Merge origin/master into parallel-tool-call

docs/rfc/implemented/feature/2026-06-21-subagent-capability-seam.md

@@ -67,6 +67,6 @@ The seam is tested through the real Cordis Loader/export path, which catches the
 ## Consequences
 
 - **Recursion.** Without a bound, an in-process child can see the delegation tool and recurse. The in-process backends implement the optional absolute depth limit and scoped live-global `toolFilter`; ACP advertises both capabilities off and rejects such a request. The [subagent composition-controls RFC](2026-07-12-subagent-persona-tool-filter-and-depth.md) owns their exact semantics and security limits.
-- **Blocking the parent turn.** Synchronous collect holds the parent's `runStep` open for the child's full duration. This is acceptable for the first cut; **background / poll / spill semantics are deferred to a future redesign that unifies long-running-tool handling across subagents AND bash** (a sub-agent and a long `bash` background task pose the same "the model started something slow, how does it collect later" problem, and should share one mechanism rather than each inventing its own).
+- **Blocking the parent turn.** Foreground collection holds the parent's step open for the child's full duration. Background delegation uses the shared `ctx.tasks` runtime and generic `task_*` tools, the same collection mechanism as background bash; the subagent seam itself remains task-agnostic.
 - **Live progress.** This cut surfaces only lifecycle + final result; a per-chunk child→parent update stream is deferred with the background redesign.
 - **ACP client surface.** Proxying `fs`/`terminal` from the ACP child back to the parent (a shared-workspace mode) is future work; the first cut advertises neither, so the child self-serves in its own process.

docs/rfc/implemented/feature/2026-06-25-ask-user-question.md

@@ -20,7 +20,7 @@ Providers return `{ answers: [{ id, selected, custom? }] }`. `selected` is alway
 
 ## UI mappings
 
-`dsh-stdio-agent`'s in-package readline module renders each question, shows each option's `description` on the next line, supports comma/space-separated numeric choices for `multi_select`, accepts free-form custom answers, and rejects pending questions on abort, provider disposal, or stdin EOF. A batched request is asked in order and resolved as one answer object. The stdio provider serializes simultaneous requests with an internal queue so only one prompt owns stdin at a time.
+`dsh-stdio-demo`'s in-package readline module renders each question, shows each option's `description` on the next line, supports comma/space-separated numeric choices for `multi_select`, accepts free-form custom answers, and rejects pending questions on abort, provider disposal, or stdin EOF. A batched request is asked in order and resolved as one answer object. The stdio provider serializes simultaneous requests with an internal queue so only one prompt owns stdin at a time.
 
 `dsh-acp` provides the same seam for ACP sessions. It routes an ask request from the calling `Agent` through the bridge's `agent→sessionId` reverse map and calls ACP `unstable_createElicitation` with a session-scoped form for each question. Single-select options become a `choice` string enum; `multi_select` options become a `choice` array enum; optionless questions use a required `custom` text field. If the client returns both `choice` and non-empty `custom`, the custom answer wins. ACP `decline`/`cancel`, a missing answer, a missing session, and a client without elicitation support all become structured `UserInteractionError`s.
 
@@ -46,4 +46,4 @@ The feature gives the model a powerful pause primitive, so prompt guidance matte
 
 ## Testing
 
-Unit coverage pins provider registration/disposal, duplicate-provider rejection, abort-before-provider, empty-question rejection, structured tool errors through `ctx.tools.execute()`, batched answers, multi-select answers, custom answers, and the model schema including the removal of `value`, `recommended`, `allow_custom`, and `desc`. `dsh-stdio-agent` tests cover option descriptions, queued requests, EOF/abort cleanup, optionless free-form input, invalid option reprompts, duplicate multi-select numbers, and batched question flows. ACP bridge tests drive a real in-memory ACP connection with the real `ask_user_question` tool and verify selected-option, custom-overrides-choice, multi-select, and optionless free-form elicitation paths continue the agent loop.
+Unit coverage pins provider registration/disposal, duplicate-provider rejection, abort-before-provider, empty-question rejection, structured tool errors through `ctx.tools.execute()`, batched answers, multi-select answers, custom answers, and the model schema including the removal of `value`, `recommended`, `allow_custom`, and `desc`. `dsh-stdio-demo` tests cover option descriptions, queued requests, EOF/abort cleanup, optionless free-form input, invalid option reprompts, duplicate multi-select numbers, and batched question flows. ACP bridge tests drive a real in-memory ACP connection with the real `ask_user_question` tool and verify selected-option, custom-overrides-choice, multi-select, and optionless free-form elicitation paths continue the agent loop.

docs/rfc/implemented/feature/2026-07-05-skill-system.md

@@ -10,9 +10,9 @@ DeepSeek Harness uses the same primitive so project-specific review, plugin-auth
 
 ## Decision
 
-`@deepseek-ai/dsh-skill` is the pure provider registry (`ctx.skills`), `@deepseek-ai/dsh-skill-local` is the shipped local filesystem provider, and `@deepseek-ai/dsh-tool-skill` owns the session-prefix catalog and model-facing loader tool. `dsh-agent-core` loads the registry, local provider, and consumer by default so stdio and ACP apps get the same behavior while embedded or remote providers contribute skills without changing the registry or consumer. Its `skills` config forwards `registry`, `local`, and `tool` branches to those owners.
+`@deepseek-ai/dsh-skill` is the pure provider registry (`ctx.skills`), `@deepseek-ai/dsh-skill-local` is the shipped local filesystem provider, and `@deepseek-ai/dsh-tool-skill` owns the session-prefix catalog and model-facing loader tool. `dsh-agent-spine-demo` loads the registry, local provider, and consumer by default so stdio and ACP apps get the same behavior while embedded or remote providers contribute skills without changing the registry or consumer. Its `skills` config forwards `registry`, `local`, and `tool` branches to those owners.
 
-Provider plugins register synchronously during `apply()`. Provider catalogs return ranked candidates from awaited `list()` calls, where remote providers perform initialization, authentication, and discovery while honoring the lookup abort signal. The registry validates each candidate, resolves same-name skills first-wins by rank, provider registration order, and provider-local order, then sorts summaries by skill name for deterministic consumers. It caches only completed catalog snapshots and retries when a provider/runtime revision changes during discovery, so an unload cannot freeze a stale, unresolvable skill into a session prefix. Runtime `ctx.skills.register(...)` remains a convenience for embedded in-process skills and uses project-over-user priority; `runtime` is reserved as the registry-owned provider name.
+Provider plugins register synchronously during `apply()`. Provider membership is direct effect-owned state: registration and disposal invalidate completed catalogs synchronously, and discovery reads the current provider map on demand rather than observing registry-change events. Provider catalogs return ranked candidates from awaited `list()` calls, where remote providers perform initialization, authentication, and discovery while honoring the lookup abort signal. The registry validates each candidate, resolves same-name skills first-wins by rank, provider registration order, and provider-local order, then sorts summaries by skill name for deterministic consumers. It caches only completed catalog snapshots and retries when a provider/runtime revision changes during discovery, so an unload cannot freeze a stale, unresolvable skill into a session prefix. Runtime `ctx.skills.register(...)` remains a convenience for embedded in-process skills and uses project-over-user priority; `runtime` is reserved as the registry-owned provider name.
 
