The bug: answering a quiz and navigating away mid-turn, then returning,
re-prompted the same question. Root causes: (1) the answer was durable only
at onFinish — every mid-turn view read the stale pre-answer record;
(2) the server had no notion of a turn in flight; (3) remount treated the
stale record as current, with no re-attach path. Worse, the stale dock let
the quiz be answered again, racing two turns into a last-writer-wins
saveMessages clobber.
Fix (four pieces):
- Write-ahead persist in chat-handler: the request body IS the client's
canonical state — saved to disk BEFORE the stream starts. The answer is
durable the instant the request arrives; crashes recover via the existing
mount continuation.
- Turn liveness registry (src/server/turn-liveness.ts): in-memory chatId →
in-flight map with a TTL leak guard; beginTurn rejects concurrent turns
(409) so one turn ever owns a chat. endTurn runs in onFinish AFTER
persistTurn, so pollers that see not-in-flight always read a finished
record; a turn-start failure clears the registry (no lockout).
- GET /api/chats/[id] reports turnInFlight; the chat page passes
initiallyInFlight to the client.
- Client re-attach (components/chat.tsx): while in flight, busy shimmer +
composer gated + mount continuation suppressed; poll /api/chats/[id] until
the turn finishes, then syncFromServer adopts the completed transcript.
Stop stays local-stream only (a server turn has no client request to
abort).
Verified by scripted-model tests: concurrent turn 409 + registry lifecycle,
write-ahead durability mid-turn, failed-turn lockout guard.
quizInputSchema now enforces (via pure quizInputProblems + superRefine) that
correctAnswer resolves against option values, options are non-empty and
unique, and multi-answer requires multiSelect — schema-valid now implies
gradeable. The AI SDK already returns invalid tool input to the model as a
tool-error part (verified in ai@7 run loop), so the teacher retries in the
same turn. chat-handler onError passes tool-input validation messages
through to the client (masked 'An error occurred.' for everything else).
Covers the Gate 3 GLM failure: correctAnswer slug matching no option.
The knowledge graph's write channel is now the pivot's target
architecture (vision §1 construction):
- src/agent/subagents/extraction.ts — the pipeline factory
(createExtractionPipeline({ chatStore, graphStore, extractor?,
auditor? }); models env LH_EXTRACT_MODEL ?? LH_MODEL):
* transcriptView(): the compact view both LLM stages see — final plan
tree with node ids, conversation verbatim, QUIZ lines with outcomes,
mark_done lines; job tool parts are one-liners, plan ops fold into
the tree line.
* Extractor: transcript → SessionFindings (propositions incl.
misconceptions and prose-only supports edges, attribution for
UNTAGGED probes, all with verbatim evidence) via one zod-validated
submit_findings call.
* Auditor: transcript + findings → the verified subset + drops (the
faithfulness net) via submit_review.
- src/core/graph.ts — emitChat/foldStaleChats/replayFinalTree retire;
mergeFindings() replaces them as the pipeline's deterministic apply
stage: exact/alias identity resolution (one mapping line per (chat,
graph node)), edge dedupe, and event rebuild FROM THE TRANSCRIPT's tool
parts — kinds/timestamps/refs/notes deterministic, the LLM's only event
say being WHICH proposition an untagged probe tested (retroactive —
the vision's open question #3, resolved structurally: tagged events
resolve deterministically; attribution rescues untagged and
tagged-but-unmapped ones; unattributable land null + question text).
pendingQuizAnswers() is the trigger helper.
- Trigger (turn-service.ts triggerExtraction, replacing the old
foldTurnIntoGraph body): once a chat accumulates
EXTRACTION.everyNQuizAnswers (LH_EXTRACT_N, default 3) new answered
quizzes, fire the pipeline async — single-flight per chat, failure
checkpoints nothing and re-runs on the next trigger. Deliberately a v1
placeholder isolated in ONE seam, trigger-agnostic pipeline.
- GET /api/graph is now a pure read (foldStaleChats gone).
