docs(35-03): complete client-side wiring plan

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.planning/STATE.md

@@ -10,18 +10,18 @@ See: .planning/PROJECT.md (updated 2026-01-09)
 ## Current Position
 
 Phase: 35 of 35 (Large Workflow Handling)
-Plan: 1 of 3 in current phase
+Plan: 3 of 3 in current phase
 Status: Complete
-Last activity: 2026-01-31 - Completed plan 01 (Binary Stripping and Rich Workflow Context)
+Last activity: 2026-01-31 - Completed plan 03 (Client-side wiring and selection chip)
 
-Progress: ░░░░░░░░░░ 6%
+Progress: ██████████ 100%
 
 ## Performance Metrics
 
 **Velocity:**
-- Total plans completed: 35
-- Average duration: 7 min
-- Total execution time: 4.0 hours
+- Total plans completed: 37
+- Average duration: 6.9 min
+- Total execution time: 4.25 hours
 
 **By Phase:**
 
@@ -56,11 +56,11 @@ Progress: ░░░░░░░░░░ 6%
 | 32. Chat UI Foundation | 2/2 | 9 min | 4.5 min |
 | 33. Workflow Edit Safety | 2/2 | 5 min | 5 min |
 | 34. Agentic Workflow Editing | 3/3 | 13 min | 4.3 min |
-| 35. Large Workflow Handling | 1/3 | 3 min | 3 min |
+| 35. Large Workflow Handling | 3/3 | 18 min | 6 min |
 
 **Recent Trend:**
-- Last 5 plans: 5 min, 8 min, <1 min, 10 min, 3 min
-- Trend: Phase 35 plan 01 complete - binary stripping and rich context system implemented with TDD
+- Last 5 plans: 8 min, <1 min, 10 min, 3 min, 10 min, 5 min
+- Trend: Phase 35 complete - large workflow handling with selection-aware chat context (TDD + execution)
 
 ## Accumulated Context
 
@@ -215,6 +215,6 @@ Recent decisions affecting current work:
 ## Session Continuity
 
 Last session: 2026-01-31
-Stopped at: Completed Phase 35 Plan 02 (Selection-Aware Subgraph Extraction)
+Stopped at: Completed Phase 35 Plan 03 (Client-side wiring and selection chip) - Phase 35 COMPLETE
 Resume file: None
-Next action: Proceed to plan 35-03 (Chat Context Builder Integration) or continue with parallel plan 35-01
+Next action: Phase 35 completes Milestone v1.4 (Agentic Workflow Builder). Ready for Milestone v1.5 (Store Refactoring) or new priorities.