 The local provider scans cwd-sensitive project roots, custom roots, and user roots in first-wins rank order: project `.dsh`, project `.agents`, `customSkillDirs`, user `.dsh`, then user `.agents`. The user `.dsh/skills` scan skips `.system` so a system-owned directory is not treated as normal user content. DeepSeek Harness does not ship built-in system skills; embedded or remote providers supply additional skills when configured.
 

docs/rfc/implemented/feature/2026-07-06-approval-seam.md

@@ -23,7 +23,7 @@ One `cordis.yml` entry mounts the seam. Not loading it is the fail-closed opt-ou
   #   policy: never   # deployment default for sessions without an override; 'ask' when omitted
 ```
 
-The entry alone provides mechanism, not a channel: with no answerer composed, every ask resolves `unavailable` and the asking tool call denies — fail-closed needs no configuration. Composing the ACP app (`@deepseek-ai/dsh-acp-agent`, as in [the acp-agent example's default tree](../../../../examples/acp-agent/README.md)) completes the loop: its bridge registers an answerer that prompts the owning editor session via `session/request_permission`, so a hook's `ask` or an escalation request surfaces as a one-shot Allow/Reject prompt attached to the already-streamed tool call. `policy: never` is the unattended stance — every ask auto-rejects deterministically, stated in the system prompt, no human in the loop. `policy` is validated against the closed list at plugin load; anything else throws.
+The entry alone provides mechanism, not a channel: with no answerer composed, every ask resolves `unavailable` and the asking tool call denies — fail-closed needs no configuration. Composing the ACP app (`@deepseek-ai/dsh-acp-demo`, as in [the acp-agent example's default tree](../../../../examples/acp-agent/README.md)) completes the loop: its bridge registers an answerer that prompts the owning editor session via `session/request_permission`, so a hook's `ask` or an escalation request surfaces as a one-shot Allow/Reject prompt attached to the already-streamed tool call. `policy: never` is the unattended stance — every ask auto-rejects deterministically, stated in the system prompt, no human in the loop. `policy` is validated against the closed list at plugin load; anything else throws.
 
 What a composed deployment observes: `allowed-once` lets exactly that call proceed; rejection, dismissal, and channel absence deny with three distinct reasons the model can tell apart; every ask lands a durable `approval/asked`/`approval/decided` pair on the asking agent's session log; nothing about a grant persists past the call that asked.
 

docs/rfc/implemented/feature/2026-07-06-explicit-tool-order.md

@@ -21,7 +21,7 @@ The system-prompt assembly owns the canonical model-facing tool order, exactly w
 
 Scope is deliberately narrow: this fixes the REGISTRATION-ORDER race, not plugin behavior. A `system-prompt/assemble` listener may still add, remove, or rearrange tools — same as it may edit sections after their sort — and owns the determinism of what it emits; the waterfall contract already demands deterministic listeners (the reconstructability invariant would catch a listener that diverges between build and replay).
 
-Config plumbing follows the `persona` precedent, and `toolOrder` sits beside it: the app configs (`dsh-stdio-agent`, `dsh-acp-agent`) accept the key and forward it through `dsh-agent-core` (whose schema is the intersection of the owners' schemas) to the `SystemPrompt` child. One schemastery footnote is load-bearing: a schemastery array defaults to `[]`, but an omitted `toolOrder` must stay ABSENT (= lexicographic) rather than become an explicitly-configured empty list (invalid — it lacks the rest entry), so every schema on the chain forces the default to `undefined`.
+Config plumbing follows the `persona` precedent, and `toolOrder` sits beside it: the app configs (`dsh-stdio-demo`, `dsh-acp-demo`) accept the key and forward it through `dsh-agent-spine-demo` (whose schema is the intersection of the owners' schemas) to the `SystemPrompt` child. One schemastery footnote is load-bearing: a schemastery array defaults to `[]`, but an omitted `toolOrder` must stay ABSENT (= lexicographic) rather than become an explicitly-configured empty list (invalid — it lacks the rest entry), so every schema on the chain forces the default to `undefined`.
 
 ## Alternatives considered
 

docs/rfc/implemented/feature/2026-07-06-sandbox.md

@@ -70,7 +70,7 @@ Backend profiles share the mode contract but differ in necessary host grants. La
 
 #### The bash consumer
 
-`dsh-bash-sandbox` reuses local process execution and asks `ctx.sandbox` to wrap the exact bash argv. A kernel denial is a result fact independent of exit status and is inferred only from the selected wrap's stderr dialect. Runner failure outranks denial because it means the command never ran: foreground calls throw `SANDBOX_UNAVAILABLE`, while settled background tasks set `sandbox.runnerFailed` for `bash_output`. This keeps broken confinement distinct from both task failure and an enforced denial.
+`dsh-bash-sandbox` extends `LocalBashExecutor` and hands `ctx.sandbox` the exact `['bash', '-c', command]` argv it is about to spawn. A denial is an orthogonal result fact, conservatively classified from the active runner's stderr dialect. A runner failure outranks denial: foreground execution throws `SANDBOX_UNAVAILABLE`; a settled `BashProcess` stamps `sandbox.runnerFailed`, and the bash producer renders it through generic `task_output`.
 
 The model's view is result facts only: the static tool description explains the denial marker (`[sandbox: file access denied under <mode> mode]`), encourages attempting commands that may be denied, and forbids retrying around a denial; when the escalation fields are advertised, a denied result additionally carries the escalation hint itself, so the sanctioned same-turn retry is prompted at the decision point rather than depending on the model recalling the description (§ Escalation). No prompt section states the sandbox mode (§ Per-session modes).
 
@@ -78,13 +78,13 @@ The model's view is result facts only: the static tool description explains the
 
 `BashExecRequest.sandboxMode` is an optional per-call input; resolved specs make the field explicit. `BashExecutor.sandboxMode` advertises whether the mounted executor can honor it, so only a confining composition exposes escalation. The seam accepts any explicit mode; the tool owns the wider-only escalation rule. Non-sandboxing executors remain honestly unconfined.
 
-`SandboxBashExecutor.resolve()` stamps the effective mode — escalation grant > session override > configured default — so `run()`/`start()` read the spec, never the config. The `danger-full-access` branch, the confine call, and the result facts all key off the spec's mode, and the per-task facts map carries each task's mode alongside its wrap facts (`notifyTaskDone()` stamps from the map entry): one escalated call — foreground or background — reports the mode it ACTUALLY ran under while every neighbor keeps its own.
