages/web/tool-web`) owns the model-facing `web_search` and `web_fetch` tool schemas, prompt sections, argument validation, result formatting, and tool-owned presentation over `ctx.web`.
|
||||
|
||||
Providers do not register tools. Providers register capabilities. `dsh-tool-web` is the only owner of model-facing names, descriptions, prompt guidance, JSON schemas, and presentation.
|
||||
|
||||
Search and fetch are separate capabilities and separate model-facing tools, but they are deliberately one seam. `ctx.web` is a single web-access middle layer between provider packages on one side and the tool consumer on the other: one service to inject, one provider-selection policy owner, one abort/error vocabulary, one place a product configures "how this harness reaches the web." The two halves do not share a request schema and have no shared business logic — search normalizes provider-backed discovery into a portable result with optional answer text and citeable sources, while fetch retrieves a concrete public HTTP(S) URL and returns a status code plus bounded decoded content — but they are parallel registries on one capability surface, not two surfaces. The cost is a `WebService` whose registry/status/exec methods come in `Search`/`Fetch` pairs; that parallelism is intentional, not a missed extraction. Splitting into `dsh-search` and `dsh-fetch` is the rejected alternative below.
|
||||
|
||||
`dsh-tool-web` should register model-facing web tools when the product has enabled those tools and the `ctx.web` seam is present. Backend availability is an execution-time concern, not a schema-registration concern:
|
||||
|
||||
- Register `web_search` when web search is enabled for the product/app.
|
||||
- Register `web_fetch` when web fetch is enabled for the product/app.
|
||||
- Do not unregister a tool merely because its selected provider is missing, misconfigured, missing credentials, ambiguous, or temporarily unavailable.
|
||||
- Resolve the provider at execution time, and return a structured `WebError` when the selected capability cannot run.
|
||||
|
||||
This keeps the model schema stable without making plugin load order, credential state, or HMR timing part of the model-facing contract. If web search is enabled but no usable search provider exists, `web_search` remains visible and execution fails with a structured `WebError` such as `WEB_PROVIDER_UNAVAILABLE` or `WEB_PROVIDER_CONFIGURED_UNAVAILABLE`. If a provider appears after `dsh-tool-web`, the next execution can use it without changing the schema. If a provider disappears mid-call, execution fails with a structured `WebError` instead of silently choosing another provider or falling through to `UNKNOWN_TOOL`.
|
||||
|
||||
The first version's provider-change signal is intentionally small. `web/providers-change` has no payload, carries no capability graph, and does not expose provider metadata. It means only "the provider registry changed; observers may recompute status from `ctx.web`." `searchStatus()` and `fetchStatus()` remain derived, not stored, and they are diagnostics plus execution-resolution inputs rather than tool-schema visibility switches.
|
||||
|
||||
## Package topology
|
||||
|
||||
The three-package interface/implementation/consumer split follows bash and filesystem, but the *interface* package is closer to the LLM seam. `LlmService` (`packages/llm/llm/src/index.ts`) is a name-keyed provider registry: `registerAdapter(models, adapter)` stores adapters in a `Map`, returns a disposer, throws `DUPLICATE_ADAPTER` on duplicate keys, and throws `NO_ADAPTER` at resolution time. `ctx.web` follows that registry shape, but has two capability kinds and one small selection-status layer so diagnostics and execution can explain why a search or fetch capability can or cannot run.
|
||||
|
||||
The dependency direction mirrors bash and filesystem:
|
||||
|
||||
```text
|
||||
@deepseek-ai/dsh-tool-web --depends on--> @deepseek-ai/dsh-web <--depends on-- @deepseek-ai/dsh-web-search-exa
|
||||
consumer interface implementation
|
||||
<--depends on-- @deepseek-ai/dsh-web-search-perplexity
|
||||
implementation
|
||||
<--depends on-- @deepseek-ai/dsh-web-search-deepseek
|
||||
implementation
|
||||
<--depends on-- @deepseek-ai/dsh-web-fetch-local
|
||||
implementation
|
||||
```
|
||||
|
||||
At runtime, provider packages register capabilities with `ctx.web`; `tool-web` reads capability status and registers stable tools with `ctx.tools`:
|
||||
|
||||
```mermaid
|
||||
flowchart LR
|
||||
exa["@deepseek-ai/dsh-web-search-exa"] -->|registerSearchProvider| web["@deepseek-ai/dsh-web / ctx.web"]
|
||||
perplexity["@deepseek-ai/dsh-web-search-perplexity"] -->|registerSearchProvider| web
|
||||
deepseek["@deepseek-ai/dsh-web-search-deepseek"] -->|registerSearchProvider| web
|
||||
fetchLocal["@deepseek-ai/dsh-web-fetch-local"] -->|registerFetchProvider| web
|
||||
toolWeb["@deepseek-ai/dsh-tool-web"] -->|searchStatus/fetchStatus| web
|
||||
toolWeb -->|ctx.tools.register| webSearch["tool: web_search"]
|
||||
toolWeb -->|ctx.tools.register| webFetch["tool: web_fetch"]
|
||||
```
|
||||
|
||||
`@deepseek-ai/dsh-web` depends only on Cordis and low-level harness support. It declares `ctx.web`, provider interfaces, request/result types, status types, and error codes. It does not import tool, agent, session, LLM, or provider packages.
|
||||
|
||||
Provider packages depend on `@deepseek-ai/dsh-web` and Cordis. They own credentials, endpoint config, provider-specific request mapping, provider-specific response parsing, and provider-specific error translation into `WebError`. They issue network requests with the platform-native `fetch` (Node 24), mirroring `@deepseek-ai/dsh-llm-deepseek`'s adapter, NOT a cordis HTTP-client service (`ctx.http`/`@cordisjs/plugin-http`) — even where a Perplexity provider's request is shaped like an OpenAI-compatible chat completion, that wire shape is a provider-private detail and does not make the provider depend on `ctx.llm`. A provider does NOT own the `ctx.web` key (two search providers cannot both own it): like `dsh-llm-deepseek`, each provider package is a function/namespace plugin (`inject: ['web']`) whose `apply` constructs the backend and calls `ctx.web.registerSearchProvider` / `registerFetchProvider`. `@deepseek-ai/dsh-web` is the `export default` service that owns the key.
|
||||
|
||||
`@deepseek-ai/dsh-tool-web` depends on `@deepseek-ai/dsh-web`, `@deepseek-ai/dsh-tools`, `@deepseek-ai/dsh-system-prompt`, and Cordis. It never imports concrete provider packages.
|
||||
|
||||
## `ctx.web` contract
|
||||
|
||||
`ctx.web` is a provider registry plus a provider-selecting execution surface. The registry half should stay close to `LlmService`: a `Map<id, provider>` per capability kind, `registerSearchProvider` / `registerFetchProvider` methods that return disposers, duplicate ids that throw `WebError`, and execution-time resolution that throws when the selected provider is absent or unusable. The exact TypeScript signatures belong to the implementation PR, but the seam should expose this shape:
|
||||
|
||||
```ts
|
||||
interface WebSearchProvider {
|
||||
readonly id: string
|
||||
status(): WebProviderStatus
|
||||
search(request: WebSearchRequest, exec?: WebExecContext): Promise<WebSearchResult>
|
||||
}
|
||||
|
||||
interface WebFetchProvider {
|
||||
readonly id: string
|
||||
status(): WebProviderStatus
|
||||
fetch(request: WebFetchRequest, exec?: WebExecContext): Promise<WebFetchResult>
|
||||
}
|
||||
|
||||
interface WebService {
|
||||
registerSearchProvider(provider: WebSearchProvider): () => void
|
||||
registerFetchProvider(provider: WebFetchProvider): () => void
|
||||
|
||||
searchStatus(): WebCapabilityStatus
|
||||
fetchStatus(): WebCapabilityStatus
|
||||
|
||||
search(request: WebSearchRequest, exec?: WebExecContext): Promise<WebSearchResult>
|
||||
fetch(request: WebFetchRequest, exec?: WebExecContext): Promise<WebFetchResult>
|
||||
}
|
||||
|
||||
interface WebExecContext {
|
||||
readonly signal?: AbortSignal
|
||||
}
|
||||
```
|
||||
|
||||
`WebExecContext` is execution control, not business input. The first version should carry only `signal` so `tool-web` can propagate turn cancellation, tool timeout, and agent disposal into provider network requests, SSE readers, and expensive decoding. It should not pass `ToolExecution` through the seam, because that would make `dsh-web` depend on `dsh-tools`.
|
||||
|
||||
`@deepseek-ai/dsh-web` should also declare a Cordis event named `web/providers-change`. Provider ids are stable strings and unique within their capability kind. Registering a duplicate search provider id or duplicate fetch provider id should fail rather than silently replace the old provider. Provider registration returns a disposer, emits `web/providers-change` after successful registration, and emits it again when the provider is disposed. The registry should follow the existing `ctx.tools.register()` / `ctx.systemPrompt.section()` pattern: wrap the mutation in `ctx.effect()`, install the rollback disposer before emitting `web/providers-change`, and let a throwing registration-time change listener roll back the just-added provider instead of leaking it into the registry.
|
||||
|
||||
## Provider status and selection
|
||||
|
||||
Provider status and capability selection are separate concepts, but both stay minimal. A provider reports only whether that concrete implementation is usable by cheap local checks such as credential presence or parseable endpoint config. A provider `status()` must not make network calls. The service reports whether the capability has a selected usable provider, or why execution would fail.
|
||||
|
||||
`LlmService` has no status type at all: availability is expressed as registry membership plus a resolution-time throw. `ctx.web` needs a small status answer because product apps, diagnostics, tests, and execution can report precise provider-selection failures without probing individual providers from the tool layer. Status must be derived from the configured provider id, registered providers, and each provider's cheap local `status()` on each call; it must not be stored as mutable service state.
|
||||
|
||||
`WebCapabilityStatus` stays intentionally small: `available` plus a `reason` discriminant, and the selected `providerId` on the available branch so diagnostics can report which provider won. It does NOT carry the per-reason payload (the unavailable provider id, the ambiguous candidate set, the underlying provider-unavailable reason). That branchable detail lives in the structured `WebError` thrown at execution time, which is the surface callers route on; duplicating it into the status union would give the same fact two homes that can disagree. `searchStatus()` / `fetchStatus()` answer "can this capability run, and if not, in which broad category does it fail" — enough for startup diagnostics and the execution-resolution decision — and the thrown error answers "exactly which provider/ids/reason."
|
||||
|
||||
`WebProviderStatus` is an input to selection, not a health system. `tool-web` reads only the aggregated `searchStatus()` / `fetchStatus()`, never each provider's `status()` directly, so selection policy has one owner.
|
||||
|
||||
```ts
|
||||
type WebProviderStatus =
|
||||
| { readonly available: true }
|
||||
| { readonly available: false; readonly reason: 'missing-credential' | 'misconfigured' }
|
||||
|
||||
type WebCapabilityStatus =
|
||||
| { readonly available: true; readonly providerId: string }
|
||||
| { readonly available: false; readonly reason: 'none' | 'configured-missing' | 'configured-unavailable' | 'ambiguous' }
|
||||
```
|
||||
|
||||
Selection must not depend on registration order. Cordis load order, config ordering, and HMR timing are not product semantics.
|
||||
|
||||
| Situation | Status / behavior |
|
||||
|---|---|
|
||||
| A configured provider id is registered and `status().available === true` | `available: true` for that provider |
|
||||
| A configured provider id is not registered | `configured-missing`; execution fails with `WEB_PROVIDER_CONFIGURED_MISSING` |
|
||||
| A configured provider id is registered but unavailable | `configured-unavailable`; execution fails with `WEB_PROVIDER_CONFIGURED_UNAVAILABLE` |
|
||||
| No provider id is configured and exactly one provider for that kind is registered and available | `available: true` for that single provider |
|
||||
| No provider id is configured and no provider for that kind is registered | `none`; execution fails with `WEB_PROVIDER_UNAVAILABLE` |
|
||||
| No provider id is configured and multiple usable providers for that kind are registered | `ambiguous`; execution fails with `WEB_PROVIDER_AMBIGUOUS` rather than choosing by registration order |
|
||||
| No provider id is configured and providers exist but none are usable | `none`; execution fails with `WEB_PROVIDER_UNAVAILABLE` |
|
||||
|
||||
The "single provider auto-selects" rule is for tests, demos, and simple deployments. Product configs should set explicit provider ids:
|
||||
|
||||
```yaml
|
||||
- id: web
|
||||
name: '@deepseek-ai/dsh-web'
|
||||
config:
|
||||
searchProvider: exa
|
||||
fetchProvider: local-http
|
||||
|
||||
- id: web-search-exa
|
||||
name: '@deepseek-ai/dsh-web-search-exa'
|
||||
|
||||
- id: web-search-perplexity
|
||||
name: '@deepseek-ai/dsh-web-search-perplexity'
|
||||
|
||||
- id: web-search-deepseek
|
||||
name: '@deepseek-ai/dsh-web-search-deepseek'
|
||||
|
||||
- id: web-fetch-local
|
||||
name: '@deepseek-ai/dsh-web-fetch-local'
|
||||
|
||||
- id: tool-web
|
||||
name: '@deepseek-ai/dsh-tool-web'
|
||||
```
|
||||
|
||||
Operational overrides such as environment variables may exist, but they must feed the same explicit selection path. For example, `DSH_WEB_SEARCH_PROVIDER=perplexity` is equivalent to config `searchProvider: perplexity`; it is not a hidden priority chain inside `dsh-tool-web`.
