- The three panel modes were three separate fixed-width asides, so a
mode switch jumped the whole transcript column width in one frame:
scrollbar flash, overshoot, re-correct. Now ONE aside animates its
width exactly like the left sidebar (reusing the sidebar-motion
hook, so it inherits the provider's mount-gated transition), with
a FIXED-width inner layer clipped by overflow-hidden — content
never reflows mid-transition.
- The chat header was auto-height: the sidebar toggle (a size-9 icon
button) renders only while the sidebar is closed, so opening it
collapsed the row and slid the title + phase chip up. The header is
now a constant h-10.
- Chat page: the tree panel is now a full-height sibling of the whole
transcript column (header + scroller), exactly like the left sidebar —
the session header (name + phase chip) spans from the left sidebar's
edge to the panel's edge instead of riding over the panel.
- Plan graph: the zoom controls sit inside the pan surface, so their
pointerdown started a capture drag and the click never reached the
button (felt dead). startDrag now ignores presses on buttons.
- Fully zoomed out IS the fit view: zooming to the floor snaps to the
centered fit (pure zoomedGraphView), pan is locked there (no drag
begins, cursor-default instead of grab), and sitting at the floor
re-arms auto-fit so later tree edits keep the graph fitting.
- Fit padding 48px → 16px: the default view fits more graph.
- components/phase-divider.tsx: PhaseChip (header, next to the session
title: phase-colored dot + Probing/Planning/Teaching) and PhaseDivider
(the transcript boundary: color-coded dotted rules + a small chip —
'Plan · N nodes' at the plan seam, 'Teaching' at the teach seam; probe
never renders, phases only advance). planNodeCount reads the seam
message's first plan tree.
- chat.tsx: dividers render at MESSAGE boundaries (phaseTimeline, one
linear fold) — the seam is the transition to the message's phase, so
the seam message's prose sits below its divider. requiresReveal now
uses phaseAt3 teach (an occupied node), so probe- AND plan-phase
questions auto-open.
- Retired the part-level plan-divider (artifact registry): the boundary
is message-level, not part-level. Its tests replaced by
render-phase-divider tests; core/phases gains tested phaseTimeline.
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.
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.)
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).
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.
- Chat now remounts per session (key={chat.id}): fresh StickToBottom,
fresh DockOverlay (no cross-session morph from the previous shell
height), fresh useChat.
- Conversation initial="instant" (was "smooth"): the mount scroll to
bottom is a jump, not a slide.
- DockOverlay skips the pending-question scroll/expand effect for the
session's INITIAL pending question (dock starts expanded; the initial
scroll positions us) — previously it fired a second smooth
scrollToBottom right after the library's initial scroll (the visible
'pause, then the quiz pops and pushes everything up').
- The dock-variant fade/rise no longer plays for the session's opening
variant; reserved for mid-session transitions.
Verified live: client-side switch settles at d=1px from the bottom within
one frame of content swap, dock open from the first frame, both
directions (quiz session, plain session).
- Oscillation fix: collapsing the dock frees ~Δpx of flow height; within
Δ of the bottom the browser clamps scrollTop to the new max, landing
the learner AT the bottom, which re-expanded the dock → loop. Now a
hysteresis state machine on the scroller's scroll events: collapse only
when distance-from-bottom > Δ+64 (strictly clamp-proof), expand only
within 16px of the bottom. ~370px dead band; exactly one transition per
direction verified live. Heights measured live per question.
- Reaching the bottom re-expands the dock AND scrolls to reveal it fully
(previously it grew over the content and left you short of the bottom).
- Streaming follow fixed: ConversationContent had h-full, so the observed
content box never grew and use-stick-to-bottom's ResizeObserver never
fired — no auto-scroll during streaming. min-h-full restores growth.
Verified: distance-from-bottom ≤70px transient during a 25s stream,
settles at 1px.
- Animation: the blob's shell morphs height (WAAPI, 180ms) on every
variant change — chat ↔ question ↔ collapsed bar — plus a quick
fade/rise (160ms) on the swapped content. Gotcha pinned in code: never
measure the shell while a morph is in flight (getBoundingClientRect
reads the ANIMATED value and corrupts the next morph's start height);
cancel running morphs before measuring, refresh settled height only
when no morph is running.
- Gradient-over-scrollbar fixed structurally: the dock is no longer an
absolute overlay on the conversation root — it's sticky bottom-0 INSIDE
the scroller (in flow). The transcript scrolls fully clear of the dock,
the fade never touches the scrollbar lane, and the pb-hack clearances
are gone.
- New question while at the bottom scrolls to reveal the dock; scrolled
up → collapsed bar, no yank.
- Thin dark native scrollbar app-wide (8px webkit + scrollbar-width:thin,
dark thumb, transparent track). Note: use-stick-to-bottom sets
scrollbar-gutter: stable both-edges on its scroller — the lane is
outside the content flow by design.