+`SandboxBashExecutor.resolve()` stamps the effective mode — escalation grant > session override > configured default — so `run()`/`start()` read the spec, never the config. Per-process wrap facts are keyed by the returned `BashProcess`; `onProcessDone()` classifies stderr and stamps that handle before `done` resolves, so overlapping processes retain their own modes and runner dialects.
 
 When a confining executor is mounted, `bash` advertises paired `sandbox_permissions` and `justification` fields. The schema exposes the full closed escalation vocabulary because effective mode is per-session; execution rejects any target that is not strictly wider than that call's effective mode. Approval resolves before execution. `allowed-once` stamps the granted mode onto only that request, while `rejected`, `cancelled`, `unavailable`, a missing approval service, or a missing agent all fail closed with distinct results. No grant is persisted.
 
 Escalation is a same-turn retry of the denied command with the narrowest sufficient `sandbox_permissions` and a `justification`; the approval prompt is the consent step. It must be grounded in an actual denial, except when the session already observed the same denied access, and a disabled or rejected approval ends that command. The retry, approval decision, and result use existing tool and approval events. `dsh-tool-bash` owns the ask because the executor seam has neither the agent nor call id required for user interaction.
 
-Left open, recorded for the phase that picks them up: what a grant's scope identity is beyond the sandbox mode — the exact call, a path, a command prefix, the session, a time window — the question `allow_always` grant storage must answer before that option can be advertised; and how escalation is defined for `run_in_background` denials that arrive via `bash_output`.
+Left open: what a durable grant's scope identity is beyond the sandbox mode — exact call, path, command prefix, session, or time window — before an `allow_always` option can be advertised.
 
 #### Per-session modes: the session log as the store
 
@@ -194,8 +194,8 @@ Costs and accepted limits:
 - **`bwrap` is installed on my host but unusable (disabled unprivileged userns, an LSM denying `mount`) — what happens?** The chain probe is functional — it builds and enforces a real profile rather than checking `--version` — so a present-but-unusable `bwrap` fails its probe, selection falls to the registry-installed Landlock launcher, and the verdict is cached for the provider's lifetime.
 - **Does the sandbox restrict network or process visibility?** No — `SandboxMode` claims FILE effects only; the bwrap profile deliberately does not unshare pid, and no backend claims network. Whether network restriction becomes its own knob is left open in § The seam.
 - **Which tools actually run confined?** OS subprocesses through `ctx.bash` — the bash tools, and hook commands transitively. fs/web/todo execute in-process, where an `execve` wrapper is mechanically meaningless; their `read-only` semantics arrive with the cross-family deferred phase, and until then the contract says bash-only honestly.
-- **Does a granted escalation persist, or cover background tasks?** Neither: the grant is consumed by the very call that asked (foreground or background), that one call reports the mode it actually ran under, and every neighbor keeps its own. How escalation should be DEFINED for a background denial that only surfaces later via `bash_output` is left open in § Escalation.
-- **When does an editor's mode switch take effect?** Mid-turn: appended immediately, honored by the very next call's stamp. Idle: held on the bridge's session record, anchored at the next `agent/prompt-submit` inside its open turn, with N flips coalescing to at most one event (none if net-zero); a crash before anchoring reverts it and `session/load` reports the truth. The model is not told — its next command simply behaves under the new mode.
+- **Does a granted escalation persist?** No. The grant is consumed by the exact foreground or background call that asked; every neighboring call keeps its own effective mode. A later background denial surfaces through `task_output` and may ground a new exact-command retry.
+- **When does an editor's mode switch take effect?** Mid-turn: appended immediately, honored by the very next call's stamp. Idle: held on the bridge's session record, anchored at the next turn's `agent/prompt-submit`, with N flips coalescing to at most one event (none if net-zero); a crash before anchoring reverts it and `session/load` reports the truth. The model is not told — its next command simply behaves under the new mode.
 - **What survives a restart — and what if the operator changed the config default while the process was down?** Overrides replay from the session log (`effective = fold ?? config`), so a resumed session keeps its modes with zero catch-up machinery; a default that drifted offline changes behavior the same way a switch does (the approval policy, being stated, is additionally narrated with operator/config attribution).
 - **What does `enforcement: 'partial'` on a result mean?** The selected backend enforces the subset its kernel ABI governs — e.g. Landlock before ABI v3 does not govern path truncate — and says so structurally instead of refusing the host; the probe's report line distinguishes the cases. The bwrap and Seatbelt profiles govern every promised file effect by construction, so they always report `full`.
 
@@ -204,7 +204,7 @@ Costs and accepted limits:
 In-repo precedents this design copies or contrasts with:
 
 - [The capability-seams RFC](../architecture/2026-06-13-capability-seams.md) — the interface/implementation/consumer split and the "don't split preemptively" timing rule the second consumer satisfied.
-- The `dsh-bash` request/spec split and its `owner` field ([the bash vocabulary catalog](../../../core-data-structures/bash.md)) — the per-call carrier template `sandboxMode` rides, and the explicit-`resolve()` defaulting convention.
+- The `dsh-bash` request/spec split ([the bash vocabulary catalog](../../../core-data-structures/bash.md)) — the per-call carrier template `sandboxMode` rides, and the explicit-`resolve()` defaulting convention.
 - [The approval seam RFC](2026-07-06-approval-seam.md) — the channel escalation asks through; its answerer waterfall, audit pair, and one-package rationale are recorded there.
 - [Event-sourced sessions](../architecture/2026-06-11-event-sourced-sessions.md) and [the turn-enclosure invariant](../architecture/2026-06-15-turn-enclosure-invariant.md) — the log-as-store foundation the per-session modes fold over, and the commit boundary the anchoring design obeys.
 - [The interception-seams RFC](2026-06-30-interception-seams.md) — the `tools/pre-execute` vocabulary the escalation gate deliberately does not reuse (an escalating call has no pre-execute moment of its own).

docs/rfc/implemented/feature/2026-07-07-mcp-client-plugin.md

@@ -0,0 +1,212 @@
+# RFC: MCP client plugin — connect to external MCP servers and bridge their tools
+
+Status: implemented
+
+## Problem
+