|
||||
|
||||
`ctx.web.search()` and `ctx.web.fetch()` resolve the provider at execution time using the same rules as the status query. If the selected capability is unavailable, they throw `WebError` with a structured code such as `WEB_PROVIDER_UNAVAILABLE`, `WEB_PROVIDER_CONFIGURED_MISSING`, `WEB_PROVIDER_CONFIGURED_UNAVAILABLE`, or `WEB_PROVIDER_AMBIGUOUS`. If no provider is explicitly configured and no usable provider exists, the status and execution error are both the generic `none` / `WEB_PROVIDER_UNAVAILABLE` case; the first version should not add a diagnostic summary of every unavailable provider.
|
||||
|
||||
## Search request and result schema
|
||||
|
||||
The first `web_search` model-facing tool should be small. The only model-facing argument is:
|
||||
|
||||
- `query`: required string.
|
||||
|
||||
`max_results` is NOT exposed to the model in the first version. It is a `dsh-tool-web`-layer decision: the tool sets the result bound — a default of `8` (aligning with OpenCode's Exa default), as an exported constant mirroring `dsh-tool-fs`'s `READ_LIMIT` / `GREP_LIMIT` — and passes it to the seam as `maxResults` on the `WebSearchRequest`. Keeping it off the model schema means the model just asks a question and the product controls how much context comes back; the field can be promoted to a model-facing argument later without breaking the seam.
|
||||
|
||||
`maxResults` flows tool → seam → provider, and the bound is enforced on the way back:
|
||||
|
||||
- `dsh-tool-web` owns the value and puts it on `WebSearchRequest.maxResults`.
|
||||
- `ctx.web` passes the request through to the selected provider unchanged.
|
||||
- A provider should apply `maxResults` at the request layer when its API supports it (Exa's `numResults`), as a cost/latency optimization.
|
||||
- `ctx.web` enforces the bound on the result: if a provider returns more than `maxResults` sources — because its API has no result-count control (Perplexity) or ignored the hint — the seam truncates `sources[]` to `maxResults` and sets `WebSearchResult.truncated` to `true` before returning. This makes the bound a single cross-provider guarantee the model-facing layer can rely on, rather than something each provider must remember to honor.
|
||||
|
||||
The seam request should not include provider-specific controls such as Perplexity model selection, search recency, domain filters, Exa `livecrawl`, Exa `type`, regional hints, generated-answer budgets, or search depth in the first version. Those fields should be added only when they have provider-neutral semantics that both the tool schema and selected providers can honor honestly.
|
||||
|
||||
```ts
|
||||
interface WebSearchRequest {
|
||||
readonly query: string
|
||||
/** Upper bound on returned sources; the seam truncates to it. Omitted = no bound. `dsh-tool-web` always sets it. */
|
||||
readonly maxResults?: number
|
||||
}
|
||||
|
||||
interface WebSearchResult {
|
||||
readonly providerId: string
|
||||
readonly query: string
|
||||
readonly content?: string
|
||||
readonly sources: readonly WebSearchSource[]
|
||||
readonly truncated: boolean
|
||||
}
|
||||
|
||||
interface WebSearchSource {
|
||||
readonly url: string
|
||||
readonly title?: string
|
||||
readonly snippet?: string
|
||||
readonly publishedAt?: string
|
||||
}
|
||||
```
|
||||
|
||||
`content` is optional provider-generated answer text, search context, or summary. `sources[]` is the portable citation surface. A source always has a URL; title, snippet, and `publishedAt` are optional because not every provider returns them. `title` should not be required: Perplexity-style citations may provide only URLs, and forcing adapters to invent titles would make the seam lie. `dsh-tool-web` can render `title ?? hostname(url)` for display. `publishedAt` is an optional publication/crawl timestamp as an ISO-8601 string — Exa returns it as `publishedDate` on each result and Perplexity returns a `date` on search results, so it is real provider data, not derived; the seam carries it as a string and leaves date parsing to the consumer.
|
||||
|
||||
Exa search should map each entry of the provider's flat `results[]` into a `WebSearchSource`: `url` ← `url`, `title` ← `title`, `snippet` ← the first `highlights[]` entry (an entry with no highlight has no portable snippet and is dropped), `publishedAt` ← `publishedDate`. Exa returns no provider-generated answer, so `content` is omitted. Perplexity search should map `choices[0].message.content` to `content` and prefer the structured top-level `search_results[]` for `sources[]` — `url` ← `url`, `title` ← `title`, `snippet` ← `snippet` (often empty), `publishedAt` ← `date` — falling back to the URL-only `citations[]` array only when `search_results` is absent (those sources carry just a `url`). If a provider returns fewer structured fields than the seam supports, the adapter omits those optional fields.
|
||||
|
||||
Full page retrieval remains the job of `web_fetch(url)`. Search snippets are discovery context, not fetched page bodies.
|
||||
|
||||
## Fetch request and result schema
|
||||
|
||||
The first `web_fetch` implementation should be an anonymous public HTTP(S) fetch provider, likely `local-http`. It should fetch bytes from a concrete URL, apply the basic transport hygiene below (http/https-only, credential rejection, byte/time caps, cross-origin redirect blocking), decode textual content, and return only the minimal model-useful result: final URL, status code, body, and truncation. It should not carry browser cookies, editor credentials, git credentials, internal auth tokens, or implicit access to private services. (Full SSRF / private-network blocking is deferred — see [Deferred work](#deferred-work).)
|
||||
|
||||
The first seam request should stay smaller than OpenCode's model-facing tool:
|
||||
|
||||
- `url`: required HTTP(S) URL.
|
||||
- `timeoutMs`: optional positive number capped by the provider.
|
||||
|
||||
The seam request deliberately does not include `format`, `prompt`, or provider-specific extraction controls. `format` is a presentation decision over a fetched resource; `prompt` is a higher-level LLM summarization instruction; extraction APIs such as Firecrawl, Exa, Tavily, or Parallel may not expose a concrete HTTP response. If the product later needs provider-backed page extraction, add a separate `web_extract` capability or explicitly widen this RFC before implementation. Do not smuggle extract semantics into `web_fetch` by making every HTTP field optional.
|
||||
|
||||
HTTP status is part of the fetched resource state, not automatically a tool failure. A successful network fetch of a `404` or `500` response should return `WebFetchResult` with the status code and a bounded decoded body when the content type is supported. `WebError` is for failures to safely retrieve or represent the resource: invalid or blocked URL, redirect policy violation, timeout, abort, response too large, unsupported content type, provider failure, or network failure.
|
||||
|
||||
```ts
|
||||
interface WebFetchRequest {
|
||||
readonly url: string
|
||||
readonly timeoutMs?: number
|
||||
}
|
||||
|
||||
interface WebFetchResult {
|
||||
readonly providerId: string
|
||||
readonly url: string
|
||||
readonly statusCode: number
|
||||
readonly body: WebFetchBody
|
||||
readonly truncated: boolean
|
||||
}
|
||||
|
||||
type WebFetchBody =
|
||||
| { readonly kind: 'html'; readonly content: string }
|
||||
| { readonly kind: 'text'; readonly content: string }
|
||||
```
|
||||
|
||||
`WebFetchResult.url` is the final URL after allowed redirects. The request URL is already present in `WebFetchRequest`, so the first version should not add separate `requestedUrl` and `finalUrl` fields.
|
||||
|
||||
`WebFetchBody` is a CLOSED discriminated union owned by `dsh-web`, not a merge-extensible map. The merge-extensible pattern (`ContentBlockMap`) exists for variants that independent plugins introduce and the seam cannot foresee; body kinds are not that — `dsh-web` declares the kind, the fetch provider decodes it, and `dsh-tool-web` renders it, so a new kind is a coordinated change across three known packages, not a plugin extension. Keeping it closed buys compile-time exhaustiveness: consumers `switch` on `kind` ending in `default: assertNever(body, …)`, so adding a kind breaks compilation at every consumer that must render it (e.g. `tool-web`'s `html`→markdown vs `text` passthrough) until that arm is written. Each arm stays its own object literal even when the fields coincide today, leaving room for arm-specific fields (a future `pdf` body's `pageCount`, a `json` body's parsed value) without reshaping the type. Since the harness is unreleased, extending this closed union later is free (no migration, no compat shim).
|
||||
|
||||
The provider owns safe resource retrieval: URL validation, HTTP transport, redirect policy, timeout, abort propagation, byte caps, charset decoding, content-type classification, and binary rejection. `dsh-tool-web` owns presentation: HTML-to-markdown, HTML-to-text, truncation formatting for the model, and future summaries.
|
||||
|
||||
The fetch provider must define resource controls before the tool ships:
|
||||
|
||||
- Accept only `http:` and `https:` URLs.
|
||||
- Reject credentials in URLs.
|
||||
- Enforce maximum URL length, response byte cap, decoded body character cap, timeout, and redirect hop cap.
|
||||
- Propagate abort signals through network fetches and expensive decoding.
|
||||
- Automatically follow only same-origin redirects.
|
||||
- Fail cross-origin redirects with `WEB_REDIRECT_BLOCKED`, requiring a fresh tool call and therefore a fresh provider/permission decision. (Claude Code's WebFetch uses this same model — it does not auto-follow a cross-host redirect; it returns the redirect target to the model for a fresh call.)
|
||||
- Use an explicit product user agent rather than silently impersonating a browser by default.
|
||||
|
||||
SSRF / private-network protection (blocking private, loopback, link-local, multicast, and otherwise non-public destinations, with DNS-resolve-then-validate to defeat rebinding and per-hop re-validation on redirects) is **deferred** — see [Deferred work](#deferred-work). Until it lands, `web_fetch` is an SSRF primitive and must not be enabled in a deployment that can reach sensitive internal network targets.
|
||||
|
||||
## Tool consumer behavior
|
||||
|
||||
`dsh-tool-web` owns two `ToolDefinition`s: `web_search` and `web_fetch`. It owns model-facing JSON schemas, snake_case argument names, prompt sections, result rendering to `ContentBlock[]`, `presentCall`, and `presentResult`.
|
||||
|
||||
`dsh-tool-web` must not enumerate providers or call provider `status()` directly. Its execution path is `ctx.web.search()` / `ctx.web.fetch()`, and any optional startup diagnostics should read only `ctx.web.searchStatus()` / `ctx.web.fetchStatus()`. That keeps provider selection in one layer; otherwise the tool package could decide one provider is usable while execution resolves a different state.
|
||||
|
||||
Tool registration in the first version is a minimal stable sync:
|
||||
|
||||
1. On plugin startup, read the `dsh-tool-web` `Config` (`search?: boolean`, `fetch?: boolean`, both default `true`) that enables or disables each web tool.
|
||||
2. If web search is enabled, register `web_search` (its disposer is fiber-scoped via the effect-based registry).
|
||||
3. If web fetch is enabled, register `web_fetch` (likewise fiber-scoped).
|
||||
4. Do not dispose either tool merely because `ctx.web.searchStatus()` or `ctx.web.fetchStatus()` is unavailable.
|
||||
5. Disposing the `tool-web` fiber tears down its registrations automatically.
|
||||
|
||||
Provider status changes affect execution results and diagnostics, not whether the model-facing schema exists. If a product wants no web tools at all, it disables `dsh-tool-web` or the individual web tool in config; if it wants web tools but the backend is misconfigured, the model sees a structured tool error at execution time.