- NodeMapping.treeNodeId → sourceId (the mapping key is now the writer's
local proposition id — tree node when tree-derived); store strict-read
schema updated. Local ledger data regenerates through the pipeline.
- Tests: graph.test.ts rewritten around mergeFindings (identity,
attribution paths incl. ghost-rescue, idempotency, cross-session
provenance, trigger counting), graph-context.test.ts merge section
converted to findings-driven, NEW extraction.test.ts — transcriptView
units + the full pipeline with mock models (audit drops, failure
checkpoints nothing, single-flight). 195/195, tsc/eslint/build clean.
Probe attribution (vision open question): probes attach retroactively by
the extractor against the whole transcript; a pre-tree probe maps to a
proposition the tree only articulates later. Fuzzy/embedding merge
adjudication stays deferred (conservative exact/alias only).
The chat turn is now composed, not implemented, by chat-handler.ts:
- src/server/turn-service.ts: one named, error-contained seam per turn
responsibility — buildTeacherContext (W8 read channel), persistTurn
(canonical state write), spawnTurnJobs (async protocol kick-off),
foldTurnIntoGraph (session→graph consolidation; the extraction-pipeline
stage swaps this body behind the same seam). Each takes its deps
explicitly; failures log one [chat <id>] line and never touch the
response.
- chat-handler.ts wires: storage ports (stores), the job runner, the
teacher tools (ctx = chatId + injected ChatStore), and the services.
It no longer contains any logic beyond request validation.
Agent layer now receives dependencies instead of importing them — a new
lint zone enforces it (src/agent never imports src/server or src/store;
verified to fire both ways):
- runner.ts: createJobRunner({ chatStore, jobStore }) factory returning
the spawn hook + the three job runners; the model-override test seam
stays module-level. Bodies otherwise verbatim.
- plan tools: persist through the ctx-injected ChatStore
(TeacherToolContext = { chatId, chatStore }).
- teacher-agent's dependency-free default registry is now the true
client-side set: questionTools + jobTools (jobTools was ctx-parameter-
shaped but never used its ctx — now honestly context-free). Production
always passes createTeacherTools({ chatId, chatStore }); tests that
drive a bare mock model get the client-side set unchanged.
Zero behavior change: tsc clean, 190/190 tests, eslint clean, production
build clean. Tests inject the same fs ports the chat-handler does.
Per-entity semantic ports (src/core/ports.ts), one adapter family
(src/store/*, fs JSON/JSONL), exactly one composition point
(src/server/stores.ts). Dependency direction is now machine-checked:
adapters implement core interfaces; core never imports an adapter.
The inversion:
- core/graph.ts (emitChat/getGraph/graphSnapshot/foldStaleChats) is now
pure — it takes the storage ports as explicit parameters (GraphDeps).
No store imports; newGraphNodeId is local; node id format unchanged.
- core/graph-context.ts buildGraphContext() no longer defaults to the
live ledgers: the chat-handler hands in getGraph(graphStore) per turn.
- store adapters export exactly one object each implementing their port
(chatStore/graphStore/jobStore); bodies otherwise verbatim.
NodeMapping + SessionCheckpoint moved store/graph -> core/contracts
(they ARE contract shapes); CreateJobInit/JobPatch live in ports.
- titleFromPrompt moved store/chats -> core/contracts (pure helper,
planNodeStatus precedent). Store modules now contain persistence only.
- server/stores.ts is the composition root; server/{chats,graph,jobs}.ts
and chat-handler wire from it; agent (plan tools, sub-agent runner)
call the port objects. The shell surface (@/src/server exports) is
unchanged.
Lint law extended: the whole of src/core is now a purity zone (was a
file glob with a graph/graph-context exemption). Verified it fires on
core->store imports; tsc clean, 190/190 tests, eslint clean, prod build
clean (prerender 6/6). Tests pass deps explicitly — graph.test uses the
same fs-adapter pair stores.ts wires in production; graph-context.test
keeps its in-memory ledgers as a GraphStore implementation.
