The pi-style ack protocol (previous commit) left the client describing the
old world: artifact cards read the ack string as a result ("could not be
displayed"), the only job poller rendered on input-available parts that no
longer exist (so wake turns landed invisibly until re-navigation), steers
rendered as learner bubbles with no SVG anywhere, and server-persisted
assistant messages carried empty SDK ids (duplicate React keys).
- persistTurn (turn-service): fill empty message ids at the canonical write
— server-only messages (last turn's, wake turns') now key uniquely;
client-authored ids untouched.
- chat.tsx: ONE central /api/jobs poll (fast while jobs run, slow discovery
cadence, off for job-less sessions) drives every job surface, re-syncs
once when a job settles (the record already holds the steer + wake
response at flip time), and adopts server-side wake turns via the same
turnInFlight machinery as returning mid-turn. Steers branch to the
artifact card — never a bubble. Composer no longer gates on jobs.
- /api/jobs now reports turnInFlight alongside the job list.
- dispatch-card: the tool-call box — live activity by toolCallId while
running, quiet "delivered"/"failed" one-liner after; the ack is visible
observability, the artifact lives in the steer.
- steer-card: renders the delivered artifact by kind (research brief /
sanitized SVG / sandboxed demo iframe) from the data-subagent-artifact
part; result renderers extracted and exported from the artifact cards.
- sub-agents-panel: right-sidebar section above the plan tree listing
running sub-agents (kind, elapsed, live activity) — vanishes when idle.
- tests: dispatch/steer/panel render tests re-target the new protocol;
persistTurn id-hygiene suite. 229/229 green, build green.
Out-of-lane touches for master review: chat.tsx + components/** (cleared
this wave), app/api/jobs/route.ts, src/server/turn-service.ts, contracts
protocol doc §2. Live-verified on :3003 (full loop, SSR DOM checked).
The job tools (research/demo/visual) switch from client-side turn-breaking
calls to pi's model: execute resolves IMMEDIATELY with a fire-and-forget
ack, the teacher's turn continues, and the result arrives later as an
injected user-role steer message that wakes the teacher in a new
server-side turn.
- contracts.ts: THE ASYNC PROTOCOL rewritten (ack now, steer later); steer
types (SubagentSteerMessage, metadata.subagentResult + data-subagent-
artifact part), pure buildSubagentSteer/steerDelivered/isSubagentFailure
- tools/jobs.ts: jobTools(ctx) factory — server-side execute creates the
job (deduped by toolCallId), fires spawn with the dispatch-time input
(the part isn't persisted yet at execute — a transcript scan would race)
- runner.ts: runJob(jobId, input?) builds the steer and hands it to the
injected deliver seam; pipeline owns the done/error flip (a polling
client re-syncs once, at the end); failures still steer
- server/jobs.ts (new pipeline): per-chat serialized queues on globalThis,
idle gates (turn liveness + pending question, 1.5s grace), 409 retry
with backoff, idempotent per jobId, stale-job recovery sweep (re-deliver
or re-spawn); wake turns run through the same handleChatRequest
composition via setTurnRunner injection
- chat-handler.ts: wires runner+deliver+tools ctx; drops spawnTurnJobs
from onFinish; teacher default registry = question tools only
- plan.ts: PlanToolContext split out (plan tools need no job wiring)
- visual-maker: edit_svg added (pi parity — exact-match single
replacement, fuzzy context on a miss); researcher: pi's kept/dropped
source accounting restored
- prompts 20-jobs/40-demos: async discipline rewritten (announce and keep
teaching, no waiting/polling/fabricating, parallel dispatch, teach with
the artifact when it arrives)
- tests: jobs.test.ts rewritten (dispatch ack mid-turn, runner steers,
wake pipeline: deferral/409/idempotency/failure), demos.test.tsx runner
tests ported to runJob + fake deliver; 222 green
FLAGGED surgical touches outside the stream's owned files, for master
review at merge: src/core/contracts.ts (protocol doc + steer types),
src/core/ui-message.ts (job tool + data-part types), src/server/
chat-handler.ts (wiring), src/server/turn-service.ts (spawnTurnJobs
retirement), src/agent/teacher-agent.ts (default tools), src/agent/tools/
plan.ts (context type split).
Verified live on PORT=3003 with real models: teacher dispatched research
mid-turn, researcher ran real searches/fetches, steer injected on quiz
answer, wake turn wove the brief in citing its sources, job flipped done;
a client/wake race correctly 409'd.
Schema: GraphNode + ExtractedProposition carry 'name' — a short 2-6 word
header, the rendering handle. Node theory made explicit: a node is an
objective world-facing fact; the learner's relationship to it lives
entirely in the event ledger (state labels are derived, never stored).
Extractor + auditor instructions enforce it — misconceptions state the
wrong idea itself as a claim, never 'the learner believes Y'. Legacy
ledger lines without a name derive one from the statement on read.
graph-view: labels use the name; the detail panel shows name as header
and statement as body.