|
||||
|
||||
Prompt guidance should explain the semantic split: use `web_search` for discovery and current information, then use `web_fetch` when the model needs the content of a specific URL. The prompt and tool result should tell the model to cite relevant URLs with markdown links.
|
||||
|
||||
The model-facing output should be text-first because current tool results are `ContentBlock[]`, but the seam outcome should stay structured so UI presentation and future adapters do not have to scrape rendered text.
|
||||
|
||||
## Errors
|
||||
|
||||
`dsh-web` should define `WebError extends HarnessError` with stable codes. Initial codes should include only states that callers may reasonably branch on:
|
||||
|
||||
- `WEB_PROVIDER_UNAVAILABLE`
|
||||
- `WEB_PROVIDER_CONFIGURED_MISSING`
|
||||
- `WEB_PROVIDER_CONFIGURED_UNAVAILABLE`
|
||||
- `WEB_PROVIDER_AMBIGUOUS`
|
||||
- `WEB_DUPLICATE_PROVIDER`
|
||||
- `WEB_INVALID_URL`
|
||||
- `WEB_BLOCKED_URL`
|
||||
- `WEB_REDIRECT_BLOCKED`
|
||||
- `WEB_FETCH_TOO_LARGE`
|
||||
- `WEB_FETCH_TIMEOUT`
|
||||
- `WEB_ABORTED`
|
||||
- `WEB_UNSUPPORTED_CONTENT_TYPE`
|
||||
- `WEB_PROVIDER_ERROR`
|
||||
|
||||
`WEB_DUPLICATE_PROVIDER` is thrown synchronously from `registerSearchProvider` / `registerFetchProvider` when an id is already registered for that capability kind (the analogue of `LlmService`'s `DUPLICATE_ADAPTER`); it is a registration-time programming error, not an execution outcome, but shares the `WebError` code space so callers see one taxonomy. `WEB_PROVIDER_ERROR` is the catch-all for a provider's own failure surfaced through the seam, including network/transport failure in `web-fetch-local` (DNS, connection refused, TLS); the first version does not split out a separate `WEB_NETWORK` code, but the provider should set a descriptive message so the model and logs can tell a network failure from a provider API failure.
|
||||
|
||||
Tool execution should let these errors flow through `ToolRegistry.execute()`, which already converts `HarnessError` into an error tool result with structured metadata. The model gets a readable error message; hooks, tests, and UI code can route on the stable code.
|
||||
|
||||
## Tests
|
||||
|
||||
Tests should prove the seam contract without turning this RFC into an implementation checklist.
|
||||
|
||||
`dsh-web` tests cover provider registration and disposal, duplicate provider ids, `web/providers-change` emission, rollback when a registration-time `web/providers-change` listener throws, `searchStatus()` and `fetchStatus()` for the selection table above, execution-time provider resolution, `maxResults` truncation of `sources[]` with `truncated` set when a provider over-returns, abort propagation through `WebExecContext.signal`, and structured `WebError` codes.
|
||||
|
||||
Search provider tests cover request mapping, response parsing into `content` plus `sources[]`, missing credentials, provider errors, timeout/abort, truncation, and a self-skipping with-key smoke test for each real provider. Perplexity fixtures must include URL-only citations so the optional source fields stay honest.
|
||||
|
||||
`dsh-web-fetch-local` tests cover real HTTP behavior using a local test server: valid text and HTML fetches, non-2xx HTTP responses returned as results, byte/decoded-body caps, timeout, abort, invalid URLs, credential-in-URL rejection, cross-origin redirect blocking, unsupported content types, and product user agent. (Private-destination/SSRF blocking tests come with that deferred work.)
|
||||
|
||||
`dsh-tool-web` tests execute through the real tool registry. They verify schema registration follows product/app tool enablement rather than provider availability, unavailable or ambiguous providers produce structured execution errors, argument validation, formatting of successful search/fetch results, structured error propagation, and cleanup on disposal.
|
||||
|
||||
Integration tests should load the real seam, provider, and tool packages together and execute through `ctx.tools.execute()` rather than calling providers directly. If wiring the tools into an ACP-facing example changes editor-visible transcripts, add or update the relevant snapshot scenario in the same change.
|
||||
|
||||
At least one test must drive these packages through their REAL cordis Loader/export path, not a hand-built `ctx.plugin({...})` mount, so a broken export shape is caught (see [docs/postmortem/0001](../../../postmortem/0001-acp-default-export-drops-inject.md) and `packages/AGENTS.md` § plugin-export-shape). The two shapes need different guards: `dsh-web` is a **service** (`export default` the class) and a stray extra export would surface as a missing service; the provider packages and `dsh-tool-web` are **namespace plugins** (named `name`/`inject`/`apply`, NO default), and because each has `inject`, a stray `export default apply` makes `unwrapExports` drop the `inject` and the plugin throws `cannot get property … without inject` the moment it loads — so a Loader smoke that boots tool-web over `ctx.web` catches it (and each provider's registration test mounts it the real way and asserts no default export). Prove the guard bites: add `export default apply` to `tool-web`, watch the smoke go red, revert.
|
||||
|
||||
## Migration plan
|
||||
|
||||
This is new capability work, so no compatibility migration is required while the harness is unreleased.
|
||||
|
||||
Land the work in seam order:
|
||||
|
||||
1. Add `packages/web/web` with `ctx.web`, provider registration, provider status, capability status, selection, request/result/error types, and contract tests.
|
||||
2. Add `packages/web/web-search-exa` with parser/unit tests and a self-skipping real-provider smoke test.
|
||||
3. Add `packages/web/web-search-perplexity` with parser/unit tests and a self-skipping real-provider smoke test.
|
||||
4. Add `packages/web/web-search-deepseek` with parser/unit tests and a self-skipping real-provider smoke test.
|
||||
5. Add `packages/web/web-fetch-local` with local HTTP behavior tests.
|
||||
6. Add `packages/web/tool-web` with config-driven tool registration, prompt sections, model formatting, presentation, and tool-registry tests.
|
||||
7. Wire product app/example configs only after package behavior is stable, because tool schemas and prompt sections affect agent behavior and snapshots.
|
||||
8. Update `docs/architecture.md`, `packages/README.md`, package READMEs, generated Cordis catalogs if new events/services are added, and maintenance scripts.
|
||||
|
||||
## Alternatives considered
|
||||
|
||||
### Let each provider register its own model-facing tool
|
||||
|
||||
This matches the most flexible provider-plugin systems: every provider can expose its full native schema. It is rejected for the harness because it gives provider packages ownership of model-facing names, descriptions, prompt guidance, and result formatting. Multiple search providers would produce duplicate tool names or provider-specific tool names, and the model would learn backend details instead of a stable product capability.
|
||||
|
||||
### Put provider dispatch directly in `dsh-tool-web`
|
||||
|
||||
This resembles OpenCode's local web search: one stable `websearch` tool dispatches to Exa or Parallel internally. It is acceptable for a small product path but wrong as a harness foundation. The tool package would own provider selection, credentials, request mapping, transport, response parsing, and presentation, making it hard to add Exa and Perplexity without baking their differences into the tool schema.
|
||||
|
||||
### Split search and fetch into two seams (`dsh-search`, `dsh-fetch`)
|
||||
|
||||
Tempting because the two halves share no request schema and no business logic, so each would map cleanly onto the bash/fs three-package template, and the `Search`/`Fetch` method-pair duplication on `WebService` would disappear. Rejected because the shared machinery — provider-id registry, registration-order-independent selection policy, abort propagation, the `WebError` taxonomy, and the product-facing "how this harness reaches the web" config surface — is real and would otherwise be duplicated across two near-identical seams. One `ctx.web` middle layer gives the product a single thing to inject and configure and gives provider selection one owner. The price is the parallel `searchX`/`fetchX` method pairs, which is accepted deliberately.
|
||||
|
||||
### Choose the first registered provider
|
||||
|
||||
Rejected. Registration order is not a product policy. It can change with config order, plugin loading, HMR, or refactors. Provider selection must be explicit, or automatic only when exactly one usable provider exists.
|
||||
|
||||
### Treat Firecrawl/Exa/Tavily/Parallel extraction as fetch
|
||||
|
||||
Rejected for the first version. Those providers often return extracted or summarized content rather than a concrete HTTP response. If the product needs extraction, design `web_extract` or deliberately widen the fetch seam later.
|
||||
|
||||
### Mirror Claude Code's `url + prompt` WebFetch shape
|
||||
|
||||
Rejected for the seam. `prompt` turns fetch into LLM summarization and couples public-web retrieval to a model provider. The harness seam should fetch and decode deterministically; `dsh-tool-web` can later offer summaries as a presentation mode without making `ctx.web` depend on `ctx.llm`.
|
||||
|
||||
## Risks
|
||||
|
||||
**The search schema may be too thin.** Exa and Perplexity both expose useful provider-specific controls. The first version should resist adding them until they can be defined provider-neutrally and enforced honestly by both tool registration and provider execution.
|
||||
|
||||
**Perplexity citations may be sparse.** A citation may be only a URL. Making `title` and `snippet` optional keeps the seam truthful but means `tool-web` must render useful fallback labels.
|
||||
|
||||
**Stable tool registration can defer misconfiguration to execution.** Keeping the tool visible is correct when the product enabled web access, but product apps that expect web search should surface `configured-missing`, `configured-unavailable`, and `ambiguous` loudly during startup diagnostics so users do not discover setup problems only after the model calls the tool.
|
||||
|
||||
**Provider state can change after startup.** A tool can be visible in the request assembled at step start and lose its provider before execution. The execution path must resolve again and fail with a structured error.
|
||||
|
||||
**Fetch is a network boundary, not just a read-only tool.** `web_fetch` can still reach sensitive network targets or exfiltrate data through URLs. The first version ships only the basic transport hygiene (http/https-only, credential rejection, byte/time caps, cross-origin redirect blocking); SSRF / private-network blocking is deferred (see [Deferred work](#deferred-work)), so until it lands `web_fetch` must not be enabled where it can reach internal targets.
|
||||
|
||||
**Large web content can damage context quality.** Providers must enforce byte/character caps and report `truncated`; `tool-web` must format bounded model output with clear continuation or follow-up guidance.
|
||||
|
||||
## Deferred work
|
||||
|
||||
- SSRF / private-network protection for `web_fetch`: block private, loopback, link-local, multicast, and otherwise non-public destinations so `web_fetch` is not an SSRF primitive. Doing it correctly is more than a URL-string check — it needs DNS-resolve-then-connect-to-the-validated-IP (to defeat DNS rebinding / TOCTOU), per-hop re-validation across redirects, and IPv6 edge handling (private ranges, IPv4-mapped addresses). Neither reference implementation surveyed does IP-level blocking (OpenCode does a prefix check then fetches; Claude Code relies on a centralized hostname blocklist plus a "private URLs will fail" prompt), so there is no implementation to copy and this is the harness's only SSRF defense — it warrants its own focused design/spike. Until it lands, `web_fetch` must only be enabled in deployments that cannot reach sensitive internal targets.
|
||||
- A `pdf` `WebFetchBody` kind: the `local-http` provider decodes text-extractable PDFs (best-effort, capped, `truncated`) into a `{ kind: 'pdf'; content; pageCount? }` arm, and `tool-web` renders it. This is fetch, not `web_extract` — PDF retrieval is a concrete HTTP 200 plus deterministic local decoding, not provider-side extraction of a non-HTTP resource. Adding it is a coordinated change across `dsh-web` (declare the arm), the provider (decode + narrow "binary rejection" to "reject binary except text-extractable PDF"; scanned/image PDFs needing OCR stay out of scope), and `tool-web` (render). The closed `WebFetchBody` union makes the consumer side fail to compile until the new arm is handled.
|
||||
- Provider-backed extraction as a separate `web_extract` capability, rather than widening `web_fetch` silently.
|
||||
- Permission policy integration once the deferred permission system lands.
|
||||
- Provider-neutral search controls beyond `query` and `maxResults`, once Exa and Perplexity can both honor them honestly.
|
||||
|
||||
## Open questions
|
||||
|
||||
- Should product app packages treat `configured-missing`, `configured-unavailable`, and `ambiguous` as fatal startup errors when web is explicitly configured, or should `dsh-web` only report status and let apps decide?
|
||||
- Where should permission policy for public web access live once the deferred permission system lands: a dedicated web permission plugin on `tools/execute`, provider config, or both?
