McFlow

Instructions

Implementation Reference

• src/workflows/operations.ts:4-45 (handler)

  Core implementation of the add_node tool: reads workflow JSON, appends the provided node (with auto-positioning if not specified), persists changes to file, returns success message.

  export async function addNodeToWorkflow(
    workflowsPath: string,
    workflowPath: string,
    node: any,
    position?: any
  ): Promise<any> {
    try {
      const fullPath = path.join(workflowsPath, workflowPath);
      const content = await fs.readFile(fullPath, 'utf-8');
      const workflow = JSON.parse(content);
  
      if (!workflow.nodes) {
        workflow.nodes = [];
      }
  
      if (position) {
        node.position = [position.x || 250, position.y || 300];
      } else {
        const lastNode = workflow.nodes[workflow.nodes.length - 1];
        if (lastNode && lastNode.position) {
          node.position = [lastNode.position[0] + 250, lastNode.position[1]];
        } else {
          node.position = [250, 300];
        }
      }
  
      workflow.nodes.push(node);
  
      await fs.writeFile(fullPath, JSON.stringify(workflow, null, 2));
  
      return {
        content: [
          {
            type: 'text',
            text: `Node added to workflow: ${node.id}`,
          },
        ],
      };
    } catch (error) {
      throw new Error(`Failed to add node: ${error}`);
    }
  }

• src/tools/handler.ts:82-88 (handler)

  ToolHandler switch case that routes 'add_node' tool invocations to the addNodeToWorkflow implementation, passing workflowsPath and parsed arguments.

  case 'add_node':
    return await addNodeToWorkflow(
      this.workflowsPath,
      args?.path as string,
      args?.node as any,
      args?.position as any
    );

• src/tools/registry.ts:122-147 (registration)

  Registers the 'add_node' MCP tool including its name, description, and input schema validation.

  {
    name: 'add_node',
    description: 'Add a REAL n8n node to workflow (no mock/placeholder nodes allowed)',
    inputSchema: {
      type: 'object',
      properties: {
        path: {
          type: 'string',
          description: 'Path to the workflow file',
        },
        node: {
          type: 'object',
          description: 'The node to add',
        },
        position: {
          type: 'object',
          properties: {
            x: { type: 'number' },
            y: { type: 'number' },
          },
          description: 'Position for the new node',
        },
      },
      required: ['path', 'node'],
    },
  },

• src/tools/registry.ts:125-146 (schema)

  Input schema defining parameters for add_node: path (required), node (required), optional position with x/y coordinates.

  inputSchema: {
    type: 'object',
    properties: {
      path: {
        type: 'string',
        description: 'Path to the workflow file',
      },
      node: {
        type: 'object',
        description: 'The node to add',
      },
      position: {
        type: 'object',
        properties: {
          x: { type: 'number' },
          y: { type: 'number' },
        },
        description: 'Position for the new node',
      },
    },
    required: ['path', 'node'],
  },