Tianyi Cui
140f818a42
Complete the boundary-mirror removal begun with the step mirrors: drop `agent/turn-start` and `agent/turn-end` from the agent event taxonomy. Turn and step boundaries are now read exclusively off the durable `session/event` feed (`turn/start`/`turn/end`/`step/start`/`step/end`) — there is no `agent/*` mirror for any boundary. - loop.ts: delete both turn emits; `closeTurn` loses its `emit` parameter and its now-unreachable idempotency guard (it is called exactly once per turn, on mutually exclusive normal/catch paths); `failTurn` loses the dead post-close branch that only a throwing turn-end LISTENER could reach. - ui-stdio: render turn boundaries from `session/event`, recovering the short agent label from an `agent/created`→id map (the `turn/start` event carries only the turn number, and the session id is not reliably the agent id). ui-stdio is a disposable test REPL, so this migration retires the sole justification the event-domain-semantics RFC gave for KEEPING the turn mirrors. - Tests: reason/turn-number collectors and the boundary-ordering test now read `session/event`; the throwing-turn-boundary-LISTENER tests are deleted (that code path no longer exists). A new test covers the outer-catch disposed branch via a pre-step listener that disposes-then-throws (the surviving real path). - Docs: promote the "remove agent boundary mirror events" RFC to implemented (amended/narrowed — `agent/steering` is RETAINED, not a boundary mirror); update the event-domain-semantics + turn-enclosure RFCs, architecture.md, the cookbook, the ACP/agent/ui-stdio prose, and regenerate the cordis catalog. `agent/steering` and `agent/stream-chunk` are explicitly out of scope (not durable-boundary mirrors). ACP is unaffected — it already settles from the log's `turn/end` + `agent/status`; snapshot goldens are byte-unchanged.
core/ — product API spine
The packages every harness build is assembled from: the session log, the system-prompt assembly, the tool registry, the agent vocabulary, and the one concrete loop that drives them. These are product packages — the stable surface plugins and consumers build against.
| Package | Role | ctx key |
|---|---|---|
session/ |
Event-sourced session log + in-memory store | ctx.sessions |
system-prompt/ |
Prompt-section + tool-schema assembly registry | ctx.systemPrompt |
tools/ |
Tool registry + tools/execute waterfall |
ctx.tools |
agent/ |
Agent interface, registry, agent/* event vocabulary |
ctx.agents |
agent-loop/ |
The concrete loop plugin: ReactLoopAgent + the loop driver |
ctx.agentLoop |
agent-core/ |
Bundle plugin: the providerless/executor-less/UI-less spine as code | (loads the spine) |
agent-loop is the one concrete implementation of the agent seam and lives here because it is the harness's default product loop; everything else in core/ is interface/vocabulary. Plugins depend on the agent vocabulary, never on agent-loop directly, so the loop stays swappable.
agent-core is the composition counterpart: one bundle plugin that loads the whole providerless spine (timer + llm + sessions + system-prompt + tools + agents + invariants + tool-bash + agent-loop) and forwards agent-loop's agents list as its own config. App packages (ui/stdio-agent, ui/acp-agent) consume it and add only a front door; a leaf adds the swappable backends plus any optional product tools it wants to expose. It lives in core/ because it composes exclusively core/ + interface packages and ships no provider, executor, or UI of its own.