|
||||
@@ -0,0 +1,175 @@
|
||||
# RFC: Make `dsh-fs-policy` an event-gate plugin, not a method interface
|
||||
|
||||
Status: implemented
|
||||
|
||||
## Problem
|
||||
|
||||
[The split-fs-seam RFC](../simplification/2026-06-26-fsspec-style-fs-seam.md) put `ctx.fileContext` between the model-facing tools and the `ctx.fs` provider: `dsh-tool-fs` injects `fileContext` and routes every `read`/`write`/`edit` through its methods. That makes `fileContext` **in-path and mandatory**. The tool cannot reach `ctx.fs` without it, the policy layer owns the fs I/O and the read windowing, and a deployment that does not want observed-state policy cannot simply drop the package — `dsh-tool-fs` would fail to resolve `ctx.fileContext`.
|
||||
|
||||
This couples three things that should be separable:
|
||||
|
||||
1. **What the tool does** — resolve a path, read a window, write/edit a file. This is the tool's job and needs only `ctx.fs`.
|
||||
2. **The freshness/observation policy** — "edit requires a prior read", "write/edit must be based on the version you read". This is the `dsh-fs-policy` plugin's job.
|
||||
3. **The recording of observed state** — a side effect that should never block the tool from functioning.
|
||||
|
||||
Because the tool calls `fileContext` methods, removing the policy layer is a breaking change rather than a graceful loss of an *add-on*. The policy is load-bearing for the tool to even run, not an opt-in tightening.
|
||||
|
||||
## Decision
|
||||
|
||||
Invert the control flow. **`dsh-tool-fs` becomes the executor and calls `ctx.fs` directly**; **`dsh-fs-policy` becomes a gate + recorder plugin** that participates through events, never through a method the tool calls and never by registering a `ctx.fileContext` service.
|
||||
|
||||
```text
|
||||
tool dsh-tool-fs executor: resolves, reads windows, writes/edits via ctx.fs;
|
||||
emits fs policy events; renders results
|
||||
policy dsh-fs-policy plugin: listens to fs/write-intent +
|
||||
fs/edit-intent (single-slot waterfall) and fs/observed
|
||||
(emit) events; adds observed-state + freshness.
|
||||
provider seam dsh-fs ctx.fs: text IO + ATOMIC mutation primitives whose version
|
||||
guard is OPTIONAL; owns the fs policy event vocabulary
|
||||
provider dsh-fs-local local implementation of ctx.fs
|
||||
```
|
||||
|
||||
The model is **additive, not subtractive**: `ctx.fs` on its own is a complete, unconstrained text-storage seam — `read` reads, `write` unconditionally creates-or-overwrites, `edit` unconditionally replaces literal text in the current content. There is no "先读后写", no version check, nothing to remove; the bare provider just does the I/O atomically. `dsh-fs-policy` is a plugin that *adds* constraints on top: observed-state, read-before-edit, and "write/edit must be based on the version you read". So removing `dsh-fs-policy` does not break `dsh-tool-fs` at the service-injection boundary; it removes the policy gate and leaves the bare provider behavior. The intended deployment stance is that a config loading the fs tools also loads `dsh-fs-policy`, so the user-facing behavior and prompt discipline are read-before-write/edit (the `coding-agent` and `acp-agent` demos wire the full stack). The bare-provider mode exists because the tool should not be method-coupled to the policy plugin, not because an unconstrained filesystem is the normal product stance.
|
||||
|
||||
`dsh-tool-fs` no longer injects `fileContext`. It injects `fs` and `tools`/`systemPrompt`.
|
||||
|
||||
## The policy is enforced by provider CAS, not by `dsh-fs-policy` stat
|
||||
|
||||
`dsh-fs-policy` enforces "you must write/edit based on the version you read" **without ever calling `stat` or comparing versions itself**. It supplies the observed version as the CAS basis and lets the provider's mutation critical section detect staleness:
|
||||
|
||||
- "Have you read this file?" is the one thing `dsh-fs-policy` decides locally — a `WeakMap` lookup, no I/O. No record ⇒ `FS_NOT_OBSERVED`.
|
||||
- "Is the version you read still current?" is decided **inside `ctx.fs.editText`/`writeText`**, in the same atomic lock that performs the read-match-rename. `dsh-fs-policy` passes `vObserved` as the expectation; the provider raises `FS_STALE_VERSION` if the file has moved on.
|
||||
|
||||
This is deliberate. If `dsh-fs-policy` stat-ed and compared versions in its waterfall handler, there would be a TOCTOU gap between that check and the tool's actual write — the file could change in between, so the check would be a false guarantee that the provider's lock has to back up anyway. Putting the version check in the provider's critical section is both race-free and zero extra `stat`. So `dsh-fs-policy` does **no** filesystem I/O; the "must be based on the latest read" guarantee is *realized* by CAS, and `dsh-fs-policy` only chooses the basis (`vObserved`) and gates on prior observation.
|
||||
|
||||
## Provider contract change: the version guard is optional
|
||||
|
||||
For the bare provider to be unconstrained, the version guard on its two mutations becomes **optional** — present ⇒ guarded, absent ⇒ unconditional:
|
||||
|
||||
```ts ignore-check
|
||||
// writeText: expected is now optional. The FsWriteIntent union is UNCHANGED.
|
||||
writeText(target: FsTarget, content: string, expected?: FsWriteIntent, signal?: AbortSignal): Promise<FsWriteOutcome>
|
||||
// undefined → unconditionally create-or-overwrite (bare default)
|
||||
// createIfAbsent → create only, reject an existing file (dsh-fs-policy, unobserved) [unchanged]
|
||||
// replaceIfVersion → overwrite only at the observed version, else FS_STALE_VERSION [unchanged]
|
||||
|
||||
// editText: expected becomes optional (was the required { version: FsVersion }).
|
||||
editText(target: FsTarget, edit: FsEditRequest, expected?: { version: FsVersion }, signal?: AbortSignal): Promise<FsEditOutcome>
|
||||
// undefined → unconditionally replace literal text in the current content (bare default);
|
||||
// a missing target still reports FS_STALE_VERSION
|
||||
// { version } → edit only at that version, else FS_STALE_VERSION (the current behavior)
|
||||
```
|
||||
|
||||
The `FsWriteIntent` union itself does not change — the third "unconditional" state is expressed by *omitting* `expected`, so both mutations share one symmetric shape (`expected?`: omit = no guard, present = guarded). This keeps full backward compatibility for the guarded paths `dsh-fs-policy` uses; only the previously-impossible "no guard" case is new, and it is the bare-provider default. The mutation still runs inside the backend's per-target lock either way, so an unconditional write/edit is still atomic (no torn files); "unconditional" drops the *version* precondition, not the atomicity. `editText` reports a missing target as `FS_STALE_VERSION` on both guarded and unguarded paths, preserving one edit failure code for "the target cannot be edited at this moment".
|
||||
|
||||
## Event vocabulary (owned by `dsh-fs`)
|
||||
|
||||
The events live in `@deepseek-ai/dsh-fs`, not in `dsh-fs-policy`. This is forced by the decoupling contract: `dsh-tool-fs` is the emitter, so it must reference the event types, and it must keep compiling even though `dsh-fs-policy` no longer provides a method service. `dsh-fs` is the package both `dsh-tool-fs` and `dsh-fs-policy` already depend on, so it is the only home that lets the emitter and the policy listener share a vocabulary without the emitter depending on the policy plugin.
|
||||
|
||||
These events carry existing `dsh-fs` vocabulary (`FsTarget`, `FsVersion`, `FsWriteIntent`) plus an opaque actor — not model-facing concepts (no line windows, numbered lines, or rendered footers leak down).
|
||||
|
||||
**The two `fs/*` decision events are single-slot decision points, NOT a composable interception chain.** A waterfall listener that does not call `next()` short-circuits the rest of the chain (verified in [vendor/cordis/src/events.ts](../../../../vendor/cordis/src/events.ts) — `waterfall` runs listeners around the final `next` thunk, and a listener that returns without calling `next()` reaches neither later listeners nor the tool's default thunk). `dsh-fs-policy` fully decides the write/edit expectation and does not call `next()`, so it occupies that one decision slot in the default deployment. This is deliberate: "what version basis does this mutation guard against" is a single decision, not an accumulation. The names (`fs/write-intent`, `fs/edit-intent`) say "produce the value", not "authorize", so they do not imply a stackable authorization chain. Genuinely composable interception (permission, audit, sandbox) belongs on the existing `tools/execute` waterfall, which every tool call already flows through — not on this fs version-decision slot.
|
||||
|
||||
**The occupant is decided by registration order — first-registered (or `prepend`ed) wins.** cordis dispatches waterfall listeners in registration order (`push`, or `unshift` for `prepend` — [vendor/cordis/src/events.ts](../../../../vendor/cordis/src/events.ts)), and the first non-`next()` decider short-circuits the rest. So the slot is **first-wins**, and `dsh-fs-policy` owning it rests on the default deployment convention: it is the decider registered for these events. The event shape does NOT itself guarantee "an unread edit is rejected" — a plugin that registers a looser `fs/edit-intent` decider BEFORE `dsh-fs-policy` (or with `prepend`) would decide first and bypass the `FS_NOT_OBSERVED` gate. That is the inherent property of a first-wins single slot, stated here so it is not mistaken for an enforced invariant. This RFC does not add a multi-policy composition mechanism; the implementation requirement is that `dsh-tool-fs` dispatches these waterfalls on every write/edit path and that a config wiring the fs tools loads `dsh-fs-policy` as the policy decider.
|
||||
|
||||
The actor is typed `object` in `dsh-fs` — a pure opaque carrier the provider seam never reads or narrows. The owner-derivation (`actor.agent?.session`) and the `{ agent?: { session? } }` structural shape stay entirely inside `dsh-fs-policy`, which narrows the `object` actor to that shape in its listeners. `dsh-fs` owns the event names and the fs vocabulary; it does NOT own the policy layer's runtime owner structure.
|
||||
|
||||
```ts
|
||||
import type { FsTarget, FsVersion, FsWriteIntent } from '@deepseek-ai/dsh-fs'
|
||||
|
||||
interface Events {
|
||||
/**
|
||||
* Single-slot decision: produce the write expectation for the next
|
||||
* ctx.fs.writeText. The default returns undefined (unconditional create-or-
|
||||
* overwrite — the bare provider). The policy listener returns createIfAbsent
|
||||
* (unobserved) or { kind: 'replaceIfVersion', version: vObserved } (observed).
|
||||
* The listener does NOT call next(): one decision, not a composable chain. @mode waterfall
|
||||
*/
|
||||
'fs/write-intent'(target: FsTarget, actor: object | undefined, next: () => FsWriteIntent | undefined | Promise<FsWriteIntent | undefined>): Promise<FsWriteIntent | undefined>
|
||||
/**
|
||||
* Single-slot decision: produce the optional version guard for the next
|
||||
* ctx.fs.editText. The default returns undefined (unconditional edit of the
|
||||
* current content — the bare provider; no stat). The policy listener returns
|
||||
* { version: vObserved }, or throws FS_NOT_OBSERVED if the actor is unset or
|
||||
* has not observed the target. Does NOT call next(): one decision. @mode waterfall
|
||||
*/
|
||||
'fs/edit-intent'(target: FsTarget, actor: object | undefined, next: () => { version: FsVersion } | undefined | Promise<{ version: FsVersion } | undefined>): Promise<{ version: FsVersion } | undefined>
|
||||
/**
|
||||
* Record that an actor observed a target at a version, after a successful
|
||||
* read/write/edit. Fire-and-forget (plain emit). Listeners MUST be
|
||||
* synchronous, side-effect-only recorders (`dsh-fs-policy`'s is a WeakMap
|
||||
* write); the tool does not guard the emit, so a throwing listener surfaces as
|
||||
* the tool's isError result. No listener ⇒ nothing recorded.
|
||||
* @mode emit
|
||||
*/
|
||||
'fs/observed'(target: FsTarget, version: FsVersion, actor: object | undefined): void
|
||||
}
|
||||
```
|
||||
|
||||
The `fs/*` decision events are **unbound waterfalls dispatched by the tool** (like `agent/request`, which the loop dispatches with no `this`), not service-bound waterfalls (like `llm/stream`). The dispatcher is the `dsh-tool-fs` plugin, which is not a service.
|
||||
|
||||
## Tool contract (`dsh-tool-fs`)
|
||||
|
||||
The tool keeps its model-facing schemas (`read`/`write`/`edit`, byte-for-byte unchanged) and prompt sections. The prompt guidance stays policy-first because a deployment loading the fs tools is expected to also load `dsh-fs-policy`: the model is still told to read before overwriting or editing, and any wording that says the "backend" requires that should be corrected to say the fs-policy plugin requires it. The bare-provider fallback does not change the prompt stance.