+The harness had no way to consume tools from the MCP (Model Context Protocol) ecosystem. MCP is the emerging standard for tool servers — GitHub, filesystem, databases, code search, and hundreds of community servers expose tools via MCP. Users want to point the harness at one or more MCP servers and have their tools appear as native model-facing tools, without writing per-server glue code.
+
+The `ToolRegistry` already accepts raw JSON Schema tool definitions (documented in `dsh-tools` README: "Raw JSON-Schema tool definitions (from MCP servers) are still accepted by `ToolRegistry.register()` directly"), and the extension cookbook sketches the intended pattern ("MCP | one plugin per server: discover tools → `ctx.tools.register()`"). The infrastructure was ready; the bridge plugin was missing.
+
+## Decision
+
+### Package
+
+A single package `@deepseek-ai/dsh-mcp-client` at `packages/mcp/mcp-client/`. No capability-seam three-package split — there is no foreseeable second MCP client implementation, and the convention is "don't split preemptively" ([capability seams RFC](../../implemented/architecture/2026-06-13-capability-seams.md)).
+
+### SDK
+
+Use the official [`@modelcontextprotocol/sdk`](https://github.com/modelcontextprotocol/typescript-sdk) (`Client`, `StdioClientTransport`, `StreamableHTTPClientTransport`). The harness does not implement its own JSON-RPC — consistent with how ACP delegates to `@agentclientprotocol/sdk`.
+
+### Scope
+
+MCP Client only (no server side — ACP already covers the "expose harness as an agent" role). Bridge **Tools** only — Resources and Prompts are deferred (they require harness-side consumption mechanisms that don't exist yet, and design space is large).
+
+### Plugin shape
+
+Namespace plugin (named exports `name`/`inject`/`Config`/`apply`, no `export default`). `inject: ['tools']`. Each MCP server is one plugin instance in `cordis.yml` — the same package loaded N times with different configs, like `dsh-tool-subagent`.
+
+### Configuration
+
+Flat discriminated union on the `transport` field:
+
+```typescript
+interface StdioConfig {
+  transport: 'stdio'
+  serverName: string          // required namespace, ^[A-Za-z0-9_-]{1,32}$
+  command: string
+  args?: string[]
+  env?: Record<string, string>
+  cwd?: string
+  toolCallTimeoutMs?: number  // default 60_000
+}
+
+interface StreamableHttpConfig {
+  transport: 'streamable-http'
+  serverName: string          // required namespace, ^[A-Za-z0-9_-]{1,32}$
+  url: string
+  headers?: Record<string, string>
+  toolCallTimeoutMs?: number  // default 60_000
+}
+
+type Config = StdioConfig | StreamableHttpConfig
+```
+
+`serverName` is the stable local identity that namespaces this server's tools in the model-facing name (below). It is deliberately user configuration, NOT the remote `serverInfo.name`: the remote name is untrusted input, is not unique across deployments (prod and staging instances of one server report the same name), and may change on server upgrade — none of which may silently rename model-facing tools. A duplicate `serverName` across live instances is a configuration error: the later instance fails at load with an actionable message, never silent shadowing or skipping. A short `serverName` (`gh`) is also the knob for shortening public names.
+
+Example `cordis.yml` usage:
+
+```yaml
+- id: mcp-github
+  name: '@deepseek-ai/dsh-mcp-client'
+  config:
+    serverName: github
+    transport: stdio
+    command: npx
+    args: ['-y', '@modelcontextprotocol/server-github']
+    env:
+      GITHUB_TOKEN: !!js process.env.GITHUB_TOKEN
+
+- id: mcp-web
+  name: '@deepseek-ai/dsh-mcp-client'
+  config:
+    serverName: web
+    transport: streamable-http
+    url: http://localhost:3000/mcp
+    headers:
+      Authorization: !!js `Bearer ${process.env.MCP_TOKEN}`
+```
+
+The model sees `mcp__github__create_issue`, `mcp__github__search_code`, `mcp__web__search`.
+
+### Lifecycle
+
+Boot-time from `cordis.yml`. HMR (`@cordisjs/plugin-hmr`) provides hot-swap: editing the yml entry triggers dispose of the old instance (disconnects, unregisters tools) and creation of a new one (connects, discovers, registers). No runtime-dynamic API for now. Public names are pure functions of `(serverName, rawName)`, so an HMR swap that keeps `serverName` recreates identical model-facing names — session history and permission rules stay valid — and adding or removing an unrelated server never renames an existing tool.
+
+### Tool discovery and registration
+
+Every MCP tool has two names:
+
+- `rawName` — the exact MCP `Tool.name`, used only on the wire (`tools/call`).
+- `publicName` — the globally unique model-facing name registered in the `ToolRegistry`:
+
+      mcp__<serverName>__<rawName>
+
+This server-qualified shape is the de-facto standard among multi-server agent clients — every surveyed end-user product qualifies MCP tools by server ([Claude Code](https://code.claude.com/docs/en/agent-sdk/mcp#tool-naming-convention) `mcp__github__list_issues`, [Codex](https://openai.com/index/unrolling-the-codex-agent-loop/) `mcp__weather__get-forecast`, [Gemini CLI](https://geminicli.com/docs/tools/mcp-server/#3-tool-naming-and-namespaces), [VS Code](https://github.com/microsoft/vscode/blob/ab9ec62c6a61e429a9abd612ff220c3f4834c9ea/src/vs/workbench/contrib/mcp/common/mcpServer.ts#L217-L260), [Cline](https://github.com/cline/cline/blob/52fdbb1d72f7324a28142a7ba7678d4b53c902f4/sdk/packages/core/src/extensions/mcp/name-transform.ts#L20-L35), [Roo Code](https://github.com/RooCodeInc/Roo-Code/blob/b867ec9145750d0ae1ff7f02d35406e9bf2a0b16/src/utils/mcp-name.ts#L117-L140), [Goose](https://github.com/block/goose/blob/b3a012cbdde854b0fe14f95b1c48543bf6517c0a/crates/goose/src/agents/extension_manager.rs#L1391-L1441), [OpenCode](https://github.com/anomalyco/opencode/blob/d199b1bff90282a4f9cd6251b5fc7b16875a52f6/packages/opencode/src/mcp/catalog.ts#L117-L120)); the exact `mcp__<server>__<tool>` spelling follows Claude Code and Codex. The `mcp__` marker keeps MCP registrations out of the native tools' namespace and gives permission/telemetry rules a stable shape (`mcp__*`, `mcp__github__*`).
+
+1. On connect: drain `client.listTools()` pagination, derive every tool's `publicName`, then register each as a raw `ToolDefinition` via `ctx.tools.register()`. The MCP JSON Schema and description pass through unchanged (no `defineTool` DSL conversion); only the model-facing `name` is replaced.
+2. Listen for `notifications/tools/list_changed` → re-run the same sync (dispose previous generation, register new). Deterministic names mean unchanged tools keep their names across re-syncs.
+3. The executor closes over `rawName`; the public name is never sent to the server and never parsed to recover the raw name.
+4. No `presentCall`/`presentResult` — the ACP bridge's generic-card fallback handles rendering.
+5. Tools are transparent in the system prompt — no "[via MCP]" annotation beyond the name itself.
+
+### Public name normalization
+
+MCP allows tool names up to 128 characters including `.`; the DeepSeek function-name contract allows `[A-Za-z0-9_-]` and at most 64. Public names are normalized deterministically: invalid characters become `_`, and when replacement or truncation changed the name, a 12-hex-char SHA-256 hash of the `(serverName, rawName)` identity is appended so distinct MCP identities can never collapse into the same public name:
