The reconstructability RFC is the principle's home: model-visible ⟺
logged in both forms, the mechanism (boundary derivation + header
fold), the enforcement (write-time round-trip guard, the dev
invariant), the corollaries ranked (prefix-cache stability first), the
MiniCode lineage with the provenance arrow inverted, and the
alternatives it beat — including the stateful transmission client
whose three-design archaeology lives in PR #162.
Placements per the one-home-per-fact taxonomy: a standing-order line in
root AGENTS.md (with displacement trims to stay inside the 1,575-word
ceiling), the principle statement in architecture.md § Session Log and
its Turn Flow lines (condensed to the ratcheted 1,630 ceiling), the
request-envelope section in core-data-structures/core.md with the
LlmCallConfig paste, both review-requested FIXMEs
(FIXME(call-config-shape) beside the type, FIXME(catalog-verbs) at the
catalog's drift-gate note), cookbook rows redirected off agent/request
(tool filtering → system-prompt/assemble, plan-mode prompt → sections/
inject()), and the llm/stream JSDoc stating the frozen-request
contract. RFC index and all generated catalogs regenerated.
The loop is now transmission-stateless; a request is a pure function of
(session log, this step's rendered assembly, current AgentOptions):
- The reconstruction boundary is step/start: the messages snapshot is
taken in the same synchronous frame immediately before the step/start
append, so the request's messages are exactly the derivation over
events[0..stepStartSeq) — an inject() from an agent/request listener
(or any concurrent task) lands after the boundary and joins the NEXT
request. This changes behavior for a synchronous step/start
session/event listener that appends content (master derived after the
append, so such a listener could reach the current request):
agent/pre-step is the sanctioned seam for current-request content.
- agent/request is re-typed to config-only: (agent, turn, step,
config: LlmCallConfig, next) → LlmCallConfig. The frozen seed comes
from AgentOptions on a loop instance's first request (explicit options
beat the logged baseline — fork overrides and resume reconfiguration
stay correct) and from the log's folded header afterwards; listeners
return a replacement to switch. Content shaping through the request is
no longer expressible — model-visible content flows through the log
channels.
- recordRequestHeader appends whatever header event the request owes the
log before dispatch: an 'initial'/'resume' snapshot anchoring each
loop instance, a round-trip-verified delta on change, a 'fallback'
snapshot when the encoding cannot express it. Session.requestHeader()
is the log's incrementally-folded baseline.
- Requests are deep-frozen before dispatch (deepFreeze exempts the
AbortSignal — freezing one breaks AbortController.abort() outright);
frozen + sessionId is the loop-built marker the dev invariant keys on.
Ported from #162 and re-anchored on the log: the append-extension /
frozen-end-to-end / compaction-resend / prompt-change property tests,
plus new specs for the boundary semantics, resume anchoring, and the
end-to-end theorem (every recorded request rebuilds byte-equal from the
log alone). Live cache-hit e2e (request-cache.e2e.ts) verified against
the real DeepSeek API. Snapshot goldens intentionally stale until the
single re-record after the compact/summary envelope lands.
deriveMessages() no longer re-derives and re-clones the whole surface
per call: each node is projected exactly once, when first seen (O(new
nodes) per access), through the now-public deriveEventMessage — the
per-node pure function external reconstructors and the dev invariant
fold over a log prefix, so no two paths can disagree about a request's
messages. A surface rewrite (replace, invalidate) rebuilds, signalled
by SurfaceManager.replaceGeneration — monotonic, bumped by every folded
replace and by invalidate(), never reset. Callers get a fresh array
snapshot per call over SHARED deep-frozen messages: isolation of the
append-only log moves from per-call cloning to unrepresentability
(mutation throws), which the two isolation tests now pin directly.
Every conversation request's non-content half (system prompt, tool
schemas, call config — the EpochHeader) is now recorded in the session
log: a 'request/header' full snapshot (reason 'initial' | 'resume' |
'fallback') anchors the fold at conversation birth and process
boundaries, and 'request/header-delta' events (system line-trim,
name-keyed tools delta, whole config) encode mid-run changes. The pure
trio — foldRequestHeader / diffHeader / applyHeaderDelta — reconstructs
the header any request was built under from the log alone; the writer
contract round-trip-verifies every delta with a 'fallback' snapshot
when the encoding cannot express a change (pure tool reordering), so a
well-formed log always folds cleanly. Canonical absence: empty system
and empty tools normalize to absent fields, matching request builds.