|
||||
|
||||
`dsh-tool-fs` gains the executor responsibilities relocated from the old `fileContext` method service, including **read rendering** (`read-render.ts`: `buildWindow` + `formatReadOutput`, `READ_MAX_BYTES`, `READ_MAX_LINE_LENGTH`, `FileReadOutcome`/`FileTextLine`, plus `STREAM_MIN_SIZE` in `read.ts`), which is the tool's rendering detail now that the tool owns the read. Those read-rendering types and helpers move into `dsh-tool-fs`; the policy plugin must not remain a type dependency for the tool.
|
||||
|
||||
`dsh-tool-fs` is a single root plugin that registers all three tools (`read`/`write`/`edit`), mirroring `dsh-tool-bash`. It injects `fs` (plus `tools`/`systemPrompt`), never `fileContext`. (The original proposal also exposed each tool as a `/read`/`/write`/`/edit` subpath plugin for focused deployments; that was dropped on implementation — no consumer needed a single-tool deployment, and the subpath publishing forced bespoke `tsdown`/`tsconfig`/`files`/workspace-constraint handling no sibling tool package carries. The per-tool registration helpers (`applyReadTool`/`applyWriteTool`/`applyEditTool`) remain internal modules the root plugin composes.)
|
||||
|
||||
`stat` budget is minimized by letting the waterfall produce the expectation lazily — the bare default returns `undefined` (no guard) and never stats:
|
||||
|
||||
- **read** — one `stat` (type + size routing + version), then `readText`/`streamText`, then `buildWindow`, then an `emit('fs/observed', target, info.version, exec)`. The post-read confirming `stat` from the old `fileContext.read` is dropped; a writer racing between the routing stat and the read can at worst make a *later* guarded edit spuriously `FS_STALE_VERSION` (fail-closed: the model re-reads, never writes against the wrong version, since `editText` re-checks in its lock).
|
||||
- **write** — `expectation = await ctx.waterfall('fs/write-intent', target, exec, () => undefined)`, then `ctx.fs.writeText(target, content, expectation)`, then an `emit('fs/observed', target, outcome.version, exec)`. **Zero stat in the tool** with or without `dsh-fs-policy`.
|
||||
- **edit** — `expectation = await ctx.waterfall('fs/edit-intent', target, exec, () => undefined)`, then `ctx.fs.editText(target, edit, expectation)`, then an `emit('fs/observed', target, outcome.version, exec)`. **Zero stat in the tool** in both cases: the bare default is `undefined` (unconditional edit), so the tool never stats to manufacture a basis. If the target is absent, the provider reports `FS_STALE_VERSION` even on the unguarded path.
|
||||
|
||||
The tool passes `exec` (the tool-execution context) as the `actor` argument on every dispatch, so `dsh-fs-policy` can derive its observed-state owner. The tool does not know whether the policy plugin is present: it always provides the bare default behavior in the `next` thunk, and `dsh-fs-policy` short-circuits the thunk before it runs in the default deployment.
|
||||
|
||||
**`fs/observed` fires AFTER the mutation already succeeded**, via a plain `ctx.emit`. The event contract is intentionally narrow: an `fs/observed` listener MUST be synchronous and side-effect-only — `dsh-fs-policy`'s listener is a `WeakMap.set`, which cannot throw under normal operation and returns no promise. The tool does not guard the emit, so a listener that violates the contract by throwing would surface as the tool's `isError` result ([tools/index.ts](../../../../packages/core/tools/src/index.ts) — `ToolRegistry.execute` catches a tool throw into an error result) — reporting failure for a write/edit that actually happened. That is the price of keeping the event a plain fire-and-forget recorder: cordis `emit` does not await listener promises, so async or fallible audit/telemetry/listener work does not belong on this event. If layered or async observation is ever wanted, that is a new event with its own dispatch story.
|
||||
|
||||
## Policy plugin contract (`dsh-fs-policy`)
|
||||
|
||||
`dsh-fs-policy` is a plugin, not a service. It does not register `ctx.fileContext`, has no public method surface, and exposes no `read`/`write`/`edit`/`resolve` methods. It attaches three listeners via `ctx.on()` registrations (each returning a disposer for HMR). It keeps the observed-state `WeakMap<owner, Map<targetKey, { version }>>` and the structural owner derivation (narrowing the event's opaque `object` actor to its own `{ agent?: { session? } }` shape), but does not inject `fs` — every handler operates only on its own `WeakMap`, never on `ctx.fs`.
|
||||
|
||||
- `fs/write-intent` listener: `prior = getObserved(owner, key)`; return `prior ? { kind: 'replaceIfVersion', version: prior.version } : { kind: 'createIfAbsent' }`. It does NOT call `next()`: it fully owns the single decision slot.
|
||||
- `fs/edit-intent` listener: `prior = getObserved(owner, key)`; if no `owner` or no `prior`, throw `FS_NOT_OBSERVED`; else return `{ version: prior.version }`. Also does not call `next()`.
|
||||
- `fs/observed` listener: `record(owner, key, version)`.
|
||||
|
||||
An observed-state entry is the **prior-observation record**: a successful `read`, `write`, OR `edit` all emit `fs/observed` and record `{ version }`, so the entry's presence means "this owner has observed this target at this version", not narrowly "has read it". This is what lets a create-then-edit or edit-then-edit sequence work without an intervening re-read: the mutation refreshes the recorded version to its own result, so the next edit's basis is the version it just produced. `FS_NOT_OBSERVED` rejects only an edit with NO prior observation of any kind. The owner is derived structurally from `{ agent?: { session? } }`; disposal drops all state (HMR safety).
|
||||
|
||||
`dsh-fs-policy` is now a pure policy/recording plugin with no service surface — it influences the world only through the event seam. That is what removes the method coupling from `dsh-tool-fs`.
|
||||
|
||||
## Bare-provider behavior (no `dsh-fs-policy`)
|
||||
|
||||
This is not the intended deployment stance — a config loading the fs tools is expected to also load `dsh-fs-policy`. It is the unconstrained provider floor that exists once the tool is no longer coupled to a policy method service. With `dsh-fs-policy` absent, every `fs/*` waterfall falls through to its `undefined` default and `fs/observed` has no listener:
|
||||
|
||||
- **read** is identical (it never needed policy; it only emits a now-unheard `fs/observed`).
|
||||
- **write** unconditionally creates-or-overwrites: `expected` is `undefined`, so `writeText` writes whether or not the file exists and whatever its current version. No read-first requirement, no version check.
|
||||
- **edit** unconditionally replaces literal text in the file's current content: `expected` is `undefined`, so `editText` matches and rewrites without a version guard or a read-first requirement (`FS_EDIT_NOT_FOUND`/`FS_AMBIGUOUS_EDIT` still apply — those are about the literal match, not freshness). A missing target still reports `FS_STALE_VERSION`, matching the guarded edit path's "cannot edit this target now" code.
|
||||
|
||||
Both mutations are still atomic (the backend's per-target lock is unconditional). What is simply *absent*, not lost, is the policy `dsh-fs-policy` would add: observed-state, read-before-edit, and version-guarded write/edit. Loading `dsh-fs-policy` layers those constraints on by having its listeners return guarded `expected` values instead of `undefined`; nothing in the bare provider changes.
|
||||
|
||||
## Supersedes
|
||||
|
||||
This amends — does not reverse — [the split-fs-seam RFC](../simplification/2026-06-26-fsspec-style-fs-seam.md). The four-layer split, the provider contract, and the freshness *policy* are all kept. What changes is the **coupling between the tool and the policy layer**: a mandatory method service became a plugin-owned event gate, and the fs I/O + read windowing moved from `fileContext` up into `dsh-tool-fs`. The split-fs-seam RFC's description of `dsh-tool-fs` injecting `fileContext` and of `fileContext` owning `read`/`write`/`edit` was updated to match in the same change.
|
||||
|
||||
## Acceptance Criteria
|
||||
|
||||
- The `dsh-tool-fs` root plugin injects `fs` (+ `tools`/`systemPrompt`), not `fileContext`; it calls `ctx.fs` directly and dispatches the `fs/write-intent`/`fs/edit-intent` waterfalls (passing `exec` as the actor) and the `fs/observed` emit. Read rendering lives in `dsh-tool-fs`. (No subpath plugins — see the Tool contract above.)
|
||||
- `dsh-fs` declares the three events with `@mode` tags and an opaque `object` actor argument (no agent/session structure leaks into the provider vocabulary); the generated cordis catalog is regenerated.
|
||||
- `dsh-fs-policy` is a plugin, not a service: it does not register `ctx.fileContext`, has no public `read`/`write`/`edit`/`resolve` methods, and does not inject `fs`; it registers the three listeners, keeps observed-state, and has HMR/disposal coverage (dispose the fiber, assert the gate no longer rewrites).
|
||||
- **Bare-provider test**: a config WITHOUT `dsh-fs-policy` boots the `dsh-tool-fs` root plugin, and `read`/`write`(create AND overwrite)/`edit` work against the real `dsh-fs-local`; an `edit` of an unread existing file and an overwrite of an existing unread file both succeed (unconditional bare-provider behavior), proving the tool carries no `fileContext` dependency. A bare-provider edit of a missing target reports `FS_STALE_VERSION`. With `dsh-fs-policy` present, the same unread `edit` is rejected `FS_NOT_OBSERVED` and the same unread overwrite uses `createIfAbsent` (rejected on an existing file).
|
||||
- **Single-slot semantics**: a test registers a second `fs/edit-intent` listener AFTER `dsh-fs-policy` and asserts it is NOT reached (first-wins short-circuit), and documents in a comment that a decider registered before/`prepend`ed would instead win — the slot is first-wins by convention, not an enforced invariant.
|
||||
- **Fire-and-forget recording**: `fs/observed` is emitted via a plain `ctx.emit` after the mutation succeeds; a listener is contractually synchronous and side-effect-only, so the tool does not guard it.
|
||||
- `dsh-fs` `writeText`/`editText` make `expected` optional (omit ⇒ unconditional); the `FsWriteIntent` union is unchanged, and `dsh-fs-policy`'s guarded paths (`createIfAbsent`/`replaceIfVersion`/`{ version }`) behave exactly as today. A bare-provider test exercises an unconditional overwrite, an unconditional edit, and a missing-target edit reporting `FS_STALE_VERSION`.
|
||||
- Freshness is enforced by provider CAS when guarded: an edit after a stale read reports `FS_STALE_VERSION` (regression test); `dsh-fs-policy` performs no `stat`.
|
||||
- `stat` budget: read = 1, write = 0, edit = 0 — in the tool, with or without `dsh-fs-policy` (the bare default returns `undefined`, never stats). A test asserts neither write nor edit stats in the tool on either path.
|
||||
- Model-facing schemas stay byte-for-byte unchanged; snapshot transcript goldens are unaffected (or the diff is reviewed and re-recorded with justification).
|
||||
- Docs/artifacts updated in the same change: `docs/architecture.md`, fs package READMEs, `docs/core-data-structures/filesystem.md`, the split-fs-seam RFC's now-amended description, type-equiv blocks + manifest, cordis catalog, module graph. Gates green: `doc-sync`, `knip`, `test:coverage` (100% per-file).
|
||||
|
||||
## Risks
|
||||
|
||||
- **Event indirection over a method call.** A waterfall + emit is less direct than `await ctx.fileContext.edit(...)`. The payoff is removing the tool-to-policy method dependency while keeping the default policy plugin; the cost is one more event vocabulary to learn. Mitigated by keeping the three events narrow and documenting the default-thunk semantics on each.
|
||||
- **Policy events in the storage seam.** `dsh-fs` gains two version-decision events plus a recording event though it is "just storage". This is the price of decoupling (the emitter cannot depend on the policy plugin). The events carry only `dsh-fs` vocabulary plus an opaque `object` actor and no model-facing concepts, so the seam stays free of line-window/observation policy types and of the agent/session owner structure.
|
||||
- **Single policy occupant, first-wins by convention.** The `fs/write-intent`/`fs/edit-intent` slots hold exactly one decider; the first-registered (or `prepend`ed) listener wins and the rest are short-circuited. `dsh-fs-policy` owning the slot is a deployment convention, not an event-enforced invariant — a second decider registered first would bypass it. This is acceptable because a second fs-version-policy decider is a misconfiguration, not a feature. If a future need for *layered* fs version policy appears, it is a new RFC (a composable value-passing seam), not a silent second listener on these events. Layered permission/audit/sandbox interception already has its home on `tools/execute`.