+
+```typescript
+function publicToolName(serverName: string, rawName: string): string {
+  const joined = `mcp__${serverName}__${rawName}`
+  const normalized = joined.replace(/[^A-Za-z0-9_-]/g, '_')
+  if (normalized === joined && normalized.length <= 64) return normalized
+  const hash = sha256(`${serverName}\0${rawName}`).slice(0, 12)
+  return `${normalized.slice(0, 64 - 13)}_${hash}`
+}
+```
+
+### Name conflict handling
+
+MCP guarantees tool-name uniqueness only [within one server](https://modelcontextprotocol.io/specification/2025-11-25/server/tools#tool-names); cross-server collisions are the norm, not the exception (a [Microsoft Research survey](https://www.microsoft.com/en-us/research/blog/tool-space-interference-in-the-mcp-era-designing-for-agent-compatibility-at-scale/#namespacing-issues-and-naming-ambiguity) of 1,470 servers found 775 colliding tool names; `search` alone appears in 32 servers, and the official GitHub server publishes bare `create_issue`). The always-on namespace makes collisions structurally impossible instead of handling them at collision time:
+
+- Two servers publishing `search` coexist as `mcp__github__search` and `mcp__web__search`.
+- A native harness tool named `search` is unaffected.
+- Duplicate `serverName` config fails the later instance at load (see Configuration).
+- A server listing the same tool name twice is an invalid tool list: the sync throws and the previous generation stays registered.
+- A registry conflict during the swap can only mean a foreign tool squats on this server's `mcp__<serverName>__` namespace: the partial generation is rolled back (zero tools from this server) and the error is logged loudly.
+
+Tools are never silently skipped; which tools are available never depends on plugin load order.
+
+### Naming invariants
+
+1. Every MCP tool has the stable identity `(serverName, rawName)`; every active identity has exactly one public name.
+2. Public names are deterministic, globally unique, and satisfy the DeepSeek 64-char `[A-Za-z0-9_-]` contract.
+3. MCP `tools/call` always receives the original raw name.
+4. Connecting, disconnecting, or re-syncing an unrelated server never renames an existing tool.
+5. Registration order never determines which tool is available.
+
+### Tool execution
+
+A unified `execute` handler for all tools from one MCP server:
+
+1. Resolve `rawName` (the executor closes over it) and call `client.callTool({ name: rawName, arguments }, { signal: exec.signal })` with the configured timeout — the public name is never sent to the server.
+2. Map the result:
+   - Multiple `text` content blocks → join with `'\n'` into a single `TextBlock` (required: `flattenText` uses `join('')` without separator, so multiple blocks would lose inter-block boundaries).
+   - `image` content blocks → discard with a `ctx.logger.warn` (the harness has no image content block type; [drop-image RFC](../../implemented/simplification/2026-07-04-drop-image-content-block.md)).
+   - `isError: true` → map to the harness `isError` result path (`{ content: [...], isError: true }`).
+3. Cancellation: `exec.signal` (from the agent loop's cancel) is passed through to the MCP SDK's `callTool`, which sends `$/cancelRequest` to the server.
+
+### Subprocess environment (stdio transport)
+
+Replicate the `buildChildEnv` + `SENSITIVE_ENV_PATTERN` scrub from `dsh-subagent-acp`: filter ambient env (strip credential-shaped vars matching `/KEY|SECRET|TOKEN/i`), then merge `config.env` on top. Explicit env overrides survive the scrub.
+
+### Disconnection / crash
+
+No auto-reconnect. If the MCP server process exits or the transport closes:
+
+1. The effect disposes → all registered tools are unregistered (fiber-scoped disposers).
+2. Subsequent model calls to those tools → `ToolNotFoundError` → `isError: true`.
+3. Recovery: user edits `cordis.yml` (triggers HMR reload) or restarts the harness.
+
+This matches the ACP subagent pattern: "crash = terminal, report error, clean up, don't retry."
+
+## Alternatives considered
+
+### MCP Server side (expose harness tools to external MCP clients)
+
+Deferred. The ACP bridge already exposes the harness as an agent server. Adding an MCP server layer would duplicate that with a different protocol, and the primary user need is consuming external tools, not exposing them.
+
+### Capability-seam three-package split (interface / impl / consumer)
+
+Rejected. There is no foreseeable alternative MCP client implementation — MCP has one protocol, one SDK. The convention is "don't split preemptively" until a second implementation appears.
+
+### Auto-reconnect with exponential backoff
+
+Rejected for v1. Adds complexity (partial-availability state where tools are registered but temporarily non-functional), and stdio process crashes usually indicate a configuration problem that retrying won't fix. HMR already provides the manual recovery path. Can be added as a future `reconnect: boolean` config if needed.
+
+### Bridge Resources and Prompts
+
+Deferred. Resources need a harness-side mechanism to decide WHEN to inject content (system prompt? on demand? model-triggered?). Prompts need a "prompt template" concept the harness lacks. Both require their own design; Tools are the high-value, low-risk starting point.
+
+### Raw model-facing tool names with an optional `toolPrefix`
+
+Rejected — this was the original proposal, built on the premise that "most MCP servers already use semantic prefixes in their tool names (e.g. `github_create_issue`)". The premise is false: the official GitHub server publishes `create_issue`, the reference filesystem server `read_file`, Sentry `search_issues` — and the Microsoft survey above shows collisions are common at ecosystem scale. Collision-time prefixing (or warn-and-skip) also makes the available tool set depend on plugin load order, and a tool could be silently renamed when an unrelated server is added — invalidating session history and permission rules mid-conversation. No surveyed multi-server agent product ships raw names.
+
+### Server-only namespace (`github__create_issue`, no `mcp__` marker)
+
+Rejected for v1. It prevents cross-server collisions but does not separate MCP registrations from native harness tools, and it forfeits MCP-wide policy shapes (`mcp__*`). The marker costs 5 characters; the `mcp__<server>__<tool>` spelling matches Claude Code and Codex, maximizing model familiarity. If the ToolRegistry later grows source-aware namespaces, dropping the literal marker can be revisited as a naming-policy change.
+
+### Deriving the namespace from the server-announced `serverInfo.name`
+
+Rejected. The remote name is untrusted, non-unique across deployments, and changeable on upgrade; tool identity and permission rules must not silently follow it. The namespace is local configuration.
+
+### Preserve multiple TextBlocks in tool result
+
