The 2026-09 observability wave's type-level foundation, landed before the
streams so nothing renders against guessed shapes:
- contracts/chat.ts: CallUsage + TurnUsage (per-model-call token accounting,
one entry per teacher/wake turn keyed by messageId) and ChatRecord.turns —
a DELIBERATELY parallel append-only usage log, not per-message metadata:
the client re-POSTs its message list every turn and its copies never
carry server-stamped fields, so anything inside messages gets clobbered
by the next persist (the wave-3 merge-rule lesson).
- contracts/chat.ts: PlanBlockData — the persisted data-plan-block part
(full DAG on plan_init, one-level neighborhood on plan updates, snapshot
semantics so history renders what was true then).
- contracts/jobs.ts: JobUsage + JobRecord.usage — a sub-agent run's
accumulated accounting, written by the runner.
- core/ports.ts + store/chats.ts: ChatStore.appendTurnUsage — idempotent
per messageId (abort replays / wake retries append once); listChats no
longer leaks turns into the list payload.
- core/prices.ts: PRICES + CONTEXT_LIMITS (generated from OpenRouter's
published pricing via scripts/sync-pricing.ts) + pure folds: callCost,
turnCost, sessionCost, contextWindow, jobCost. Unknown model or absent
fields render as absent, never zero.
- server/observability.ts: barrel-approved surface for the transport layer
(fixes the import-law violation in the graph status route that slipped
through the wave-3 merge verification).
Capture wiring (agent onStepFinish -> persist seam, plan-block emission)
lands next as master seam work; the streams start against these shapes.
The teaching agent no longer runs on pi. Stack:
- ToolLoopAgent (ai@7) + OpenRouter (OPENROUTER_API_KEY), model via LH_MODEL,
default anthropic/claude-sonnet-4.5 with reasoning tokens
- quiz/ask_user_question = client-side tools (no server execute): the call
lands as a typed tool part in input-available state; the card grades via
src/core/question-core.ts; addToolOutput sends the verdict; the teacher's
reaction continues the same assistant message
- resume-mid-quiz is free: the pending tool part persists in the transcript
- persistence: one JSON per chat (data/chats/), full UIMessage transcripts,
saved onFinish (also on abort)
- UI: AI Elements (owned copy-paste components, pruned to the five in use)
+ button-based QuizCard/AnsweredCard (ask answers never graded)
- pi fully removed: TUI, extensions, Fastify+WS server, bridge, custom
protocol all deleted (recoverable from git history)
- tests: question-core units carry over; chat-flow integration drives
handleChatRequest with MockLanguageModelV4 (48 tests, zero tokens);
render smoke tests guard the cards (renderToStaticMarkup)
Carried over unchanged: teacher system prompt, question-core, schema/
ledger/derive/extract pipeline, data model.