|
||||
- **Dropping the post-read confirming stat** makes a follow-up *guarded* edit occasionally fail-closed (`FS_STALE_VERSION` → re-read) under a read/write race. This is a UX nicety lost, never a correctness hole; the provider lock still prevents wrong-version writes.
|
||||
- **The bare provider does no read-before-write/edit and no version check.** A deployment without `dsh-fs-policy` lets the model overwrite or edit any existing file unconditionally. This is the deliberate meaning of keeping the tool independent of a policy service: the safety disciplines live in the `dsh-fs-policy` plugin. A deployment that omits it is opting into an unconstrained filesystem on purpose; that is not the intended stance for a config that ships the fs tools.
|
||||
@@ -0,0 +1,33 @@
|
||||
# RFC: stdin + extra env on the bash seam
|
||||
|
||||
Status: implemented (accepted 2026-06-30)
|
||||
|
||||
<!-- XXX: legacy ADR/RFC body format, not yet normalized to a unified RFC template. -->
|
||||
|
||||
## Context
|
||||
|
||||
The hooks subsystem runs external hook commands the way Claude Code and Codex do: a hook is a shell command that receives its event payload as **JSON on stdin** and reads context from a handful of **environment variables** (`CLAUDE_PROJECT_DIR`, `CLAUDE_PLUGIN_ROOT`, `PLUGIN_ROOT`, …). The harness already has a perfectly good command runner behind the `ctx.bash` capability seam ([dsh-bash](../../../../packages/bash/bash) → [dsh-bash-local](../../../../packages/bash/bash-local)), with process-group kills, output truncation/spill, and a credential scrub. Reusing it for hook execution means a hook bridge does not re-implement subprocess plumbing — but the seam had no way to write stdin or set extra env. This RFC adds those two inputs.
|
||||
|
||||
**These fields are NOT a new security boundary.** It is tempting to frame arbitrary-stdin / arbitrary-env as "dangerous, so gate who may use them" — but that framing is wrong, because a model driving the `bash` tool **already** has equivalent power through ordinary shell syntax: `FOO=bar cmd` sets an env var, a heredoc or `printf … | cmd` feeds arbitrary stdin. Adding `env`/`stdin` as seam fields grants the model no capability it lacks. In particular they cannot exfiltrate the harness's ambient credentials: the real control for that is the **credential scrub** in [dsh-bash-local](../../../../packages/bash/bash-local)'s `childEnv()`, which strips `*KEY*`/`*SECRET*`/`*TOKEN*` from `process.env` before the child sees it (see [docs/defensive-patterns.md](../../../defensive-patterns.md) § "Never hand untrusted output the ambient environment or predictable paths"). The scrub works regardless of these fields — a model cannot read a value that is not in the environment, and tool-call arguments are static JSON, never shell-evaluated, so a model cannot write `env: {LEAK: $DEEPSEEK_API_KEY}` and have it expand. So the security question is already answered by the scrub; this RFC is only about giving trusted in-process callers a clean way to pass a JSON payload + `CLAUDE_*` vars without routing them through model-visible shell text.
|
||||
|
||||
## Decision
|
||||
|
||||
Add `stdin?: string` and `env?: Record<string, string>` to **both** `BashExecRequest` (the model-/plugin-facing request) and `BashExecSpec` (the resolved spec `run`/`start` act on), and thread them through `dsh-bash-local`: `resolve()` carries them verbatim, `run()`/`start()` pass them to `runBash`, which writes the bytes to the child's stdin and merges the extra env.
|
||||
|
||||
Three deliberate choices:
|
||||
|
||||
1. **The model-facing `bash` tool simply does NOT expose `stdin`/`env` as parameters** — not as a security wall, but because bash syntax already covers the model's needs, so duplicating them as tool params would be redundant surface. [dsh-tool-bash](../../../../packages/bash/tool-bash)'s `bash` tool builds its `BashExecRequest` from `command`/`workdir`/`timeoutMs`/`signal`/`owner` only; a model that includes `env`/`stdin` keys in its tool-call arguments simply has them ignored. A regression guard (`tool-bash` "does not forward env/stdin" tests) drives the real tool with those extra args and asserts the recorded request carries neither field — its purpose is to catch a future refactor that blindly spreads `...args` into the request and silently starts forwarding model input into the post-scrub `env` merge, NOT to defend a trust boundary. In-process plugins (the hooks bridges, native plugins) that construct a `BashExecRequest` directly set the fields; the seam imposes no access policy (consistent with how `owner` works — the executor stores but never interprets it).
|
||||
|
||||
2. **`env` merges AFTER the credential scrub, so an explicit caller entry always wins** — even a credential-shaped name. This is correct because the scrub's job is narrow: stop the harness's *ambient* `process.env` credentials from leaking into a spawned command. A caller that explicitly sets a var has named a value it already holds (not the ambient secret), so the scrub is not a constraint on it. `childEnv(extra?)` layers `scrub(process.env)` → `ENV_OVERRIDES` (the model-friendly `TERM=dumb` etc.) → `extra`, last-wins.
|
||||
|
||||
3. **`stdin`/`env` are required-absent-OK (plain optional) on the resolved spec, NOT required-but-nullable like `owner`.** `owner` is required-but-nullable because a *silently* missing owner yields an unowned, cross-session-readable task — a security footgun that a visible `undefined` guards against. `stdin`/`env` have no such hazard: a missing one means "no stdin / no extra env", which is the safe, ordinary case (every model-driven call). So they stay plain optionals, matching `signal`.
|
||||
|
||||
`dsh-bash-local` spawns stdin as a `'pipe'` (writing the supplied bytes, then closing) ONLY when a caller set `stdin`; with none supplied it uses `'ignore'` — fd 0 → `/dev/null` — the exact pre-seam default. This distinction is observable and deliberate: a closed empty pipe and `/dev/null` are NOT the same file type (node's spawn pipe is an `AF_UNIX` socket, so `test -c /dev/stdin` holds for `/dev/null` but not for an empty pipe), so the no-stdin path — every model-driven call — must keep `/dev/null` rather than regress to an always-open pipe. Each branch's `stdio` tuple is a literal, which preserves the typed `spawn` overload that guarantees non-null `stdout`/`stderr`. When stdin IS written, a child that exits without reading makes the write fail EPIPE; that error is swallowed (the command's outcome rides on its exit code/output, not the write) so it never crashes the host or rejects `done`.
|
||||
|
||||
## Scope: configurable scrub pattern is NOT included
|
||||
|
||||
An earlier sketch of this work also proposed making `SENSITIVE_ENV_PATTERN` configurable. Validating against the code, that is **speculative and already subsumed**: `run.ts` documents a configurable whitelist as future work, and the new explicit `env` field — merged after the scrub — already gives a caller full control, including over credential-shaped vars. There is no current caller that needs to *broaden* the ambient scrub (the hazard runs the other way). Adding a config knob now would be a speculative surface with no consumer. If a real workflow ever needs to forward a specific ambient credential, the explicit `env` field is the supported path; a configurable scrub can be reconsidered then.
|
||||
|
||||
## Consequences
|
||||
|
||||
A hook bridge builds a `BashExecRequest` with the hook's JSON payload as `stdin` and its `CLAUDE_*`/`PLUGIN_ROOT` vars as `env`, and runs it through the same `ctx.bash` everything else uses — no bespoke subprocess code, and the full process-group-kill / truncation / spill machinery for free. The model-facing attack surface is unchanged (the credential scrub, not these fields, is what bounds it), and the `bash` tool's request-building stays the single place that decides which fields a model call carries — guarded by a test that fails if a refactor starts forwarding model input. The vocabulary addition is documented in [docs/core-data-structures/bash.md](../../../core-data-structures/bash.md) (the `type-equiv` request/spec blocks) and the three bash-package READMEs.
|
||||
@@ -0,0 +1,35 @@
|
||||
# RFC: Event-domain semantics — session is the fact log, agent is the live surface
|
||||
|
||||
Status: implemented (accepted 2026-06-30)
|
||||
|
||||
## Context
|
||||
|
||||
The harness extends the agent loop through a Cordis event taxonomy (see [the microkernel event-taxonomy RFC](2026-06-11-microkernel-event-taxonomy.md)). As that taxonomy grew, the line between the three event domains blurred:
|
||||
|
||||
- `session/*` carries the durable, event-sourced log (`SessionEventMap`).
|
||||
- `agent/*` carries live runtime signals that hand a plugin the `Agent` handle.
|
||||
- `tools/*` carries the tool registry + execution seam.
|
||||
|
||||
Two problems motivated pinning the semantics down. First, several turn/step boundaries existed BOTH as a durable `SessionEvent` (`turn/start`, `turn/end`, `step/start`, `step/end`) AND as a mirrored `agent/*` emit (`agent/turn-start`, `agent/turn-end`, `agent/step-start`, `agent/step-end`). A consumer had two sources of truth for the same fact, and every lifecycle change had to update both. Second, the upcoming Hooks subsystem needs ONE coherent, documented surface to subscribe to — a plugin author (and the Claude Code / Codex hook bridges built on top) must know, without reading the loop, whether to listen on a session event or an agent event, and why.
|
||||
|
||||
This is the foundational change in a stack that adds a Hooks subsystem; it establishes the vocabulary the later PRs (interception-Decision reshape, the `hook/*` durable log, the bridges) build on.
|
||||
|
||||
## Decision
|
||||
|
||||
**Three domains, one job each, with a single boundary rule.**
|
||||
|
||||
- **`session/*` — the durable, replayable FACT log.** Owns `SessionEventMap`; every entry is JSON-only (no live objects). One `session/event` emit per append, plus the `session/flush` parallel durability checkpoint. It is also the live transcript feed: a consumer that wants to render or react to what happened subscribes here, so live rendering and `session/load` replay share one path.
|
||||
- **`agent/*` — the LIVE runtime surface.** Always carries the live `Agent`. Two shapes: INTERCEPTION waterfalls (`agent/request`, `agent/step-result`, `agent/turn-continuation`) that mutate or veto, and TRANSIENT emits (`agent/status`, `agent/error`, `agent/created`/`agent/disposed`, `agent/queued`, `agent/steering`) that notify with the `Agent` in hand. Turn and step BOUNDARIES are NOT here — they are durable session events read off `session/event`, and so is the token stream (`assistant/chunk`).
|
||||
- **`tools/*` — the tool registry + execution seam.**
|
||||
|
||||
**The boundary rule:** a durable, replayable fact is a `SessionEvent`; a live interception or a transient/live-object signal is an `agent`/`tools` Cordis event. A turn or step boundary is a durable fact, so it lives in the session log and is read off the `session/event` feed — it is NOT mirrored as an `agent/*` emit.
|
||||
|
||||
**Applying the rule to the boundary twins:** all four boundary mirrors — `agent/turn-start`, `agent/turn-end`, `agent/step-start`, `agent/step-end` — are **REMOVED**. No production consumer needs the live `Agent` at a boundary: the ACP bridge settles from `session/event` `turn/end` plus `agent/status`, and the only turn-mirror consumer (`dsh-ui-stdio`, a disposable test REPL) was migrated to render boundaries from `session/event`, recovering the short agent label from an `agent/created`→id map. The step mirrors were removed first (they had no consumer at all); the turn mirrors followed once ui-stdio was migrated — see [the remove-boundary-mirror-events RFC](../simplification/2026-06-20-remove-agent-boundary-mirror-events.md), which owns that decision. Removing the emits also simplifies the loop's `closeStep`/`closeTurn` (one append each, no paired emit).
|
||||
|
||||
## Consequences
|
||||
|
||||
- The loop no longer emits any boundary mirror; `closeStep` appends `step/end` only and `closeTurn` appends `turn/end` only. A throwing `step/end`/`turn/end` session-event listener is the surviving boundary-listener failure path (contained inside `closeStep`/`closeTurn` — `Session.append` pushes the event before notifying listeners, so the boundary is durable and the turn closes balanced regardless).
|
||||
- Tests that observed boundaries via the removed emits now observe the durable `turn/start`/`turn/end`/`step/start`/`step/end` session events — the behavior they pin (boundary ordering, step counting) is unchanged; only the feed they read moved to the canonical one. The tests that exercised a *throwing turn-boundary emit listener* were deleted, because that code path no longer exists (there is no emit to throw from). Per [AGENTS.md "tests document behavior, not golden truth"](../../../../AGENTS.md), the behavior and its test moved (or died) together.
