---
phase: 02-legacy-pruning
plan: 02
subsystem: config
tags: [pydantic, sidecar, config-cleanup]

# Dependency graph
requires: []
provides:
  - "Clean SidecarConfig without dead gap_fill_on_startup field"
  - "CLI script without --no-gap-fill flag"
affects: []

# Tech tracking
tech-stack:
  added: []
  patterns: []

key-files:
  created: []
  modified:
    - python/opendeviationbar/config/sidecar.py
    - python/opendeviationbar/sidecar.pyi
    - scripts/streaming_sidecar.py
    - tests/test_sidecar.py
    - tests/test_sidecar_watchdog.py

key-decisions:
  - "No replacement field needed -- gap_fill_on_startup was dead code controlling removed startup gap-fill behavior"

patterns-established: []

requirements-completed: [PRUNE-04]

# Metrics
duration: 3min
completed: 2026-03-20
---

# Phase 02 Plan 02: Remove gap_fill_on_startup Config Summary

**Removed dead gap_fill_on_startup field from SidecarConfig, type stubs, CLI --no-gap-fill flag, and 9 test constructions**

## Performance

- **Duration:** 3 min
- **Started:** 2026-03-20T19:54:18Z
- **Completed:** 2026-03-20T20:17:41Z
- **Tasks:** 2
- **Files modified:** 5

## Accomplishments

- Removed gap_fill_on_startup field definition from SidecarConfig (config/sidecar.py)
- Removed type stub and CLI --no-gap-fill argument
- Cleaned 9 SidecarConfig constructions in watchdog tests and 1 docstring in sidecar tests
- Verified zero remaining references across entire Python/script codebase

## Task Commits

Each task was committed atomically:

1. **Task 1: Remove gap_fill_on_startup from config, stubs, and CLI** - `12e9074` (refactor)
2. **Task 2: Remove gap_fill_on_startup from all test files** - `8b497fa` (refactor)

## Files Created/Modified

- `python/opendeviationbar/config/sidecar.py` - Removed gap_fill_on_startup field and AliasChoices
- `python/opendeviationbar/sidecar.pyi` - Removed gap_fill_on_startup type stub line
- `scripts/streaming_sidecar.py` - Removed --no-gap-fill arg, docstring example, and config construction reference
- `tests/test_sidecar.py` - Updated docstring removing gap_fill_on_startup reference
- `tests/test_sidecar_watchdog.py` - Removed gap_fill_on_startup=False from 9 SidecarConfig constructions

## Decisions Made

None - followed plan as specified. The gap_fill_on_startup field was purely dead code with no replacement needed.

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered

None.

## User Setup Required

None - no external service configuration required.

## Next Phase Readiness

- PRUNE-04 complete: gap_fill_on_startup fully removed from codebase
- All legacy pruning for Phase 02 is now complete

---

_Phase: 02-legacy-pruning_
_Completed: 2026-03-20_
