---
phase: 02-model-discovery
plan: 02-FIX
type: fix
subsystem: api
tags: [fal.ai, api, providers, models]

# Dependency graph
requires:
  - phase: 02-model-discovery
    provides: fal.ai provider and models API route
provides:
  - Working fal.ai models endpoint that returns 200 instead of 400
affects: [02-model-discovery, provider-testing]

# Tech tracking
tech-stack:
  added: []
  patterns: [client-side-filtering]

key-files:
  created: []
  modified:
    - src/app/api/providers/fal/models/route.ts
    - src/lib/providers/fal.ts

key-decisions:
  - "Fetch all active models without category filter, filter client-side"
  - "fal.ai API only accepts single category param - multiple params cause 400"

patterns-established:
  - "Post-fetch filtering: When API doesn't support multiple filter values, fetch broader and filter client-side"

issues-created: []

# Metrics
duration: 5min
completed: 2026-01-09
---

# Phase 02 Fix: fal.ai API 400 Error Summary

**Removed multiple category params from fal.ai API requests to fix 400 error - models now filtered client-side**

## Performance

- **Duration:** 5 min
- **Started:** 2026-01-09
- **Completed:** 2026-01-09
- **Tasks:** 1
- **Files modified:** 2

## Accomplishments
- Fixed UAT-001: fal.ai models endpoint now returns 200 with models array
- Removed buildCategoryFilter() function from both route.ts and fal.ts
- Models still correctly filtered to relevant categories (text-to-image, image-to-image, text-to-video, image-to-video)

## Task Commits

1. **Task 1: Fix UAT-001 - Multiple category parameters causing 400 error** - `2fe312d` (fix)

## Files Created/Modified
- `src/app/api/providers/fal/models/route.ts` - Removed buildCategoryFilter(), simplified URL to use only status=active
- `src/lib/providers/fal.ts` - Same fix applied to listModels() and searchModels() methods

## Decisions Made
- Fetch all active models without category filter, rely on existing isRelevantModel() function to filter results
- This approach is simpler than making 4 parallel API calls (one per category)
- fal.ai returns a manageable number of models, so client-side filtering is efficient

## Deviations from Plan
None - plan executed exactly as written

## Issues Encountered
None

## Next Phase Readiness
- fal.ai provider is now fully functional
- Ready to proceed with additional provider implementations or UI integration

---
*Phase: 02-model-discovery*
*Plan: 02-FIX*
*Completed: 2026-01-09*