|
||||
- The loop marks the step open (`stepOpen = true`) BEFORE appending `step/start`, because `Session.append` pushes the event to the log before notifying `session/event` listeners (validation throws happen earlier, before the push — see [the session append contract](../../../core-data-structures/session.md)). So a throwing `step/start` session-event listener runs with the step already open and the event already in the log: the loop's outer catch then calls `closeStep()`, which appends the balancing `step/end`, and the turn closes balanced with an error (`turn/start → step/start → step/end → turn/end` — verified by the invariants oracle in the regression test). Closing the open step is owed precisely because the marker is set first.
|
||||
- The full realization of this is [the simplification RFC "Stop mirroring durable boundaries as agent events"](../simplification/2026-06-20-remove-agent-boundary-mirror-events.md): all four boundary mirrors are removed and every consumer reads boundaries off `session/event`. `agent/steering` (a live control signal, not a boundary mirror) is retained; see that RFC's scope section.
|
||||
- The cordis catalog (`docs/cordis-catalog/events-and-services.md`) is regenerated to drop the mirror events.
|
||||
@@ -0,0 +1,30 @@
|
||||
# RFC: Resolve filesystem paths against the caller's session cwd
|
||||
|
||||
Status: implemented
|
||||
|
||||
## Problem
|
||||
|
||||
The ACP bridge gives every session its own workspace: `session/new` records the editor's project directory as `SessionHeader.cwd`, and `dsh-tool-bash` defaults each bash call's `workdir` to the calling agent's `session.header.cwd` (see [the per-session cwd RFC work in `packages/ui/acp`](../../../../packages/ui/acp) and `resolveWorkdir` in `dsh-tool-bash`). So a bash command in session A runs in A's project, and in session B runs in B's — one server process, N workspaces.
|
||||
|
||||
The filesystem tools did NOT honor this. `ctx.fs.resolve(path)` took no caller context, and `dsh-fs-local` resolved every relative path against a single `config.cwd` fixed at plugin load (`process.cwd()`). In the ACP demo that means `write foo.txt` and `bash cat foo.txt` resolve `foo.txt` against **different** directories — the fs tools against the server's launch dir, bash against the session's project dir. The two tools disagree about what "the current directory" is, which is a correctness bug the moment an editor opens any project other than the server's launch dir. It only appeared to work in the snapshot harness because that harness launches the child process in the same temp dir it passes as the session cwd, so the two coincide.
|
||||
|
||||
## Decision
|
||||
|
||||
Thread the caller's session cwd into path resolution, exactly as `dsh-tool-bash` already does for `workdir`. The **caller** (the tool) supplies the cwd; the provider does not read a session or agent.
|
||||
|
||||
- `FileSystem.resolve` widens to `resolve(path: string, opts?: { cwd?: string }): Promise<FsTarget>`. `opts.cwd` is the base a RELATIVE `path` resolves against; an absolute `path` ignores it; omitting `opts.cwd` uses the backend's own default. An options object (not a positional `cwd?`) leaves room for future resolution hints without another signature change.
|
||||
- `dsh-fs-local.resolve` uses `resolveLocalTarget(opts?.cwd ?? this.config.cwd, path)`. `config.cwd` stays the default for a caller that supplies none (non-ACP / no-session use, and the single-session stdio demo where `process.cwd()` IS the workspace).
|
||||
- `dsh-tool-fs`'s `read`/`write`/`edit` derive the session cwd through a shared `sessionCwd(exec)` helper (`exec.agent?.session.header.cwd`, mirroring bash's `resolveWorkdir`) and pass it to `resolve`. A non-agent / headerless caller yields `undefined`, so the backend applies its default.
|
||||
|
||||
## Why the caller supplies the cwd (not the provider)
|
||||
|
||||
The provider seam must not depend on `dsh-agent` / `dsh-session` — it is a text-storage backend that a sandboxed or remote implementation also satisfies, and those have no notion of an "agent session". The tool already receives the `ToolExecution` (`exec`), which carries the agent, so the tool is the right place to project `exec → cwd` and hand the provider a plain string. This is the "explicit > implicit at package seams" convention: the base directory arrives as an explicit argument the provider acts on, not smuggled in by having the provider reach into a session it should not know about. It also matches `dsh-tool-bash` one-to-one, so the two model-facing file surfaces resolve paths identically.
|
||||
|
||||
The default lives in ONE place — the provider's `config.cwd`. `sessionCwd` returns `undefined` rather than `process.cwd()` when there is no session, so the tool never manufactures a base the provider would otherwise choose.
|
||||
|
||||
## Consequences
|
||||
|
||||
- In the ACP demo the fs tools and bash now agree on each session's workspace; an editor can open any project folder and both tool families act on it.
|
||||
- No change to `FsTarget` identity: `targetKey` is still the realpath of the resolved absolute path, so observed-state keying and symlink identity are unaffected — a correct per-session cwd produces the same key bash targets.
|
||||
- Backward compatible: every existing `resolve(path)` call (all in tests) keeps working; the new argument is optional.
|
||||
- The single-session stdio demo is unaffected: it supplies no session cwd (its agent's session has no `cwd`), so resolution falls back to `config.cwd = process.cwd()`, which is the workspace.
|
||||
@@ -0,0 +1,55 @@
|
||||
# RFC: Result-time applied-hunk diffs for file mutations
|
||||
|
||||
Status: implemented
|
||||
|
||||
## Problem
|
||||
|
||||
The [tagged render-intent union](2026-07-02-tool-render-intent-union.md) gave `dsh-tool-fs` write/edit a `card:'diff'` at CALL time, derived purely from the tool's args: write ⇒ `{oldText:null, newText:content}` (the whole new file), edit ⇒ `{oldText:old_string, newText:new_string}` (the bare replaced snippet). An editor renders that as an inline diff, but it is a **context-free** diff — the bare `old_string`→`new_string` with no surrounding lines, and a `replace_all` that touched five scattered sites still renders as one snippet pair.
|
||||
|
||||
Driving `claude-agent-acp`'s own ACP bridge shows what a full editor diff looks like: after the mutation applies, it emits a SECOND `tool_call_update` whose diff is the **applied hunk with ±3 context lines** (and one hunk per changed site for `replace_all`), reconstructed from the tool's `structuredPatch`. That result-time hunk is what makes Zed show the change *in place* in the file rather than as a floating snippet. Our tools stopped at the call-time snippet; the completed result carried only the plain "updated successfully" text, no diff.
|
||||
|
||||
The obstacle is a seam boundary: `presentResult(args, result)` is a **pure function of `args` + the model-facing `result` (`{content, isError}`)** — it runs on live streaming AND on session-log replay, so it must be replay-deterministic and cannot do I/O. It never sees the file's before/after content, and `FsEditOutcome`/`FsWriteOutcome` carried only a replacement count + version, not the text. So there was no way to compute — or even carry — an applied hunk to the presenter.
|
||||
|
||||
## Decision
|
||||
|
||||
Add a **persisted, tool-private presentation channel** so a tool's `execute` can attach a result-time render payload that survives replay, and use it to carry the applied-hunk diff.
|
||||
|
||||
### 1. A `meta` channel on the tool result (core)
|
||||
|
||||
`ToolDefinition.execute` may now return either its model-facing `ContentBlock[]` (unchanged, the common case) OR `{ content: ContentBlock[]; meta?: unknown }`:
|
||||
|
||||
```ts ignore-check
|
||||
type ToolExecuteReturn = ContentBlock[] | { content: ContentBlock[]; meta?: unknown }
|
||||
```
|
||||
|
||||
`meta` is an opaque payload the core never interprets — typed `unknown` at every seam (the tool that produced it owns and narrows its shape). It MUST be JSON-serializable: the registry threads it onto the `tool/result` **session event**, and `Session.append` runtime-validates all event data with the existing `isJsonValue` predicate, so a non-serializable `meta` is rejected at the source. On replay the same `meta` is read back and handed to `presentResult` via a widened `ToolResult` (`{ content, isError, meta? }`). Because the payload lives in the event log, the diff reproduces on session reload / snapshot replay **for free** — the event-sourcing guarantee, not a re-computation. Typing `meta` as `unknown` (rather than a shared serializable-value type) keeps the tools core free of a dependency it would otherwise take just to name the type, and the runtime `isJsonValue` gate — not the static type — is what actually enforces serializability.
|
||||
|
||||
This is the general shape ("a tool attaches durable result presentation"), not an fs-specific one — any tool can use it.
|
||||
|
||||
### 2. The tool computes the hunk; the backend returns before/after (fs)
|
||||
|
||||
Per the [capability-seam split](2026-06-13-capability-seams.md), the storage backend returns only **storage facts** and the model-facing tool owns **presentation**:
|
||||
|
||||
- `dsh-fs` widens `FsEditOutcome` with `{ before: string; after: string }` and `FsWriteOutcome` with `{ before: string | null; after: string }` (`before: null` ⇒ a create, or an existing-but-undiffable binary/non-UTF-8 file). The local backend already holds both texts at write time; it returns them as raw LF-normalized text, with **no diff/UI concept** entering the seam.
|
||||
- `dsh-tool-fs` computes the contextual hunk from before/after and attaches it as `meta: { diffs: FileDiff[] }`. A contextual hunk is computed only when a before-version exists — edit always; write on overwrite; a create has no before, matching `claude-agent-acp`'s empty `structuredPatch` on create. But the completed `tool_call_update` is ALWAYS a `diff` card for a successful mutation: an ACP `tool_call_update.content` REPLACES the call's content, so rendering the model-facing result text would clobber the pending diff. So `write`'s result falls back to an args-derived whole-file diff (`oldText: null`) when it has no contextual hunk (a create, or an overwrite whose content is unchanged), and `edit` — which always changes content — always has a hunk. A failed/aborted/policy-rejected mutation applied nothing, so it carries no `meta` and falls through to the generic error rendering (its message must show).
|
||||
|
||||
### 3. The bridge renders a `diff` result card
|
||||
|
||||
`ToolResultView` gains a `DiffResultView { card:'diff'; title?; diffs: FileDiff[] }`; the bridge's result-side `switch (view.card)` gets a `diff` arm emitting the `{type:'diff'}` `ToolCallContent` blocks (mirroring the call-side arm). An ACP `tool_call_update.content` REPLACES the call's content in an editor, so the result diff **supersedes** the call-time snippet (and keeps the model-facing result text from clobbering it) — the two-update sequence (call snippet, then result diff) matches `claude-agent-acp` exactly.
|
||||
|
||||
### The diff algorithm — a third-party runtime dependency over vendoring
|
||||
|
||||
Computing hunks-with-context is a solved problem with sharp edge cases (grouping, context coalescing, the trailing-newline marker). Rather than hand-roll it, `dsh-tool-fs` takes a runtime dependency on the npm [`diff`](https://www.npmjs.com/package/diff) package (a `^9.0.0` range, exact-pinned by the lockfile; it ships its own types) and uses its `structuredPatch`. The repo's default is to vendor Cordis-framework source, but that policy is about the *framework*; a leaf tool package taking a small, well-known, self-typed utility dependency is the same shape as `dsh-acp` depending on `@agentclientprotocol/sdk`. Vendoring a diff algorithm would be re-implementing a battle-tested one for no benefit — the [pre-release "foundation over blast radius"](../../../../AGENTS.md) reasoning does not argue for re-deriving standard algorithms. The dependency's output is normalized in one small module (`packages/fs/tool-fs/src/diff.ts`).
|
||||
|
||||
## Non-goals
|
||||
|
||||
- **Live incremental diff streaming.** The hunk is computed once, after the mutation completes; there is no per-keystroke diff.
|
||||
- **Diffing a binary/non-UTF-8 overwrite.** `before` is `null` for such a file (it has no text diff basis); the write still succeeds and the result renders a whole-file diff (`oldText: null`) rather than a contextual hunk.
|
||||
- **Rename/move diffs.** Only content diffs of a single resolved path.
|
||||
- **Bounding the overwrite diff basis.** An overwrite reads the whole prior file into memory to compute the contextual hunk (on top of the new content already held), so a very large text overwrite allocates both texts for a UI-only diff. A future refinement can bound the pre-read and fall back to a whole-file / no contextual diff above a size threshold; tracked as `TODO(overwrite-diff-bound)` at the read site.
|
||||
|
||||
## Related
|
||||
|
||||
- Completes the one remaining representation difference named as a non-goal in [Tagged render-intent union](2026-07-02-tool-render-intent-union.md) — that RFC's Non-goals section is updated to record that applied-hunk diffs shipped here.