.planning/phases/35-large-workflow-handling/35-03-SUMMARY.md

@@ -0,0 +1,125 @@
+---
+phase: 35-large-workflow-handling
+plan: 03
+subsystem: chat-integration
+tags: [client-side, selection-ui, api-integration, subgraph]
+requires:
+  - src/lib/chat/subgraphExtractor.ts (extractSubgraph)
+  - src/lib/chat/contextBuilder.ts (stripBinaryData)
+provides:
+  - Selection-aware chat workflow state
+  - Selection chip UI in ChatPanel
+  - API-side subgraph context building
+affects:
+  - src/components/WorkflowCanvas.tsx (chatWorkflowState computation)
+  - src/components/ChatPanel.tsx (selection UI, error handling)
+  - src/app/api/chat/route.ts (subgraph-aware context)
+  - src/lib/chat/tools.ts (system prompt)
+tech-stack:
+  - React
+  - TypeScript
+  - Next.js API Routes
+  - AI SDK v6
+key-files:
+  - src/components/WorkflowCanvas.tsx (chatWorkflowState with stripped data)
+  - src/components/ChatPanel.tsx (selection chip UI)
+  - src/app/api/chat/route.ts (subgraph extraction)
+  - src/lib/chat/tools.ts (system prompt updates)
+key-decisions:
+  - Client-side binary stripping (not API-side) for smaller HTTP payloads
+  - selectedNodeIds derived from node.selected state
+  - Selection chip dismissible per session (resets when selection changes)
+  - Server-side subgraph extraction in API route
+  - System prompt includes metadata placeholder notes
+  - 413 error handling for oversized payloads
+duration: 5 minutes
+completed: 2026-01-31
+---
+
+# Client-side wiring, ChatPanel selection chip, API subgraph integration
+
+## Performance
+
+**Started:** 2026-01-31
+**Completed:** 2026-01-31
+**Duration:** ~5 minutes
+**Code output:** 4 files modified
+**Efficiency:** Clean execution phase, all tasks completed successfully
+
+## Accomplishments
+
+Completed the full integration of selection-aware chat context for large workflows:
+
+1. **Client-side binary stripping** - `chatWorkflowState` uses `stripBinaryData()` to create rich but compact node data, removing base64 images/videos and large arrays while preserving all parameters and settings
+
+2. **Selection-aware subgraph scoping** - `selectedNodeIds` computed from `nodes.filter(n => n.selected)` and passed to chat API for focused context
+
+3. **Selection chip UI** - Dismissible "Focused on N selected nodes" chip appears above chat input when nodes are selected, providing clear visual feedback
+
+4. **API-side subgraph extraction** - `extractSubgraph()` called in chat API route before context building, enabling detailed focus on selected nodes with lightweight summaries of the rest
+
+5. **Error handling** - Oversized payload errors return friendly 413 message to user
+
+6. **System prompt updates** - Enhanced with metadata placeholder notes and subgraph summary section to guide LLM understanding of stripped context
+
+## Task Commits
+
+| Task | Commit | Description |
+|------|--------|-------------|
+| 1 | aaafef4 | feat(35-03): rewrite chatWorkflowState with selection context |
+| 2 | 89fca5f | feat(35-03): update API route and system prompt for subgraph-aware context |
+| 3 | (checkpoint) | Human verification - approved by user |
+
+## Files Created/Modified
+
+**Created:**
+- None (all modifications to existing files)
+
+**Modified:**
+- `src/components/WorkflowCanvas.tsx` - Rich stripped `chatWorkflowState` with `selectedNodeIds`
+- `src/components/ChatPanel.tsx` - Selection chip UI, `selectedNodeIds` forwarding, error handling
+- `src/app/api/chat/route.ts` - Subgraph-aware context building, 413 error handling
+- `src/lib/chat/tools.ts` - System prompt with metadata awareness and subgraph summary
+
+## Decisions Made
+
+1. **Client-side stripping** - Call `stripBinaryData()` in WorkflowCanvas (not API-side) to reduce HTTP payload size before network transmission
+
+2. **Selection derivation** - Compute `selectedNodeIds` from `nodes.filter(n => n.selected).map(n => n.id)` rather than maintaining separate state
+
+3. **Chip dismissibility** - Selection chip dismissible per session using local `useState`, resets when selection changes (chip reappears)
+
+4. **Server-side extraction** - Subgraph extraction happens in API route (not client-side) to keep client bundle smaller and logic centralized
+
+5. **Metadata placeholders** - System prompt explicitly notes that `[image: ...]`, `[video: ...]`, `[N image(s)]` are non-editable metadata placeholders representing stripped binary data
+
+6. **Error handling** - 413 status for token/size issues with friendly message: "Workflow too large to send. Try selecting fewer nodes."
+
+## Deviations from Plan
+
+None. Implementation followed plan exactly:
+- Binary stripping integrated client-side
+- Selection chip UI implemented as specified
+- API route modified for subgraph-aware context
+- System prompt enhanced with metadata notes
+- All checkpoint requirements met
+
+## Issues Encountered
+
+None. Clean execution with no blockers. All tasks completed successfully and checkpoint approved.
+
+## Next Phase Readiness
+
+**Phase 35 complete** - All 3 plans finished:
+- Plan 01: Binary stripping and rich workflow context (TDD)
+- Plan 02: Selection-aware subgraph extraction (TDD)
+- Plan 03: Client-side wiring and integration (execution)
+
+**System capabilities:**
+- Chat agent receives rich stripped node data with all parameters
+- Users can select nodes to focus LLM attention on specific workflow areas
+- Selection chip provides clear visual feedback
+- Subgraph extraction enables scalable context for large workflows (50+ nodes)
+- Error handling prevents silent failures from oversized payloads
+
+**Ready for next milestone** - Phase 35 completes Milestone v1.4 (Agentic Workflow Builder). Ready to proceed to Milestone v1.5 (Store Refactoring) or address any new priorities.