Fix A2 of plans/2026-07-11-nomos-agent-code-review.md. chatWith replayed a
session's ENTIRE message history into the LLM's context on EVERY turn, no
windowing, no token budget — confirmed against a documented production case
(a single turn with 70 tool calls, messages up to 106KB). Every subsequent
turn of a long-running or heavily-autonomous task re-sent that ever-growing
history in full — a real cost/latency/eventual-context-limit risk for
exactly the tasks this system runs longest (many auto-continuation cycles).
Design call (flagged in the review as needing one before implementation):
a fixed-size window for LLM replay specifically, not the UI's own transcript
view. Simplest option that still keeps roughly the current task's working
context; a token-aware trim or LLM-summarize-on-drop are documented as
stretch options if 30 proves insufficient in practice.
- store.go: new getRecentMessages(ctx, sessionID, limit) — last `limit`
messages in chronological order, plus whether older ones were omitted.
getMessages (used by the UI's GET /sessions/{id}) is untouched and stays
unbounded — the operator should still see a task's full history regardless
of length; only what gets sent to the model is bounded.
- agent.go: chatWith uses getRecentMessages(sessionID, historyWindowSize=30)
instead of the unbounded getMessages. When truncated, injects a system
note telling the model explicitly that older turns exist but aren't shown,
so it checks upsert_knowledge/search_knowledge rather than assuming
something wasn't done just because it isn't visible.
New cmd/nomos/store_test.go: real Postgres integration tests (mirroring
internal/db/integration_test.go's throwaway-database pattern, guarded by
OIKOS_TEST_DATABASE_URL). TestGetRecentMessages_Truncation is the direct
proof for this fix (35 messages → 30 returned, correctly ordered,
truncated=true; 5 messages → all 5, truncated=false) — both cases run
against a fully-migrated database, not mocked. Also added
TestProposePlan_AppendVsReplace, closing part of the review's test-coverage
finding (E) by permanently regression-testing the earlier append-vs-replace
plan fix (commit 5384499), which had only been verified manually until now.
Verified live: inflated a real session to 42 persisted messages via direct
SQL, then continued it with a real chat call — the turn proceeded normally
(multiple real tool-call iterations, no crash, no context-length error);
nomos stayed healthy throughout. A3's incremental persistence separately
confirmed to have caught the 7 real tool calls made before the client
connection was cut, cleanly closing out both fixes' interaction.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
dtoro
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