+Rejected. `flattenText()` in the DeepSeek serializer uses `join('')` (no separator) when flattening `ContentBlock[]` to wire format. Multiple text blocks would silently lose inter-block boundaries — a correctness bug. All existing tools return a single TextBlock; the MCP bridge follows suit.
+
+## Testing
+
+Coverage is named per tier; each behavior lives at the cheapest tier that can express it.
+
+- **Unit** (`tests/mcp-client.spec.ts`, `tests/apply.spec.ts`, mocked MCP SDK): the `publicToolName` algorithm (clean, normalize, truncate-and-hash, determinism, distinct-identity separation), raw-vs-public wire discipline, cross-server and native-tool coexistence, duplicate-`serverName` load failure and reservation release, invalid-tool-list rejection, generation swap/rollback, failed-re-sync retention, result mapping, cancellation, config schema validation. 100% per-file coverage gates the package.
+- **E2E** (`tests/mcp-client.e2e.ts`, keyless): the real MCP protocol against the in-repo fixture server, `@modelcontextprotocol/server-everything`, and `@modelcontextprotocol/server-filesystem` over stdio, and against an in-process `StreamableHTTPServerTransport` server over Streamable HTTP — discovery under the namespace, dotted-name normalization end to end, execution round-trips, duplicate-`serverName` rejection, disposal.
+- **Snapshot**: deliberately none. MCP tools introduce no new transcript surface — they register as raw `ToolDefinition`s and render through the ACP bridge's generic-card fallback, which the bridge's unit suite already pins (`packages/ui/acp/tests/stream-update.spec.ts`). Adding an MCP server to the snapshot example's `cordis.yml` would mutate the pinned `text-turn` system-prompt fixture (forcing a with-key re-record of every recorded golden) and make every replay depend on spawning an external MCP server process — for zero new rendering behavior. If a later change gives MCP tools their own render intent, that change names its snapshot coverage then.
+
+## Consequences
+
+- A `cordis.yml` entry per MCP server is the entire integration cost: `serverName: filesystem` + a stdio command (or a Streamable HTTP URL) puts `mcp__filesystem__read_file` in the model's tool list, callable, with the raw `read_file` on the wire.
+- Public names are part of session history and permission/config surfaces; the naming algorithm is a v1 contract pinned by tests, and changing it after release is a breaking change.
+- The `mcp__<serverName>__` qualifier costs tokens on every name. Accepted: descriptions and JSON schemas dominate tool-definition tokens, and the qualifier buys stable identity, collision isolation, and MCP-wide policy shapes (`mcp__*`, `mcp__github__*`).
+- **MCP SDK stability**: the `@modelcontextprotocol/sdk` is still evolving; breaking changes require updating the bridge. The version is pinned, and the SDK is widely adopted (Claude Desktop, Cursor, VS Code) so breaking changes are unlikely to be silent.
+- **Tool schema quality**: MCP servers may expose poorly-described tools (vague descriptions, incomplete JSON schemas). The harness passes them through as-is — garbage-in-garbage-out; that is the server author's responsibility, not the bridge's.
+- **Stdio process management**: a misbehaving MCP server that ignores signals could wedge dispose. The Cordis fiber disposal has bounded quiescence; a stuck transport eventually times out at the framework level.
+- Crash recovery is manual (HMR edit or restart) — accepted for v1; a `reconnect` config remains open as future work.

docs/rfc/implemented/feature/2026-07-08-background-subagent-tasks.md

@@ -0,0 +1,62 @@
+# RFC: Background subagent tasks
+
+Status: implemented
+
+## Problem
+
+The [subagent seam](2026-06-21-subagent-capability-seam.md) returns a `SubagentRun`, but the model-facing tool originally collected every run synchronously. Independent, slow delegations therefore held the parent call open or ran serially.
+
+Subagents need the same start, collect, list, stop, ownership, notification, and cleanup behavior as other long-running tools without adopting process-stream semantics. The child session remains the detailed trace; the parent needs the final answer and task status. A background child also outlives its starting tool call, so its cancellation and owner-disposal contracts must be explicit.
+
+## Decision
+
+Each `dsh-tool-subagent` instance may expose `run_in_background`, controlled by `enableRunInBackground` and enabled by default. A disabled instance omits the parameter and rejects a forced background argument at execution. Provider selection remains deployment configuration, so one instance still registers one distinctly named tool for one provider.
+
+Background subagents use the [generic background task runtime](../architecture/2026-06-20-generic-long-running-tool-runtime.md). Collection, listing, cancellation, completion notices, and prompt guidance come from `task_output`, `task_list`, and `task_kill`; there are no subagent-specific companion tools.
+
+Foreground calls retain their synchronous contract: await provider startup and `run.result`, return final text only for `completed`, map other terminal reasons to an errored tool result, and always dispose the run before returning.
+
+For a background call, the tool validates the parent and refuses an already-aborted execution signal before calling `ctx.tasks.start()`. The task runtime preflights the control surface and owner cleanup before invoking the producer starter. That starter creates an independent `AbortController` and begins `ctx.subagents.start()`; after the id is returned, the tool-call signal no longer owns the child.
+
+The task registration maps the subagent seam as follows:
+
+- `kind` is `subagent`, `label` is the model-supplied description, and `owner` is the parent agent.
+- `cancel(reason?)` aborts the task-owned controller. The same signal covers pending provider startup and the ready child.
+- `done` awaits provider startup, the child result, and `run.dispose()`. Completed runs return final text, aborted runs become `killed`, and other stop reasons become `failed`. Startup, result, and disposal failures become failed outcomes rather than rejected task promises.
+- `readOutput` is absent. While live, `task_output` returns status only; after settlement, it returns final output idempotently. Intermediate child activity remains in the child session.
+
+## Lifecycle
+
+A background subagent belongs to its parent agent and is not durable across owner closure. The task runtime attaches cleanup to the exact owner's scope. Agent disposal cancels the task and awaits startup rollback or child disposal before `AgentHandle.dispose()` resolves, preventing leaked child agents and sessions.
+
+Completion notices target the exact owner captured at start. If owner teardown has already disposed the injection target, the notice is dropped; cleanup, not notification, is the lifecycle guarantee.
+
+## Model guidance
+
+The generic task prompt teaches the shared habit: retain ids, continue independent work instead of busy-polling, collect relevant tasks before answering, and kill irrelevant work. The subagent schema adds only that background mode returns a task id and that `task_output` collects the result. Authorization and owner cleanup enforce the runtime boundary independently of prompt compliance.