Compared the port against the original pi setup
(vault/π/learn/.pi: quiz.ts, ask-user-question.ts, teach SKILL.md) —
the pi version never produced invalid correctAnswer values. Root cause
of the port's validation failures: the pi options schema's 'Give each
option a stable value; you reference the correct one by that value in
correctAnswer' sentence was dropped in the port. Without it the model
omits values and must copy a long natural-language label verbatim into
correctAnswer — and instead slugifies it ('cultural-diagnosis' for
'A cultural diagnosis') every turn.
Now matched to pi:
- quiz schema: pi's field order (question, details, options,
multiSelect, correctAnswer, explanation) and descriptions — options
carry the stable-value instruction, correctAnswer is phrased as a
value reference ('the value field of the option you intend'), not a
copy-exact-or-fail threat. nodeId (lh-only, graph) stays.
- ask schema: dropped the redundant 'mode' param (pi has none; the dock
already infers from options presence), pi's descriptions.
- quiz tool description: pi's full text (ask contrast, note field,
dontKnow semantics) minus terminal-only details, plus lh's turn
protocol sentence.
- system-prompt: fixed the stale 'exactly two tools' line (plan/research/
demo/visual tools have their own sections).
Not matched, deliberately: tool results stay JSON (pi sends curated
text; formatAnswerMessage exists if we want it later), shuffle param
(lh always shuffles seeded), pi's ask '(Recommended)' label hint.
In Next dev (Turbopack), each route compiles as its own entry — a
module-level Map in turn-liveness.ts was a DIFFERENT instance in the page
render, GET /api/chats/[id], and POST /api/chat. The chat route held the
live turn (hence the 409), but the page render read an empty registry:
initiallyInFlight=false → mount continuation fired a send → 409 → the
'Something went wrong' banner on returning mid-turn. The registry now
lives on globalThis (the standard Next singleton channel) — one Map per
process regardless of module instances. Semantics unchanged (TTL leak
guard, begin/end round trip).
Browser-verified end-to-end (headless tester): answer quiz → navigate
away → return mid-turn → graded card (no re-prompt), 'Thinking…' shimmer,
composer gated, no error banner; teacher response auto-delivered when the
background turn finished. Polling GET /api/chats/[id] observed working.
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.
MODELS in config.ts is now THE single tuning table: model id + OpenRouter
reasoning effort for teacher/researcher/demoBuilder/visualMaker/extractor/
auditor. .env.local is secrets-only (LH_* model vars removed; all sub-agents
previously had NO reasoning setting -> provider-default unbounded thinking,
the extraction token burn). One factory (src/agent/models.ts modelFor) wires
all six call sites; test injection unchanged. EXTRACTION.everyNQuizAnswers
moved to a config literal too. Plus the §5 one-line-per-seam logging in the
extraction pipeline: pipeline start, extractor/auditor start + per-step,
audit kept, merged — previously silent until completion, which made live
runs look like they never fired.
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.
- Commands: add npm run lint (with the import-law note)
- Architecture: one-sentence orientation before the mermaid; split the
turn composition (src/server: chat-handler) out of the teacher-agent
subgraph — the diagram now matches the layers
- Layout: add the server route entry points + the server barrel
- Header: quiz outcomes reach the graph through the extraction pipeline
Replaces the pre-pivot v0 scaffold doc (preserved in git history) with
the as-built spec: the five layers and their dependency directions, the
machine-enforced import law (four zones + the two documented-only
rules), ports/adapters and the two composition roots, the extraction
pipeline as sole graph writer (division of trust, merger invariants,
probe-attribution resolution, the v1 trigger seam), the pure read
channel, the turn seams, minimal observability, the testing strata, and
the deferred-with-links list. The doc states it describes the system,
not an intention — it changes with the commit that changes the system.
README reference updated (was: 'pre-pivot v0 scaffold — history only').
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.)
Delete src/extract/ (pi-session normalize/extract/merge stubs), src/ledger.ts,
src/schema.ts, src/derive.ts, src/queries/, src/cli.ts (npm run ingest/graph/
what-next), data/legacy-graph/, data/agent/ (pi agentDir vestige), and their
config.ts/package.json references.
The retroactive-bootstrap goal is dropped: the live chat store (AI SDK
UIMessages) is the only session format now, and the old pi JSONLs in
data/sessions/ stay on disk, inert. contracts.ts is the single schema.
The old README documented the pre-pivot pi/Fastify/Vite scaffold (npm run
teach, doctor scripts, Fastify+WS server, extensions/) — all removed in the
pivot to standalone Next.js + Vercel AI SDK. New README covers the current
commands, env vars, embedded architecture diagram, key mechanisms
(client-side question tools, plan tree, async sub-agent protocol, live
graph emission), the dormant legacy scaffold, testing, and lineage.
Also commits the pending next-env.d.ts regeneration.
Gate 1 found the teacher staying silent after a research brief landed.
The SDK only evaluates sendAutomaticallyWhen inside addToolOutput — an
external setMessages (our syncFromServer) updates the UI but never
triggers the continuation. Fix: syncFromServer checks
lastAssistantMessageIsCompleteWithToolCalls and calls sendMessage()
(itself a valid continuation trigger); plus a mount-continuation effect
for the reload case (job fulfilled while no client was open).