The shell now imports through exactly two barrels, enforced by
import/no-restricted-paths (npm run lint):
components/** -> "@/src/core" (pure core API, browser-safe)
app/** -> "@/src/core" + "@/src/server" (server entries)
Zone violations are lint errors with architecture-pointer messages; the
pure-core modules (contracts, question-core, plan-tree, phases, pending,
math-delims, ui-message) may never import agent/server/store.
Supporting moves (direction: IO layers -> core):
- core/index.ts: the core public API barrel
- core/ui-message.ts: moved from src/agent (it was shell-facing all along)
- quiz/ask input zod schemas moved agent/tools -> core/question-core
(the question contract, alongside the grading logic)
- ChatRecord/ChatSummary moved store/chats -> core/contracts (single schema)
- GraphSnapshot/NodeStateClass moved core/graph -> core/contracts (the
/api/graph payload IS a contract; the pure renderer needs only these)
- src/server/{chats,graph,jobs}.ts + index.ts: thin server entries for the
transport layer; GET /api/graph's fold side-effect now lives behind
graphView() instead of inline in the route
Gates: tsc clean, 190/190 tests, eslint clean (law verified to fire on
store/agent/subpath violations), production build clean.
(Repo repair en route: a git object (app/chat/[id] tree) was missing from
the object store — reconstructed byte-exactly via mktree from its blob;
the broken node_modules that stalled the build was cleanly reinstalled.)
- src/store/jobs.ts: per-job JSON store in data/jobs (create/get/update/list,
dedup by toolCallId)
- src/agent/tools/jobs.ts: research tool — client-side (no execute), turn ends
at the call; input per contracts ResearchToolInput
- src/agent/tools/web.ts: server-side web_search (Google CSE) + web_fetch
(Readability/Turndown/linkedom, Jina fallback) — errors return as strings,
never thrown into the agent loop. Deps: @mozilla/readability, linkedom,
turndown (+@types/turndown dev)
- src/agent/subagents/researcher.ts: isolated ToolLoopAgent (web tools only,
12-step cap), researcher prompt ported from pi
- src/agent/subagents/runner.ts: spawnPendingJobs hook + runResearchJob —
fire-and-forget, activity line per tool call, fulfills the part in the
LATEST chat record (output-available) before flipping job status; failure
still fulfills the part so the teacher learns the outcome
- src/server/chat-handler.ts: onFinish spawn hook after saveMessages
- app/api/jobs/route.ts: GET ?chatId= polling endpoint
- components/artifacts/job-card.tsx + registry entry: polling activity card
(2s) → syncFromServer on finish; research-brief card (markdown + sources)
- src/agent/prompts/20-jobs.md: research doctrine for the teacher
- tests/jobs.test.ts: store CRUD, spawn hook via scripted mock teacher,
runner completion/failure with fake model + stubbed fetch
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.
Root causes of the v1 browser bugs (all fixed + covered by deterministic tests):
- duplicated messages: per-socket snapshot + global broadcast marking raced;
replaced with a single append-only entry log (exactly-once per socket,
structurally) — covered by tests/server.test.ts
- delayed/missing echo of own messages: optimistic append with sending/failed
status, reconciled by text when the real entry arrives
- no thinking shown: thinking deltas streamed live (kind: thinking) and
persisted in assistant entries so they survive reloads
- ask answers graded as wrong: AnsweredCard no longer applies quiz grading to
ask answers (no ✓/✗, no verdict)
- broken option selection: native radio/checkbox inputs fighting React state
replaced with button-based options (single source of truth, one-click select)
- no URLs: History API routing — / home, /s/<file> per session (deep links,
refresh, back button); session view resumes its file on mount
- lost connection = dead UI: exponential-backoff reconnect with full resync
- stick-to-bottom transcript with jump-to-latest pill
Server: startServer() with injectable runtime factory (scripted model in
tests); createSession returns file for routing; scripted model gained thinking
turns. 51 deterministic tests green.
Amos