+
+## Alternatives considered
+
+### Subagent-specific wait, output, and stop tools
+
+Capability-specific tools would duplicate the task protocol, teach another collect-and-stop habit, and complicate multiple provider instances. The generic runtime provides the required behavior without changing the tool's one-provider-per-instance shape.
+
+### Survival after owner closure
+
+Survival requires persistent task state, child-session recovery, a late-result delivery channel, and policy for abandoned owners. Owner-scoped cleanup gives process-local work a clear lifetime. Durable jobs require a separate design.
+
+### No owner checks for isolated clients
+
+Agents and logs may be session-scoped, but the task registry and predictable ids are runtime-global. The generic owner fence therefore applies to subagents like every other producer.
+
+### Incremental child transcript output
+
+Streaming child history into the parent would blur the log boundary and make provider behavior diverge. This surface exposes final output only; richer observation belongs to session or UI tooling.
+
+## Testing
+
+Unit coverage pins stop-reason mapping, dispose-before-report behavior, startup and result failures, pre-aborted refusal, detachment from the starting call's signal, cancellation before and after provider readiness, collection through the real task tools, the no-surface preflight fence, missing-runtime failure, and per-instance schema gating. Snapshot coverage pins the model-facing schemas.
+
+## Consequences
+
+The parent can fan out slow delegations and collect them through the same task controls used by bash. Child work no longer occupies the starting tool call, but it can consume resources until collected, killed, or owner-disposed. Prompt guidance encourages collection; owner cleanup provides the hard lifetime boundary. Deployments that require synchronous delegation can disable background mode per tool instance.

docs/rfc/implemented/feature/2026-07-10-parallel-tool-call-execution.md

@@ -58,7 +58,7 @@ Any shared state touched during execution must be concurrency-safe. This include
 
 `maxParallelToolCalls` is a positive AgentLoop deployment cap shared by every agent the factory creates. It defaults to `10`; `1` preserves serial execution. Exact fields and defaults live in the generated [configuration catalog](../../../config-catalog.md).
 
-The shipped declarations are conservative. Web search, web fetch, filesystem read, and subagent calls opt in. Filesystem writes and edits, bash tools, workflow, user interaction, todo mutation, Code Mode, and Cordis mutation tools remain exclusive. Bash stays exclusive until its owning package supplies a proven input-sensitive classifier.
+The shipped declarations are conservative. Web search, web fetch, filesystem read, and foreground subagent calls opt in. Background subagent starts remain exclusive because they register parent-owned task state. Filesystem writes and edits, bash tools, workflow, user interaction, todo mutation, Code Mode, and Cordis mutation tools also remain exclusive. Bash stays exclusive until its owning package supplies a proven input-sensitive classifier.
 
 Filesystem read relies on a narrow recorder exception: its synchronous observation updates may settle out of order, but write and edit re-check the observed version before mutation, so stale state only produces `FS_STALE_VERSION`.
 

docs/rfc/implemented/feature/2026-07-14-time-context-plugin.i18n.yaml

@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# side as of the last confirmed-consistent state. Both languages carry equal authority;
+# after editing either side, bring the other along and re-record with:
+#   pnpm run verify-translation-pairing --write
+2026-07-14-time-context-plugin.md: 105bf53550f087fdefb1e6fe0ec493f8628d3e18
+2026-07-14-time-context-plugin.zh.md: 60e9004b1453e75e1bcd84870ad7f18d200a95d8

docs/rfc/implemented/feature/2026-07-14-time-context-plugin.md

@@ -0,0 +1,57 @@
+# RFC: Optional time-context plugin
+
+Status: implemented
+
+English | [中文](2026-07-14-time-context-plugin.zh.md)
+
+## Problem
+
+An agent request has no live clock unless a deployment puts one in prompt text or gives the model a query tool. Static text becomes stale, while a tool call adds overhead to ordinary reasoning about dates, deadlines, or idle time. Without elapsed time, the model cannot distinguish an immediate follow-up from one sent hours after the preceding message.
+
+Prompt assembly can derive both facts per step from durable session timestamps, and request-header logging can record the exact rendered value. Accumulating stale readings in conversation history or waking idle agents would violate the existing request lifecycle.
+
+## Decision
+
+`@deepseek-ai/dsh-time-context` is an opt-in function plugin at `packages/context/time-context/`. The `context/` product group holds bounded request-context enrichments that define neither a tool nor a service. `dsh-agent-spine-demo` and shipped examples do not load the package; deployments mount it explicitly when its token and disclosure costs are acceptable.
+
+The plugin registers the global `context:time` system-prompt section at order 10, after the deployment persona and before tool guidance. For an active turn it emits an ISO-shaped timestamp with numeric UTC offset and IANA zone, plus a compact whole-second duration since the last model-visible message before the turn opened. Bare and idle assemblies receive an empty section.
+
+### Previous-message baseline
+
+At a turn's first assembly, the provider scans before `turn/start` for the latest `user/message`, `assistant/message`, `tool/result`, `context/message`, or `steering/message`. It excludes the current prompt so the duration expresses the inter-turn gap instead of approximately zero. Every refresh in that turn keeps the same baseline, and the first turn reports `unavailable (no earlier message in this session)`.
+
+The baseline is the session event's append time, not an unlogged client timestamp. Resume and fork behavior are therefore deterministic from the durable log, and the model-visible value remains reconstructable without a new event. A backward wall-clock adjustment clamps the duration to zero.
+
+### Refresh policy
+
+`refreshIntervalMs` defaults to 60,000 and must be a non-negative safe integer. Every turn's first request refreshes. Later assemblies in that turn reuse the block until its age reaches the interval; `0` refreshes every step. No timer creates work during model calls, tools, or idle time because refresh is request-bound.
+
+When `timeZone` is omitted, `Intl.DateTimeFormat` resolves the Node process's system zone once at plugin load. Node honors `TZ`; without that override, the host or container supplies the zone. An explicit value must be an IANA identifier and is validated at load. The captured zone remains stable until plugin reload, and the ISO-shaped local timestamp includes its current numeric offset so daylight-saving changes stay explicit. This is the deployment process's zone, not a remote user's zone.