|
||||
- Builds on the [filesystem capability seam](2026-06-17-filesystem-capability-seam.md) (the before/after are storage facts the backend returns) and [event-sourced sessions](2026-06-11-event-sourced-sessions.md) (the `meta` payload persists on the `tool/result` event, so replay reproduces the card).
|
||||
- The `meta` channel is deliberately generic: a future tool (a structured search, a data-table result) can attach its own durable result presentation without another core change.
|
||||
@@ -0,0 +1,70 @@
|
||||
# RFC: Tagged render-intent union for tool-call presentation
|
||||
|
||||
Status: implemented
|
||||
|
||||
## Problem
|
||||
|
||||
A tool declares how its calls render in a UI (an editor's tool-call card) through two callbacks, `presentCall`/`presentResult` on `ToolDefinition`, returning `ToolCallPresentation` / `ToolResultPresentation` with an optional `ToolTerminal` sub-shape. These grew incrementally into a **bag of optional fields**: `title`, `kind`, `rawInput`, `content`, `locations`, `terminal` on the call; `title`, `content`, `terminal` on the result; `cwd`/`output`/`exitCode`/`signal` on `ToolTerminal`. The split of responsibility is muddy:
|
||||
|
||||
- The call-side and result-side `terminal` fields overlap, and the bridge reconciles a `content` block AND a `terminal` block AND `rawInput` per call, stitching them together with ad-hoc conditionals.
|
||||
- Which combinations are *valid* is unwritten: a `terminal` call that also sets `content` means "description above the card"; a generic call that sets `terminal` is meaningless but representable. The type permits nonsense.
|
||||
- There is no way to express the one file-tool affordance an editor most wants — a **diff card** (`{path, oldText, newText}`, which Zed renders as an inline diff / new-file preview). `ToolCallPresentation.content` is the *LLM* `ContentBlock[]` vocabulary (text/image), so a tool literally cannot ask for a diff.
|
||||
|
||||
The existing `FIXME(tool-presentation)` in `packages/core/tools/src/index.ts` named the fix: "redesign the type so a tool declares its render INTENT once (e.g. a tagged union over card kinds) rather than a bag of optional fields the bridge stitches together." The rejected RFC [Collapse tool-owned UI presentation](../../rejected/simplification/2026-06-20-generic-tool-rendering.md) deferred it explicitly: rich rendering "should return later as a tagged render-intent union after there are at least two real tools and two real consumers to validate the vocabulary." That bar is now met — two producer families (`dsh-tool-bash`, `dsh-tool-fs`) and two consumers (the ACP bridge live path + the snapshot-golden replay path).
|
||||
|
||||
## Decision
|
||||
|
||||
Replace the optional-field bag with a **`card`-tagged discriminated union**. A tool declares one render intent per call/result; the bridge switches on the tag.
|
||||
|
||||
```ts ignore-check
|
||||
type FileLocation = { path: string; line?: number }
|
||||
type FileDiff = { path: string; oldText: string | null; newText: string } // oldText null ⇒ new file
|
||||
|
||||
// presentCall → ToolCallView
|
||||
type ToolCallView = GenericCallView | TerminalCallView | DiffCallView
|
||||
interface GenericCallView { card: 'generic'; title: string; kind?: ToolCallKind; rawInput?: unknown; content?: ContentBlock[]; locations?: FileLocation[] }
|
||||
interface TerminalCallView { card: 'terminal'; title: string; description?: string; cwd?: string }
|
||||
interface DiffCallView { card: 'diff'; title: string; diffs: FileDiff[]; locations?: FileLocation[] }
|
||||
|
||||
// presentResult → ToolResultView
|
||||
type ToolResultView = GenericResultView | TerminalResultView
|
||||
interface GenericResultView { card: 'generic'; title?: string; content?: ContentBlock[] }
|
||||
interface TerminalResultView { card: 'terminal'; title?: string; output?: string; exitCode?: number; signal?: string }
|
||||
```
|
||||
|
||||
`card` is **required** on every variant — a real discriminant, not an optional default. The bridge does `switch (view.card) { case 'generic': … case 'terminal': … case 'diff': … default: assertNever(view) }`. The union is **closed** (per the [switch-exhaustiveness convention](../../../../AGENTS.md)): a fourth render intent (a table, a chart) needs new bridge code to render it anyway, so a plugin-added variant that the bridge silently drops would be worse than a compile error. Adding a variant breaks compilation at the bridge switch — exactly the signal we want.
|
||||
|
||||
### Why a tagged union beats the field-bag
|
||||
|
||||
- **Invalid states become unrepresentable.** A generic card cannot carry terminal output; a terminal card cannot carry a diff. The old bag permitted all of these.
|
||||
- **The bridge switches instead of stitching.** One arm per card kind, each producing exactly the wire shape that card needs, rather than reconciling five optional fields whose interactions are undocumented.
|
||||
- **`diff` is a first-class intent.** `dsh-tool-fs` write/edit declare `card:'diff'`; the bridge emits an ACP `{type:'diff', path, oldText, newText}` `ToolCallContent` (already in the SDK's `ToolCallContent` union, previously unused by the bridge). This is the affordance the redesign unlocks.
|
||||
|
||||
### Producer mapping
|
||||
|
||||
- `dsh-tool-fs` read → `generic` (`kind:'read'`, a follow-along `location`); write → `diff` (`oldText:null`); edit → `diff` (`oldText:old_string || null`, `newText:new_string ?? ''`). This mirrors `claude-agent-acp`'s `toolInfoFromToolUse` Read/Write/Edit arms field-for-field.
|
||||
- `dsh-tool-bash` foreground → `terminal` call + `terminal` result; `run_in_background` and `bash_output`/`bash_kill` → `generic`.
|
||||
- `dsh-tool-todo` → `generic`.
|
||||
|
||||
### Terminal fallback ownership
|
||||
|
||||
`TerminalResultView` carries only `output`/`exitCode`/`signal`. A UI without the terminal capability needs a fenced ` ```console ` text fallback; that derivation moves to the **bridge** (it wraps `output` in a fenced block on the no-capability path), rather than the tool double-encoding it. This keeps the bash tool's result a single structured shape and preserves the existing capability-gated behavior byte-for-byte.
|
||||
|
||||
### Purity preserved
|
||||
|
||||
`presentCall`/`presentResult` remain pure functions of `args` (+ the result for `presentResult`) — they run on live streaming AND session-log replay, so they must be replay-deterministic. Every view is derived from args alone: write's diff is new-file style (`oldText:null`) because the tool has no old content at call time; edit's diff is `old_string`→`new_string`.
|
||||
|
||||
## Relative-path display titles
|
||||
|
||||
`claude-agent-acp` relativizes a file card's title path against the session cwd (`toDisplayPath`) — `Read src/foo.ts`, not `/abs/proj/src/foo.ts` — while keeping `locations[]`/`diff.path` **raw** (the editor opens the real path). Our `presentCall` is pure/args-only and cannot see the session cwd, so this relativization happens at the **bridge**, which already threads the session cwd into tool-call rendering (the same cwd it uses to resolve a terminal card's header). The bridge relativizes the title only, by an exact structured replace of the known `locations[0].path`/`diffs[0].path` substring — generic over the file-card kinds, never special-casing tool names.
|
||||
|
||||
## Non-goals
|
||||
|
||||
- **Live incremental `terminal_output_delta` streaming** and **command classification** — the terminal-rendering RFC's own deferred follow-ups, untouched here.
|
||||
|
||||
## Related
|
||||
|
||||
- Supersedes the deferral in [Collapse tool-owned UI presentation](../../rejected/simplification/2026-06-20-generic-tool-rendering.md) (rejected — "wait for two real tools and two real consumers, then a tagged render-intent union"). That bar is now met; this is that union.
|
||||
- Extended by [Result-time applied-hunk diffs](2026-07-02-result-time-applied-hunk-diffs.md), which adds a persisted `meta` channel so write/edit emit a result-time `DiffResultView` — the applied change (a contextual hunk with context lines / one per `replace_all` site, or a whole-file diff for a create) — on top of this union's call-time diff card.
|
||||
- Folds `ToolTerminal` into the `terminal` views described by [ACP terminal and tool-call rendering](../feature/2026-06-18-acp-terminal-and-tool-rendering.md) (the `_meta` terminal-card convention and capability gate are unchanged; only the harness-side presentation type changes).
|
||||
- The ACP SDK's `Diff` / `ToolCallContent` types back the new `diff` card.
|
||||
@@ -0,0 +1,53 @@
|
||||
# Add direct directory listing to the filesystem seam
|
||||
|
||||
## Status
|
||||
|
||||
Implemented.
|
||||
|
||||
## Context
|
||||
|
||||
`@deepseek-ai/dsh-fs` is the provider seam for filesystem access, with local and future non-local backends behind the same `ctx.fs` contract. Before this change it could resolve paths, stat targets, read text, stream text, write text, and edit text. That was enough for model-facing file tools, but not for non-model-facing consumers that need to enumerate directories without importing `node:fs`.
|
||||
|
||||
The immediate pressure came from skill loading: reading an individual `SKILL.md` can already go through `ctx.get('fs')`, but discovering which skill roots contain `<name>/SKILL.md` or `<name>.md` still needs directory enumeration. Adding directory listing only in `dsh-skill` would either keep a direct Node dependency there or invent a one-off local helper outside the filesystem provider stack.
|
||||
|
||||
This branch deliberately lands the provider capability first and does not add a model-facing `ls`/`list` tool or change skill discovery. The follow-up consumer can validate UX and prompt shape separately, while this PR establishes the backend seam and local implementation.
|
||||
|
||||
## Decision
|
||||
|
||||
Add `FileSystem.listDir(target, signal?)` to `@deepseek-ai/dsh-fs`.
|
||||
|
||||
`listDir` lists one directory level only. It returns direct children in stable name order and includes:
|
||||
|
||||
- `name`: the child basename.
|
||||
- `type`: `file`, `directory`, or `other`.
|
||||
- `target`: the resolved child `FsTarget`.
|
||||
- `version`: cheap metadata when available.
|
||||
- `size`: regular-file size when available.
|
||||
|
||||
It never reads file contents. Recursive traversal, globbing, pagination, search, file watching, and model-facing rendering are intentionally out of scope.
|
||||
|
||||
The local backend implements this through `readdir({ withFileTypes: true })`, `resolveLocalTarget`, and metadata `stat`/`realpath` probes. The result order is deterministic (`name.localeCompare`) to keep prompt/listing output stable for future consumers and improve prefix-cache reuse.
|
||||
|
||||
Broken or disappeared children may be represented as `type: 'other'` without `version`/`size`; they do not abort the whole listing. Permission or backend I/O failures while listing the directory or resolving/probing child metadata fail the whole listing with structured `FsError` codes:
|
||||
|
||||
- `FS_NOT_FOUND` for missing targets.
|
||||
- `FS_NOT_DIRECTORY` for existing non-directory targets.
|
||||
- `FS_PERMISSION_DENIED` for permission failures.
|
||||
- `FS_IO_ERROR` for other backend I/O failures.
|
||||
- `FS_ABORTED` for aborted calls.
|
||||
|
||||
## Rejected alternatives
|
||||
|
||||
**Add a model-facing list tool now.** Rejected for this PR. The immediate request is the provider seam, and the user explicitly asked not to change skill loading or other upper layers in this branch. A model-facing tool needs prompt/schema/rendering decisions that should be reviewed separately.
|
||||
|
||||
**Keep directory enumeration in each consumer.** Rejected. That would bind product packages such as `dsh-skill` to Node/local filesystem behavior and bypass policy/remote/sandboxed backends.
|
||||
|
||||
**Make `listDir` recursive or glob-shaped.** Rejected for now. Skill-root discovery only needs direct children, and a simple direct listing is the smallest backend contract future consumers can safely compose.
|
||||
|
||||
**Skip children that fail metadata resolution.** Rejected. The API promises resolved child targets, so permission/IO failures while resolving a child are contract failures. Broken or disappeared children are the exception because they can still be represented without claiming a live resolved file.
|
||||
|
||||
## Consequences
|
||||
|
||||
Every filesystem backend must now implement one additional provider primitive. That is deliberate foundation work while the harness is still unreleased, but it does mean future sandboxed/remote backends need to define equivalent direct-child listing behavior.
|
||||
|
||||
The capability remains provider-facing. Until a consumer lands, ACP/model sessions will still need existing tools such as `bash` for directory listing. The absence of a model-facing `listdir` tool is expected, not a wiring failure.
|
||||
Reference in New Issue
Block a user