docs(02-02-FIX): complete UAT-001 fix plan

UAT-001 resolved - fal.ai API 400 error fixed
- Removed buildCategoryFilter() causing multiple category params
- Models now filtered client-side via isRelevantModel()

SUMMARY: .planning/phases/02-model-discovery/02-02-FIX-SUMMARY.md

.planning/phases/02-model-discovery/02-02-FIX-SUMMARY.md

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+---
+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*

.planning/phases/02-model-discovery/02-02-FIX.md

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+---
+phase: 02-model-discovery
+plan: 02-FIX
+type: fix
+---
+
+<objective>
+Fix 1 UAT issue from plan 02-02.
+
+Source: 02-02-ISSUES.md
+Priority: 0 critical, 1 major, 0 minor
+</objective>
+
+<execution_context>
+@~/.claude/get-shit-done/workflows/execute-phase.md
+@~/.claude/get-shit-done/templates/summary.md
+</execution_context>
+
+<context>
+@.planning/STATE.md
+@.planning/ROADMAP.md
+
+**Issues being fixed:**
+@.planning/phases/02-model-discovery/02-02-ISSUES.md
+
+**Original plan for reference:**
+@.planning/phases/02-model-discovery/02-02-PLAN.md
+</context>
+
+<tasks>
+
+<task type="auto">
+  <name>Task 1: Fix UAT-001 - Multiple category parameters causing 400 error</name>
+  <files>src/app/api/providers/fal/models/route.ts, src/lib/providers/fal.ts</files>
+  <action>
+Fix the fal.ai API route to handle multiple categories correctly.
+
+**Root cause:** The `buildCategoryFilter()` function creates `category=text-to-image&category=image-to-image&...` but fal.ai API only accepts a single category parameter.
+
+**Fix approach:** Fetch all models without category filter and filter client-side.
+
+1. In route.ts:
+   - Remove `buildCategoryFilter()` function entirely
+   - Remove category params from URL construction (line 130)
+   - Keep only `status=active` in base URL
+   - Rely on existing `isRelevantModel()` filter (line 172) to filter results
+
+2. In fal.ts (provider):
+   - Apply same fix to `listModels()` and `searchModels()` functions
+   - Remove any category URL params, filter results after fetch
+
+**Why this approach:**
+- Simpler than making 4 parallel API calls per category
+- fal.ai returns manageable number of models
+- Filtering is already implemented via `isRelevantModel()`
+- No additional latency from multiple requests
+  </action>
+  <verify>
+curl -X GET "http://localhost:3000/api/providers/fal/models" returns JSON with success:true and models array
+  </verify>
+  <done>
+- API route returns 200 with models array
+- Models are filtered to only image/video categories
+- No 400 errors from fal.ai
+  </done>
+</task>
+
+</tasks>
+
+<verification>
+Before declaring plan complete:
+- [ ] `curl http://localhost:3000/api/providers/fal/models` returns success:true
+- [ ] Response contains models with capabilities: text-to-image, image-to-image, text-to-video, image-to-video
+- [ ] No models with other categories (audio, 3D, etc.) in response
+- [ ] TypeScript compiles: `npx tsc --noEmit`
+- [ ] Build succeeds: `npm run build`
+</verification>
+
+<success_criteria>
+- UAT-001 resolved - API route returns models without 400 error
+- Models still filtered to relevant image/video categories
+- No regression in other functionality
+</success_criteria>
+
+<output>
+After completion, create `.planning/phases/02-model-discovery/02-02-FIX-SUMMARY.md`
+</output>

.planning/phases/02-model-discovery/02-02-ISSUES.md

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+# UAT Issues: Phase 02 Plan 02
+
+**Tested:** 2026-01-09
+**Source:** .planning/phases/02-model-discovery/02-02-SUMMARY.md
+**Tester:** User via /gsd:verify-work
+
+## Open Issues
+
+[None]
+
+## Resolved Issues
+
+### UAT-001: fal.ai API route returns 400 error due to multiple category parameters
+
+**Discovered:** 2026-01-09
+**Phase/Plan:** 02-02
+**Severity:** Major
+**Resolved:** 2026-01-09 - Fixed in 02-02-FIX.md
+**Commit:** 2fe312d
+
+**Description:** The fal.ai models API route constructs a URL with multiple `category=` parameters (text-to-image, image-to-image, text-to-video, image-to-video), but fal.ai's API only accepts a single category parameter. This causes a 400 validation error.
+
+**Fix:** Removed `buildCategoryFilter()` function. Now fetches all active models without category filter and relies on existing `isRelevantModel()` function to filter results client-side.
+
+---
+
+*Phase: 02-model-discovery*
+*Plan: 02*
+*Tested: 2026-01-09*