- src/core/math-delims.ts: pure preprocessing for the \(...\)/\[...\] math
contract — balanced delimiters rewrite to the two-dollar forms remark-math
parses ($ is never math). Skips code fences/spans, escaped delimiters, and
leaves unbalanced (mid-stream) delimiters untouched. Display math renders
as a block: mid-paragraph gets blank-line padding; indented (list items)
degrades to inline so list continuations don't half-parse.
- message.tsx: transform in the render path (children-memoized); math plugin
now singleDollarTextMath: false — the currency hazard dies structurally.
remark-breaks via the cjk remarkPluginsAfter slot (the bare remarkPlugins
prop would replace the [remark-gfm, codeMeta] defaults).
- mermaid: dark theme + sans font via Streamdown's mermaid prop; dark-styled
error fallback (components/mermaid-error.tsx) with error, source in
<details>, and retry.
- globals.css (appended): @source for streamdown dist — its internal UI
chrome (code blocks, mermaid containers, tables) was entirely unstyled
because Tailwind v4 never scans node_modules; --color-sidebar → card; wide
mermaid SVGs capped to the column; .katex-display scrolls.
- tests/render-markdown.test.tsx: 26 tests (transform unit + render). The
math describe block in render-cards.test.tsx is updated to the new
contract ($...$ now renders as literal text — pinned).
- 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
- src/core/plan-tree.ts: pure tree ops (createTree/addNode/updateNode/removeNode/
addEdge/removeEdge/setCurrent/markDone), DAG invariants (unique ids, existing
endpoints, no self-loops/duplicates/cycles), cascade remove, version bumps on
state changes only (true no-ops for idempotent setCurrent/markDone).
- src/agent/tools/plan.ts: plan_init (refuses re-init), plan_add_node (optional
parents → requires edges), plan_update_node, plan_remove_node, plan_add_edge,
plan_remove_edge, plan_set_current, plan_mark_done. Execute = getChat → op →
saveTree → PlanToolResult with the full updated tree; PlanTreeError and missing
chats become {ok:false, error, tree}.
- src/agent/prompts/10-plan-tree.md: tree-authoring doctrine (when: post-probe;
grain: one reasoning step per node; discipline: set_current on start,
mark_done on demonstrated mastery; freedom: mid-session restructure).
- tests/plan-tree.test.ts: every validation error path, version semantics,
cascade remove, no-mutation, tool round-trips against the real chat store.
- Every session starts with the learner's knowledge graph as base
context (precision probing); selection problem noted: pedagogical
relevance != semantic closeness (structural neighborhood, diagnostic
hotspots, frontier strip); strategies to tune on data.
- Sub-agent architecture: async background workers with live activity
indicators; demo-builder TESTS code headlessly; visual-maker verifies
by looking (port of vault svg-maker); mermaid needs no sub-agent;
researcher tool for fact verification (port of pi web-search/web-fetch
+ interactive-subagents researcher prompt).
- Not-a-chat presentation principle marked LOW PRIORITY per user.
Margin model flaws (user feedback): fragment placement needs unreliable
routing; scattering kills the receipt moment and chronology; session
value is in the moment, revision is rare, HTML export deprioritized.
Evolved model: one chronological spine; learner blocks are intact typed
'interjection' cards; teacher replies as woven Q&A interludes
(quote-then-answer); anchoring is a link overlay (backlinks), margins
demoted to a computed view. Chat-ness dies by type asymmetry, not
relocation.
Asymmetry of artifact: the teacher writes the document (whiteboard), the
learner writes in the margins (voice/floor). Bubbles die; the unit is the
block; chronology yields to tree structure; Q&A becomes document
furniture; the composer becomes a response field. Presentation-layer
change only — the interaction model stays conversational.
Captures 2026-08-22 decisions: hybrid live-emission + consolidation graph
construction (reversing the vault doc's teacher-untouched rule), one
substrate merged across sessions, structured plan-tree tools (mermaid
demoted to ad-hoc), probe/teach phase separation with collapsed teach
checks, right-panel tree view, LaTeX delimiter switch plan, and a
dependency-ordered roadmap.
Clicking the collapsed bar set expanded=true and started a smooth
scrollToBottom — but the scroll position was still legitimately inside
the collapse zone (that's why the bar was showing), so the hysteresis
listener re-collapsed the dock on the very next scroll event, then
re-opened it when the scroll arrived: open → snap shut → reopen.
The machine had no notion of intent. Now the bar click sets an
expandIntent flag that suppresses the collapse branch; it clears when
the scrollToBottom promise settles (completion or interruption) or after
a 2s safety net, so a user yanking the scroll away mid-reveal collapses
the dock again instead of wedging it open.
Verified live: click = exactly one transition (bar→open at ~26ms, stays
open, lands at d=1); collapse still healthy afterward; mid-reveal
interrupt re-collapses within ~300ms.
amosblomqvist