+
+### Logging and token shape
+
+The loop records the temporal block through `request/header` and `request/header-delta` before transmission, satisfying the [reconstructable-requests contract](../architecture/2026-07-05-reconstructable-requests.md). Each request carries one current block; earlier readings do not remain in conversation history. The plugin owns the fact and contributes it through the prompt registry, following the [prompt-variables RFC](../architecture/2026-07-05-prompt-variables-and-tool-guidance-ownership.md) without a loop special case.
+
+## Testing
+
+Unit tests pin formatting, baselines, refresh policy, validation, per-agent state, disposal, and load-time system-zone capture. A real agent-loop test pins the transmitted prompt and `request/header-delta`. A keyless subprocess e2e boots a test-only `cordis.yml` through the real Loader and stdio app, omits `timeZone` under a controlled `TZ`, drives two turns, and verifies the persisted request headers externally. Default snapshot compositions omit the plugin, so their transcript fixtures contain no temporal block.
+
+## Alternatives considered
+
+- **Append a `context/message` on every turn or refresh** — rejected because readings and token cost would accumulate in history. Replacing a prior surface node would preserve its old position, while replacing the tail would hide intervening conversation.
+- **Use `agent/session-prefix`** — rejected because the session-stable prefix cannot represent a per-turn or per-step clock.
+- **Mutate requests in `agent/request`** — rejected because that seam shapes call config after the message boundary; inserted model content would bypass prompt-pressure accounting and request-header logging.
+- **Register separate `{{current_time}}` and `{{elapsed}}` variables** — rejected because independent providers can sample different instants and require shared caching. One section records the pair atomically without a deployment-authored template.
+- **Refresh from a background timer** — rejected because a new value has no consumer outside request assembly. Timer-driven `agent.inject()` would create turns and wake idle sessions merely to report time passing.
+- **Keep UTC as the omitted default** — rejected because an explicitly enabled clock should follow its deployment environment unless the operator chooses UTC. `timeZone: UTC` remains available when a deployment requires it.
+- **Add a time-zone detection library** — rejected because Node's `Intl` runtime already exposes the process's IANA zone. Another dependency cannot infer a remote user's zone either.
+- **Mount the plugin in `dsh-agent-spine-demo`** — rejected because time zone, disclosure, token budget, and freshness are deployment policy. Opt-in keeps default context stable.
+- **Place the package in `core/`** — rejected because `core/` owns the product API spine, while this plugin is an optional leaf with no service key.
+
+## Consequences
+
+- Opted-in models receive a zoned clock and inter-turn duration without a tool call. The system-prompt cost is fixed per request instead of growing with the session.
+- An omitted `timeZone` follows the process's `TZ`, host, or container zone as observed at plugin load. Operators must configure an explicit zone when the deployment environment does not represent the intended user.
+- A refresh changes the request header and can add a `request/header-delta`. `refreshIntervalMs` trades freshness against durable deltas; `0` records a new value on every step whose whole-second rendering changes.
+- No request exists solely to refresh time. A long-running tool leaves the prior reading until the next step assembles.
+- Duration reflects harness processing time at durable append boundaries, not client-network latency before logging. Preserving a client-origin timestamp requires a separate durable input contract.

docs/rfc/implemented/feature/2026-07-14-time-context-plugin.zh.md

@@ -0,0 +1,57 @@
+# RFC：可选时间上下文插件
+
+Status: implemented
+
+[English](2026-07-14-time-context-plugin.md) | 中文
+
+## 问题
+
+如果部署方既未在提示词中提供时钟，也未给模型提供查询工具，agent（智能体）请求就无法获得实时准确的时间。静态文本会变得陈旧，而对于日期、截止时间或闲置时长等常规推理，调用工具会增加开销。缺少已经过去的时长时，模型无法区分紧接着发送的消息与上一条消息几小时后才发送的消息。
+
+提示词组装流程可以在每个步骤中根据持久会话时间戳派生这两项信息，请求头日志则可以记录实际渲染的确切值。在会话历史中累积陈旧读数或唤醒空闲 agent 都会违反现有请求生命周期。
+
+## 决策
+
+`@deepseek-ai/dsh-time-context` 是位于 `packages/context/time-context/`、需要显式启用的函数插件。`context/` 产品分组用于容纳既不定义工具、也不定义服务的有界请求上下文增强。`dsh-agent-spine-demo` 和仓库提供的示例都不会加载该 package；只有当 token 与信息披露成本可接受时，部署方才显式挂载它。
+
+该插件注册顺序值为 10 的全局系统提示词区段 `context:time`，位置在部署方角色设定之后、工具指导之前。对于活跃轮次，它会输出带数字 UTC 偏移和 IANA 时区、形似 ISO 的时间戳，以及从轮次开始前最后一条模型可见消息起算的紧凑整秒时长。未绑定 agent 或 agent 处于空闲状态时，该区段为空。
+
+### 上一条消息基线
+
+在轮次首次组装时，提供方会在 `turn/start` 之前查找最近的 `user/message`、`assistant/message`、`tool/result`、`context/message` 或 `steering/message`。它会排除当前提示词，使时长表达轮次间隔，而不是接近零。同一轮次中的每次刷新都保留这条基线；首个轮次报告 `unavailable (no earlier message in this session)`。
+
+基线采用会话事件的追加时间，而不是日志中不存在的客户端时间戳。因此，恢复和 fork 行为可以从持久日志中确定性重现，模型可见值也无需新增事件即可重建。系统挂钟向后调整时，插件会将时长钳制为零。
+
+### 刷新策略
+
+`refreshIntervalMs` 默认值为 60,000，并且必须是非负安全整数。每个轮次的首次请求都会刷新。同一轮次中的后续组装会复用该区块，直至其存在时间达到该间隔；设为 `0` 时每个步骤都刷新。刷新仅由请求驱动，因此在模型调用、工具运行或空闲期间，计时器不会创建任务。
+
+省略 `timeZone` 时，`Intl.DateTimeFormat` 会在插件加载时解析一次 Node 进程的系统时区。Node 会遵循 `TZ`；没有该覆盖值时，时区由主机或容器提供。显式值必须是 IANA 标识符，并在加载时接受校验。捕获的时区在插件重新加载前保持稳定，形似 ISO 的本地时间戳包含其当前数字偏移，使夏令时变化保持显式可见。该默认值代表部署进程的时区，而不是远程用户的时区。
+
+### 日志与 token 形态
+
+agent loop（智能体循环）会在发送前通过 `request/header` 和 `request/header-delta` 记录时间区块，从而满足[可重建请求契约](../architecture/2026-07-05-reconstructable-requests.md)。每个请求只携带一个当前区块；先前的读数不会保留在会话历史中。该插件拥有时间信息，并按照[提示词变量 RFC](../architecture/2026-07-05-prompt-variables-and-tool-guidance-ownership.md)通过提示词注册表贡献该信息，无需为循环添加特殊分支。
+
+## 测试
+
+单元测试固定格式化、基线、刷新策略、校验、逐 agent 状态、资源释放行为，以及系统时区在加载时的捕获行为。使用真实 agent loop 的测试固定实际发送的提示词和 `request/header-delta`。无密钥子进程端到端测试通过真实 Loader 和 stdio 应用启动测试专用 `cordis.yml`，在受控 `TZ` 下省略 `timeZone`，驱动两个轮次，并从外部校验持久请求头。默认快照组合不包含该插件，因此其中的 transcript（文本记录）fixture（测试前置数据）不包含时间区块。
+
+## 考虑过的替代方案
+
+- **每个轮次或每次刷新都追加一条 `context/message`**——不予采纳，因为读数和 token 成本会在历史中累积。替换先前的表层节点会保留其旧位置，而替换尾部节点会隐藏中间的会话内容。
+- **使用 `agent/session-prefix`**——不予采纳，因为会话期间保持稳定的前缀无法表示逐轮次或逐步骤变化的时钟。
+- **在 `agent/request` 中修改请求**——不予采纳，因为该边界在消息边界之后塑造调用配置；插入模型可见内容会绕过提示词压力核算和请求头日志。
+- **注册独立的 `{{current_time}}` 和 `{{elapsed}}` 变量**——不予采纳，因为独立提供方可能在不同时间点采样，并且需要共享缓存。单个区段会以原子方式记录两项信息，也不需要部署方编写时间模板。
+- **通过后台计时器刷新**——不予采纳，因为请求组装之外没有消费新值的对象。由计时器驱动 `agent.inject()` 会创建轮次，并且只为报告时间流逝就唤醒空闲会话。
+- **省略配置时仍默认使用 UTC**——不予采纳，因为显式启用的时钟应跟随部署环境，除非运维方选择 UTC。需要 UTC 的部署仍可配置 `timeZone: UTC`。
+- **引入时区探测库**——不予采纳，因为 Node 的 `Intl` 运行时已经能够提供进程的 IANA 时区，而且额外依赖同样无法推断远程用户的时区。
+- **在 `dsh-agent-spine-demo` 中挂载插件**——不予采纳，因为时区、信息披露、token 预算和新鲜度都属于部署策略。选择加入能保持默认上下文稳定。
+- **将 package 放入 `core/`**——不予采纳，因为 `core/` 负责产品 API 主干，而该插件是没有服务键的可选叶节点。
+
+## 后果
+
+- 选择加入的模型无需调用工具，即可获得分区时钟和轮次间隔时长。每个请求的系统提示词成本固定，不会随会话增长。
+- 省略 `timeZone` 时，插件采用加载时观察到的进程 `TZ`、主机或容器时区。当部署环境不能代表目标用户时，运维方必须显式配置时区。
+- 刷新会改变请求头，并可能新增 `request/header-delta`。`refreshIntervalMs` 用新鲜度换取持久增量记录的数量；设为 `0` 时，每个整秒渲染结果发生变化的步骤都会记录新值。
+- 系统不会仅为刷新时间而创建请求。长时间运行的工具会保留先前读数，直至下一步骤开始组装。
+- 时长反映持久追加边界处的 harness 处理时间，不包含消息进入日志之前的客户端网络延迟。若要保留客户端来源时间戳，需要单独的持久输入契约。