Root cause of the live-test bugs (2026-09-19): pi passes every run's
AbortSignal to tool execute, but toPiTool dropped it — agent.abort()
only landed at the next step boundary, so a long local grep held its
turn hostage until the dev server's memory restart killed the run
mid-tool, freezing the record at its write-ahead state (the 'went
back in time' rollback).
- lh-tool: execute ctx gains signal (parent + timeout combined); every
call races a 30s system-level timeout with a 250ms cooperative grace —
abort kills a stuck tool but lets a poll-the-signal tool deliver its
partial results. Pre-aborted signals never fire listeners: checked
upfront. toolTimeoutMs is the test seam (pdfModelOverride idiom).
- fs-shared: walkFiles returns {timedOut, aborted} instead of throwing —
abort yields partial results.
- grep: the scan phase was unbounded (the walk's 10s deadline only
bounded collection) — same budget now checked per file; find/grep
check the signal and return partials with a notice.
- pending/chat: streamingToolActivity names the ACTUAL running tool —
a part sits input-streaming through its whole execution, so the old
shimmer called minutes-long greps 'Writing a question…'.
Tests: toPiTool guard (forward, abort, timeout, grace, question
bypass, ToolInputError passthrough), walk mid-abort, find/grep
pre-abort + mid-run abort, activity labels. Gates: 617/617.
User pivot (2026-09-19): no attachments UI at all. Pasting paths is native
for technical users and alien for everyone else - so the agent gets the
tools to find what the learner merely NAMES. The learner communicates in
messages; the agent locates and reads. Zero cross-stream seams: paths
already live in tool parts, so the sources "list" is the transcript.
- ls/find/grep: pi-verbatim schemas, descriptions, and output formats
(fd's glob semantics, rg's path:line: match format, pi's truncation
notices), ported to pure Node - no binaries, no shell-out, read-only by
construction. Deltas from pi: home-anchored resolution (the harness has
no cwd), .gitignore replaced by hard noise exclusions
(node_modules/.git/Library/.Trash), 10s walk timeout with partial results.
- read: description swapped to pi-verbatim (doctrine moved to the prompt);
relative paths now resolve against the learner's home like the rest.
- prompts/shared/05-learner-files.md: one minimal doctrine fragment
composed into BOTH agents (composeInstructions grew a shared/ dir,
before the agent's own fragments). teacher/30-jobs.md keeps only the
pdf-dispatch addendum.
- ToolCallCard: the generic quiet tool-call card the user specced -
collapsed one-liner (tool name + headline argument), expandable to full
input/output, errors red, image payloads never render. Registered for
read/ls/find/grep.
- ui-message.ts: TeacherUITools entries for the four tools (mechanical).
- tests: fs-tools suite (glob semantics, pi formats, exclusions, limits),
registry/card renders, shared-fragment composition pins, tool-registry
key updates, read re-anchor.
amosblomqvist