Diagnosis (2026-09-11 user testing, minimal-effort GLM): sessions stuck on
'plan' forever. Two causes: (1) the three-phase view read the stored tree's
currentNodeId, which nothing ever writes post author-once (2026-09-03) — a
structural dead seam; (2) the teacher stochastically left quiz.nodeId
untagged, and done-by-quiz-result semantics would have falsely completed
nodes anyway.
The redesign (docs/probe-teach-split.md) abolishes derived occupancy in
favor of explicit events:
- Two agents over one transcript: createProberAgent (quiz without a
nodeId field, ask, probe_done) and createTeacherAgent (full toolset,
plan_init onward). The chat-handler construction branch keys on a
probe_done part in the transcript. MODELS.prober added.
- probe_done: server-side seam tool — carries the learner assessment
(strands + free-form edge read), refuses while a question is open or
the probe is already concluded, and queues a handoff steer through the
generalized wake pipeline (steers now dedupe by id, not jobId; job
finalization only for job steers). The teacher auto-wakes and authors
the plan; the learner sees the assessment via the probe-done card.
- phases: probe ends at a concluded probe_done, plan ends at a
successful plan_init — strictly sequential, no skipping, no legacy
compatibility (data wiped at the pivot per doctrine).
- Plan map = position, not completion: derivePlanStatuses reads only
tagged quiz CALLS (state/outcome feed nothing); current = latest
tagged node with consecutive duplicates collapsed, visited = earlier
distinct stays (a revisit stays in both — current wins at render).
PlanTree is structure-only; currentNodeId/doneNodeIds and the dead
mutation helpers are gone. No fallback current.
- Prompts split per agent (prompts/prober/, prompts/teacher/ over the
trimmed shared base); graph-context injection removed entirely
(shelved, docs/probe-teach-split.md §5); knowledge-graph context no
longer reaches either agent.
- Plan blocks are full-only snapshots at plan_init (neighborhood
machinery retired; the persistent DAG window is the future UI wave);
usage capture unchanged.
Gates: tsc clean, 294/294 tests (phases/plan-tree/plan-blocks/question-
tools rewritten to the new semantics; probe-done + handoff-wake tests
added), lint, build. Live GLM smoke PASS: prober concluded with an honest
assessment, teacher auto-woke, authored a 10-node plan with the block
attached, then tagged checks on slope-instinct → secant derived current/
visited exactly as designed; grading honest both ways (driver off-by-one
proved a wrong answer grades false).
- 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.
amosblomqvist