docs(06): create phase plan for n8n API access

Phase 6: n8n API Access
- 1 plan in 1 wave
- Covers API-01 through API-04 requirements
- Human checkpoint for API key creation + automated verification
- Fixed: Use PUT (not PATCH) per current n8n docs

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

.planning/phases/06-n8n-api-access/06-01-PLAN.md

@@ -115,15 +115,16 @@ Output: Verified API access with documented curl commands for workflow CRUD and
          -H "accept: application/json" \
          -H "X-N8N-API-KEY: ${N8N_API_KEY}")
 
-       # PATCH with same nodes/connections (no-op update to verify write access)
-       echo "$WORKFLOW" | jq '{nodes: .nodes, connections: .connections}' | \
-         curl -s -X PATCH "${N8N_HOST}/api/v1/workflows/{WORKFLOW_ID}" \
+       # PUT with same nodes/connections (no-op update to verify write access)
+       # Note: n8n public API uses PUT (full update), not PATCH
+       echo "$WORKFLOW" | jq '{name: .name, nodes: .nodes, connections: .connections, settings: .settings}' | \
+         curl -s -X PUT "${N8N_HOST}/api/v1/workflows/{WORKFLOW_ID}" \
            -H "accept: application/json" \
            -H "X-N8N-API-KEY: ${N8N_API_KEY}" \
            -H "Content-Type: application/json" \
            -d @- | jq '.updatedAt'
        ```
-       Expected: Updated timestamp returned (workflow accepted the PATCH)
+       Expected: Updated timestamp returned (workflow accepted the PUT)
 
     4. **API-04: Execution History** - View recent workflow runs
        ```bash
@@ -145,13 +146,13 @@ Output: Verified API access with documented curl commands for workflow CRUD and
     All 4 curl commands return successful JSON responses:
     - GET /api/v1/workflows returns 200 with workflow list
     - GET /api/v1/workflows/{id} returns 200 with full workflow JSON
-    - PATCH /api/v1/workflows/{id} returns 200 with updated timestamp
+    - PUT /api/v1/workflows/{id} returns 200 with updated timestamp
     - GET /api/v1/executions returns 200 with execution records
   </verify>
   <done>
     - API-01: API key authenticates successfully (no 401/403)
     - API-02: Can read full workflow JSON including nodes and connections
-    - API-03: Can push workflow changes (PATCH accepted, updatedAt changed)
+    - API-03: Can push workflow changes (PUT accepted, updatedAt changed)
     - API-04: Can view execution history with status for each run
     - .env.n8n-api created with credentials (gitignored)
   </done>
@@ -171,7 +172,7 @@ Run the 4 verification curl commands and confirm:
 All 4 requirements verified with working curl commands:
 - API-01: n8n API key created and accessible (curl returns 200)
 - API-02: Claude Code can read workflow via API (full JSON retrieved)
-- API-03: Claude Code can update workflow via API (PATCH succeeds)
+- API-03: Claude Code can update workflow via API (PUT succeeds)
 - API-04: Claude Code can view execution history and logs (executions listed)
 </success_criteria>
 

.planning/phases/06-n8n-api-access/06-RESEARCH.md

@@ -103,7 +103,7 @@ const updated = await n8nClient.patch(`/api/v1/workflows/${workflowId}`, {
 **When to use:** Making incremental changes to existing workflows
 **Example:**
 ```javascript
-// Source: Community workflow manager patterns
+// Source: n8n official docs - public API uses PUT (full replace)
 async function updateWorkflowNode(workflowId, nodeName, newParams) {
   // 1. Fetch current workflow
   const { data: workflow } = await n8nClient.get(`/api/v1/workflows/${workflowId}`);
@@ -114,8 +114,9 @@ async function updateWorkflowNode(workflowId, nodeName, newParams) {
     node.parameters = { ...node.parameters, ...newParams };
   }
 
-  // 3. Push updated workflow
-  const { data: updated } = await n8nClient.patch(`/api/v1/workflows/${workflowId}`, {
+  // 3. Push updated workflow (PUT requires full workflow body)
+  const { data: updated } = await n8nClient.put(`/api/v1/workflows/${workflowId}`, {
+    name: workflow.name,
     nodes: workflow.nodes,
     connections: workflow.connections,
     settings: workflow.settings
@@ -275,16 +276,19 @@ curl -X GET 'http://localhost:5678/api/v1/workflows/1' \
   -H 'X-N8N-API-KEY: n8n_api_...'
 ```
 
-### Update Workflow (Partial)
+### Update Workflow (Full Replace)
 ```bash
-# Source: Community workflow manager patterns
-curl -X PATCH 'http://localhost:5678/api/v1/workflows/1' \
+# Source: n8n official docs - public API uses PUT for workflow updates
+# Note: Must include name, nodes, connections, settings (full workflow body)
+curl -X PUT 'http://localhost:5678/api/v1/workflows/1' \
   -H 'accept: application/json' \
   -H 'X-N8N-API-KEY: n8n_api_...' \
   -H 'Content-Type: application/json' \
   -d '{
+    "name": "Workflow Name",
     "nodes": [...updated nodes array...],
-    "connections": {...updated connections...}
+    "connections": {...updated connections...},
+    "settings": {}
   }'
 ```