n8n MCP Server

Instructions

Implementation Reference

• src/index.ts:420-425 (handler)

  Main MCP tool handler: resolves workflow ID alias, activates via n8nClient, adds numeric alias to response, returns JSON-formatted workflow.

  private async handleActivateWorkflow(args: { id: string | number }) {
    const id = this.resolveWorkflowId(args.id);
    const workflow = await this.n8nClient.activateWorkflow(id);
    this.withAlias(workflow);
    return { content: [{ type: 'text', text: JSON.stringify(jsonSuccess(workflow), null, 2) }] };
  }

• src/n8n-client.ts:221-225 (helper)

  N8nClient helper: Performs the core HTTP POST to n8n API /workflows/{id}/activate endpoint and normalizes the response.

  async activateWorkflow(id: string | number): Promise<N8nWorkflow> {
    const response = await this.api.post<N8nApiResponse<N8nWorkflow> | N8nWorkflow>(`/workflows/${id}/activate`);
    const payload: any = response.data as any;
    return (payload && typeof payload === 'object' && 'data' in payload) ? payload.data : payload;
  }

• src/index.ts:74-74 (registration)

  Tool registration in list_tools response: defines name, description, and input schema (id: string|number required).

  { name: 'activate_workflow', description: 'Activate an n8n workflow', inputSchema: { type: 'object', properties: { id: { oneOf: [{ type: 'string' }, { type: 'number' }] } }, required: ['id'] } },

• src/index.ts:236-237 (registration)

  Dispatch routing in CallToolRequest handler: matches tool name and invokes the handler method.

  case 'activate_workflow':
    return await this.handleActivateWorkflow(request.params.arguments as { id: string | number });