---
phase: 07-config-history-ui
plan: 01
subsystem: ui
tags: [react, tanstack-query, timeline, config-history]

requires:
  - phase: 06-history-api
    provides: GET /api/tenants/{tid}/devices/{did}/config-history endpoint
provides:
  - ConfigHistorySection component with timeline rendering
  - configHistoryApi.list() API client function
  - Configuration history visible on device detail overview tab
affects: [07-config-history-ui]

tech-stack:
  added: []
  patterns: [timeline component pattern matching BackupTimeline.tsx]

key-files:
  created:
    - frontend/src/components/config/ConfigHistorySection.tsx
  modified:
    - frontend/src/lib/api.ts
    - frontend/src/routes/_authenticated/tenants/$tenantId/devices/$deviceId.tsx

key-decisions:
  - "Reimplemented formatRelativeTime locally rather than extracting shared util (matches BackupTimeline pattern)"
  - "Poll interval 60s via refetchInterval for near-real-time change visibility"

patterns-established:
  - "Config history timeline: vertical dot timeline with component badge, summary, line delta, relative time"

requirements-completed: [UI-01, UI-02]

duration: 3min
completed: 2026-03-13
---

# Phase 7 Plan 1: Config History UI Summary

**ConfigHistorySection timeline component on device detail page, fetching change entries via TanStack Query with 60s polling**

## Performance

- **Duration:** 3 min
- **Started:** 2026-03-13T04:11:08Z
- **Completed:** 2026-03-13T04:14:00Z
- **Tasks:** 2
- **Files modified:** 3

## Accomplishments
- Added configHistoryApi.list() and ConfigChangeEntry interface to api.ts
- Created ConfigHistorySection with vertical timeline, loading skeleton, and empty state
- Wired component into device detail overview tab below Interface Utilization

## Task Commits

Each task was committed atomically:

1. **Task 1: API client and ConfigHistorySection component** - `6bd2451` (feat)
2. **Task 2: Wire ConfigHistorySection into device detail page** - `36861ff` (feat)

## Files Created/Modified
- `frontend/src/lib/api.ts` - Added ConfigChangeEntry interface and configHistoryApi.list()
- `frontend/src/components/config/ConfigHistorySection.tsx` - Timeline component with loading/empty/data states
- `frontend/src/routes/_authenticated/tenants/$tenantId/devices/$deviceId.tsx` - Import and render ConfigHistorySection

## Decisions Made
- Reimplemented formatRelativeTime locally (same pattern as BackupTimeline.tsx) rather than extracting to shared util -- keeps components self-contained
- Used 60s refetchInterval for polling new config changes

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered
None

## User Setup Required
None - no external service configuration required.

## Next Phase Readiness
- Config history timeline renders on device overview tab
- Ready for any future detail/drill-down views on individual changes

---
*Phase: 07-config-history-ui*
*Completed: 2026-03-13*