update

Instructions

Implementation Reference

• src/workflows/manager.ts:427-492 (handler)

  Main handler function that performs the actual update: preserves workflow metadata (ID, createdAt), writes the new JSON to file, marks as edited, updates documentation and credentials.

  async updateWorkflow(workflowPath: string, workflow: any): Promise<any> {
    try {
      const fullPath = path.join(this.workflowsPath, workflowPath);
      
      // Try to preserve the existing workflow ID if it exists
      try {
        const existingContent = await fs.readFile(fullPath, 'utf-8');
        const existingWorkflow = JSON.parse(existingContent);
        
        // Preserve important metadata from existing workflow
        if (existingWorkflow.id && !workflow.id) {
          workflow.id = existingWorkflow.id;
          console.error(`Preserving workflow ID: ${workflow.id}`);
        }
        if (existingWorkflow.createdAt && !workflow.createdAt) {
          workflow.createdAt = existingWorkflow.createdAt;
        }
        // Always update the updatedAt timestamp
        workflow.updatedAt = new Date().toISOString();
      } catch (readError) {
        // File might not exist yet or might be invalid JSON
        console.error('Could not read existing workflow, creating new');
      }
      
      await fs.writeFile(fullPath, stringifyWorkflowFile(workflow));
      
      // Mark as edited in change tracker
      const relativePath = path.relative(this.workflowsPath, fullPath);
      await this.changeTracker.markEdited(relativePath);
      
      // Update documentation
      const workflowName = path.basename(workflowPath, '.json');
      
      try {
        const customInstructions = await this.documenter.getCustomInstructions();
        await this.documenter.updateWorkflowDocumentation(workflowName, workflow, 'update', customInstructions);
        
        // Extract and update credentials
        const credentials = this.initializer.extractCredentialsFromWorkflow(workflow);
        if (credentials.size > 0) {
          await this.initializer.updateEnvExample(credentials);
        }
        
        // Update README with workflow list
        const allWorkflows = await this.getWorkflowList();
        await this.initializer.updateReadmeWorkflowList(allWorkflows);
      } catch (docError) {
        console.error('Failed to update documentation:', docError);
        // Don't fail the workflow update if documentation fails
      }
      
      return {
        content: [
          {
            type: 'text',
            text: `✅ Workflow Updated!\n\n` +
                  `📁 File: ${workflowPath}\n` +
                  `📝 Name: ${workflowName}\n\n` +
                  `The workflow and documentation have been updated.`,
          },
        ],
      };
    } catch (error) {
      throw new Error(`Failed to update workflow: ${error}`);
    }
  }

• src/tools/handler.ts:42-46 (handler)

  ToolHandler switch case that dispatches 'update' tool calls to WorkflowManager.updateWorkflow

  case 'update':
    return await this.workflowManager.updateWorkflow(
      args?.path as string,
      args?.workflow as any
    );

• src/tools/registry.ts:55-72 (schema)

  Input schema definition for the 'update' tool, specifying path and workflow object as required inputs.

  {
    name: 'update',
    description: 'Update an existing n8n workflow',
    inputSchema: {
      type: 'object',
      properties: {
        path: {
          type: 'string',
          description: 'Path to the workflow file relative to workflows root',
        },
        workflow: {
          type: 'object',
          description: 'The updated workflow JSON object',
        },
      },
      required: ['path', 'workflow'],
    },
  },

• src/server/mcflow.ts:80-85 (registration)

  MCP server registration for tool calls, which invokes ToolHandler.handleTool for any tool including 'update'

  this.server.setRequestHandler(CallToolRequestSchema, async (request) => {
    return await this.toolHandler.handleTool(
      request.params.name,
      request.params.arguments
    );
  });

• src/server/mcflow.ts:76-78 (registration)

  MCP server registration for listing tools, which returns the tool definitions including 'update' from registry.ts

  this.server.setRequestHandler(ListToolsRequestSchema, async () => ({
    tools: getToolDefinitions(),
  }));