MCP- N8N

Instructions

Implementation Reference

• src/index.ts:928-958 (handler)

  MCP tool handler for 'get-workflow': validates clientId, retrieves N8nClient instance, calls client.getWorkflow(id), and returns the workflow JSON or error.

  case "get-workflow": {
    const { clientId, id } = args as { clientId: string; id: string };
    const client = clients.get(clientId);
    if (!client) {
      return {
        content: [{
          type: "text",
          text: "Client not initialized. Please run init-n8n first.",
        }],
        isError: true
      };
    }
  
    try {
      const workflow = await client.getWorkflow(id);
      return {
        content: [{
          type: "text",
          text: JSON.stringify(workflow, null, 2),
        }]
      };
    } catch (error) {
      return {
        content: [{
          type: "text",
          text: error instanceof Error ? error.message : "Unknown error occurred",
        }],
        isError: true
      };
    }
  }

• src/index.ts:424-434 (registration)

  Tool registration in ListTools response, defining name, description, and input schema for 'get-workflow'.

    name: "get-workflow",
    description: "Retrieve a workflow by ID. Use after list-workflows to get detailed information about a specific workflow. IMPORTANT: Arguments must be provided as compact, single-line JSON without whitespace or newlines.",
    inputSchema: {
      type: "object",
      properties: {
        clientId: { type: "string" },
        id: { type: "string" }
      },
      required: ["clientId", "id"]
    }
  },

• src/index.ts:160-162 (helper)

  N8nClient helper method that performs the actual API call to fetch workflow by ID via makeRequest.

  async getWorkflow(id: string): Promise<N8nWorkflow> {
    return this.makeRequest<N8nWorkflow>(`/workflows/${id}`);
  }

• src/index.ts:24-31 (schema)

  TypeScript interface defining the structure of an N8n workflow object returned by the API.

  interface N8nWorkflow {
    id: number;
    name: string;
    active: boolean;
    createdAt: string;
    updatedAt: string;
    tags: string[];
  }