Persistence and cordis catalogs regenerated; SessionEventMap paste and
EpochHeader added to the core-data-structures session page.
ds-review-bot round 2, both warnings:
- subagent/provider-removed now routes through emitLifecycle (per-listener
containment, the subagent/start|end precedent) instead of raw ctx.emit,
whose dispatch halts on the first throw: a throwing subscriber can no
longer starve a later mirror into keeping a stale tool, nor disrupt the
backend fiber's teardown mid-disposer. provider-added deliberately keeps
propagation (register-time rollback semantics, like the system-prompt
registries); the asymmetry is documented on emitLifecycle, the event
JSDoc, and the provider-lifecycle RFC.
- The documented model-via-agent/request fallback composes with a
{{model}} persona via the ownership rule itself: the plugin supplying
the model late states it early on the system-prompt/assemble waterfall.
Declined re-ordering render after agent/request — it would break the
agent/pre-step contract (compaction must measure the prompt the model
sees). New loop test pins the supply path end-to-end; the RFC's
{{model}} consequence bullet now covers supply as well as switch.
Review round 2 (tianyicui inline comments):
- dsh-system-prompt itself registers the harness:identity (-100) and
deployment:persona (0) sections — they must survive a swapped loop
plugin, so they leave dsh-agent-loop; the persona text is the plugin's
own validated 'persona' config. The model/cwd variables STAY on the
loop: runtime facts of the agents it drives.
- AgentOptions.systemPrompt is deleted with all its forwarding plumbing:
the app configs' systemPrompt keys become 'persona' routed through
dsh-agent-core (schema = z.intersect of the owners'), the ACP bridge
and tool-subagent stop carrying persona configuration, and subagent
children now render the deployment persona like every other agent.
- Example personas drop transport/interface trivia (ACP, CLI) — facts
irrelevant to the model.
- Root CONTEXT.md removed (not idiomatic); its persona definition was
wrong under the new ownership anyway.
- Docs, READMEs, the prompt-variables RFC, and generated catalogs
updated; new loop test pins the assemble-waterfall escape valve
(an emptied assembly sends NO system field).
Reconciliations beyond textual conflicts:
- product rename (DeepSeek Code -> DeepSeek Harness SDK) applied to the
PR-added assertion in system-prompt.spec.ts that master's rename
commit could not reach
- architecture.md: master's rewrite kept; this PR's prompt-assembly
semantics re-added in the new doc's voice (Turn Flow footnote +
service-spine row), within the 1630-word ceiling
- cordis catalog regenerated into master's split events.md/services.md
(events-and-services.md deleted); module graph and doc graphs
regenerated to pick up this PR's new events and dependency edges
Master split the cordis catalog (d55d4120) while this branch was in review.
Resolution: keep this branch's Service map restructure, adopt master's split
catalog link targets (events.md / services.md), and regenerate the catalog so
the waterfall-semantics anchor fix lands in the split output.
gen-cordis-catalog.ts now emits docs/cordis-catalog/events.md and
docs/cordis-catalog/services.md instead of the combined
events-and-services.md: a reader is either finding what to listen to or
what to call, and each axis now scans and deep-links as its own page.
Headings promote one level (scopes and ctx.<key> entries become H2), the
dispatch-mode legend lives on the events page, and the inherited tier
splits accordingly. --check verifies both files and names whichever is
stale.
Every reference updated in the same change (no compat redirects,
pre-release stance): architecture.md, AGENTS.md, docs/AGENTS.md tier row,
filesystem/subagent core-data-structures pages (the ctx.fs anchor
survives — slugs are heading-level-independent), fs README, four RFCs,
the tool-catalog and persistence-catalog generator intros (both
regenerated), and the bilingual development.md pair (re-recorded).