- 'Writing a question…' transcript shimmer while a tool call streams its
input (same slot as 'Thinking…'). Protocol pinned by a test asserting
tool-input-start precedes tool-input-available; scripted mock now
streams tool input as deltas like real providers do. (OpenRouter/
Anthropic often delivers the whole input in ONE delta — then the dock
appears instantly and no indicator is needed or shown.)
Verified live: grow 54→349px and shrink 349→54px fire with correct
from/to; collapse/expand intact; gradient stops before the gutter;
Thinking… observed in-page; 58/58 tests.
- A pending quiz/ask now REPLACES the chat composer: one persistent
rounded-2xl shell in the transcript overlay swaps contents (composer ↔
question ↔ collapsed bar), never remounting — the structure a future
grow-morph animation needs.
- Unified bottom row inside the question: the note field (select modes),
the answer field (text-mode asks), or the Other text — one field, one
'Submit answer' button, Enter submits.
- Collapse on scroll: uses useStickToBottomContext — scroll up and the
dock folds to a slim bar (kind chip + LaTeX-flattened question teaser +
'tap to answer'); click scrolls to bottom and re-expands. The expanded
form stays mounted-hidden so a half-made selection survives.
- Pending/streaming tool parts no longer render inline; answered parts
land in the transcript as graded cards on submit. Question generation
shows a shimmer in the shell.
- Composer back to pure chat (no mode machinery); quiz-card.tsx and the
pendingText/registerSubmit bridge deleted; render tests re-pointed at
the dock (wrapped in StickToBottom).
Verified live: docked quiz submit (note+selection), ask-text Enter
submit, collapse/expand with selection survival, bar teaser text.
Sidebar (replaces the modal drawer):
- Inline, toggleable, no backdrop/focus theft — can stay open while working
- Open state persists across pages (provider in root layout) and reloads
(localStorage; starts closed server-side to avoid hydration mismatch,
stored value applied post-mount; default open on first run)
- Hamburger in page headers only when closed; close button in sidebar header
Floating composer blob (per reference screenshot):
- Floats over the transcript (absolute overlay), persists at bottom while
scrolling, content fades behind it (gradient mask); pb-44 scroll clearance
- Concentric corner radii: blob rounded-2xl(16px) − p-1.5(6px) = send
rounded-[10px] = 25% of the 40px button; CornerDownLeft icon per reference
- Stop moved from header into the blob (busy → square icon)
- prompt-input.tsx + 7 orphan ui files pruned (attachments/command palette
unused); hand-rolled Composer is ~100 lines and render-tested
Pending-question morph (one text field on screen, never two):
- Quiz/ask-select pending → blob becomes the note field (send hidden, hint
line above); card's internal note input removed; Submit consumes it
- Ask free-text pending → blob becomes the answer field; its send submits
via the card's registered submit api (ref bridge); Enter works
- Chat owns the single text state; card clears it on submit
- canSend for answer mode mirrors the card predicate directly — reading the
ref during render lagged one commit (found in browser testing)
Widths: one shared column (max-w-3xl + px-4) for transcript, cards, and
composer — all three measured pixel-identical (left 416, width 736).
Assistant Message max-w-full/MessageContent w-full (was max-w-[95%]/w-fit —
the 'cards are a bit shorter' bug).
User messages render plain text again — no math pipeline on learner-authored
text (currency hazard accepted for the model only, guarded by the prompt).
Tests: 58 pass (5 new composer pins; card tests updated to controlled
props). Verified live: note flow, answer flow, sidebar persistence, float,
fade, zero console errors — plus the live model spontaneously honoring the
$ currency escape contract in a continuation.
Layout:
- Home = knowledge-graph placeholder (main view) with new-session input
docked below; session list moved out of home into a hamburger drawer
- SessionDrawer: slide-over session navigation (backdrop/ESC close, active
highlight, fetches /api/chats on open) on both home and chat headers
- Chat header loses the back button — the drawer is the navigation
Math (inline $ was silently not rendering):
- @streamdown/math defaults singleDollarTextMath:false — now
createMathPlugin({ singleDollarTextMath: true }) in message + reasoning
- katex.min.css imported in layout (streamdown does not inject plugin
styles; display math only looked right via browser MathML fallback)
- QuizCard/AnsweredCard route question/options/explanation through
MessageResponse; user chat bubbles render markdown+math too
- Currency hazard: micromark-extension-math@3.1 lacks pandoc's
closing-digit rule, so bare '$5 and $10' parses as math — defense is at
the source: system prompt now instructs escaped \$5 / 'USD' for money
Hydration fix (React #418):
- QuizCard shuffled options with Math.random() — server/client orders
diverged. shuffleOptions now takes an injectable RNG; QuizCard passes
seededRandom(toolCallId) (mulberry32/FNV-1a in question-core). Same
question → same stable order across reloads; still varies per question.
Tests: 53 pass (5 new math-rendering pins incl. fenced-vs-one-line $$
behavior and the escaped-currency contract). tsc + next build clean.
Verified live in browser: inline/display math in text + cards, drawer
open/navigate/active-highlight/ESC, no console errors, no font 404s.
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.
amosblomqvist