n8n MCP Server

Instructions

Implementation Reference

• src/index.ts:71-71 (registration)

  Registration of the 'create_workflow' MCP tool, including input schema definition

  { name: 'create_workflow', description: 'Create a new n8n workflow', inputSchema: { type: 'object', properties: { name: { type: 'string' }, nodes: { type: 'array', items: { type: 'object' } }, connections: { type: 'object' }, active: { type: 'boolean', default: false }, tags: { type: 'array', items: { type: 'string' } } }, required: ['name', 'nodes', 'connections'] } },

• src/index.ts:400-404 (handler)

  MCP server handler for 'create_workflow': calls N8nClient.createWorkflow, adds numeric ID alias, returns JSON response

  private async handleCreateWorkflow(args: Omit<N8nWorkflow, 'id'>) {
    const workflow = await this.n8nClient.createWorkflow(args);
    this.withAlias(workflow);
    return { content: [{ type: 'text', text: JSON.stringify(jsonSuccess(workflow), null, 2) }] };
  }

• src/index.ts:230-231 (handler)

  Switch case in CallToolRequestHandler dispatching 'create_workflow' calls to the handler method

  case 'create_workflow':
    return await this.handleCreateWorkflow(request.params.arguments as Omit<N8nWorkflow, 'id'>);

• src/n8n-client.ts:175-194 (helper)

  Core N8nClient implementation: resolves credential aliases, sanitizes workflow (settings/tags/active), POSTs to n8n /workflows endpoint

  async createWorkflow(workflow: Omit<N8nWorkflow, 'id'>): Promise<N8nWorkflow> {
    // Resolve credential aliases before creating the workflow
    await this.resolveCredentialsInWorkflow(workflow);
    // Ensure required fields expected by n8n API
    if ((workflow as any).settings == null) {
      (workflow as any).settings = {};
    }
    // Some n8n deployments may not accept non-numeric tag values on create.
    // If tags are provided as strings (names), omit them here; users can set numeric tag IDs via setWorkflowTags.
    if (Array.isArray((workflow as any).tags) && (workflow as any).tags.some((t: any) => typeof t !== 'number')) {
      delete (workflow as any).tags;
    }
    // 'active' is managed via dedicated activate/deactivate endpoints; omit on create
    if ('active' in (workflow as any)) {
      delete (workflow as any).active;
    }
    const response = await this.api.post<N8nApiResponse<N8nWorkflow> | N8nWorkflow>('/workflows', workflow);
    const payload: any = response.data as any;
    return (payload && typeof payload === 'object' && 'data' in payload) ? payload.data : payload;
  }

• src/types.ts:1-13 (schema)

  TypeScript interface N8nWorkflow defining the structure expected for create_workflow input (Omit<..., 'id'>)

  export interface N8nWorkflow {
    id?: string | number;
    name: string;
    nodes: N8nNode[];
    connections: N8nConnections;
    active?: boolean;
    settings?: Record<string, any>;
    staticData?: Record<string, any>;
    tags?: string[];
    pinData?: Record<string, any>;
    versionId?: string;
    meta?: Record<string, any>;
  }