---
model: openai/gpt-5.6-sol
service: opencode
session: 253ade33-07ba-45b5-8839-be35d17ec164
timestamp: 2026-07-29T20:40:46Z
git_ref: ad6c560f
scope: code
substantive: true
raw_file: 20260729T204046Z_ad6c560f_prompt_io.raw.md
---

## Prompt

The user reported that the QQQ 1-second chart still contained a gap after
the `ldshm` fix, asked the agent to inspect it, and authorized continued
implementation after a short pause and shutdown of the live workspace.

## Response summary

Diagnosed a 653-row active RT SHM null reservation caused by inclusive IB
reverse-query overlaps and startup repair orchestration. Prevented extra
physical SHM overlap rows, serialized and bounded IB history recovery,
made blank/error responses terminate, and constrained synthetic repair to
valid interior timestamp boundaries. Added deterministic concurrency and
data-layout regressions.

## Files changed

- `piker/brokers/ib/feed.py` - bound and serialize IB history reset/retry behavior.
- `piker/tsp/_history.py` - prevent SHM overlap skew and safely finalize null repair.
- `tests/test_ib_history.py` - cover blank, cancellation, reset, and pacing interleavings.
- `tests/test_history_backfill.py` - cover overlap and null-repair invariants.
- `.claude/skills/run-tests/test-harness-reference.md` - register deterministic coverage.

## Human edits

None - generated output remains uncommitted.