---
model: gpt-5.6-sol
provider: openai
service: opencode
session: 24fb9765-a550-4570-8350-f0fc9b7e17db
timestamp: 2026-07-29T03:41:06Z
git_ref: 922a5df8
scope: code
substantive: true
raw_file: 20260729T034106Z_922a5df8_prompt_io.raw.md
---

## Prompt

Diagnose the live IB reverse-fill failure where
`reqHistoricalDataAsync()` raised API error 10314 because its end date,
time, or timezone was invalid.

## Response summary

Traced the failure to `Client.bars()`, where an unfinished EST conversion
left the original datetime for `ib_async` to serialize as
`YYYYMMDD HH:MM:SS UTC`. Converted aware boundaries explicitly to UTC and
passed IB's accepted `YYYYMMDD-HH:MM:SS` string while retaining a blank
latest-request boundary. Added exact request-argument regressions.

## Files changed

- `piker/brokers/ib/api.py` - explicit UTC-dash history boundary format
- `tests/test_ib_history.py` - IB request-format regressions
- `.claude/skills/run-tests/test-harness-reference.md`
  - deterministic IB history test mapping
- `ai/prompt-io/opencode/20260729T034106Z_922a5df8_prompt_io.raw.md`
  - unedited response record
- `ai/prompt-io/opencode/20260729T034106Z_922a5df8_prompt_io.md`
  - provenance metadata and response summary

## Human edits

None - generated changes have not been edited by the human.