n8n MCP Server

Instructions

Implementation Reference

• src/index.ts:498-502 (handler)

  MCP server handler for webhook_urls tool: resolves workflow ID alias and delegates to n8nClient.getWebhookUrls

  private async handleWebhookUrls(args: { workflowId: string | number; nodeId: string }) {
    const workflowId = this.resolveWorkflowId(args.workflowId);
    const urls = await this.n8nClient.getWebhookUrls(workflowId, args.nodeId);
    return { content: [{ type: 'text', text: JSON.stringify(jsonSuccess(urls), null, 2) }] };
  }

• src/n8n-client.ts:753-765 (helper)

  Core implementation: fetches workflow, finds webhook node by ID, validates type and path param, constructs testUrl and productionUrl based on n8n baseUrl

  async getWebhookUrls(workflowId: string | number, nodeId: string): Promise<N8nWebhookUrls> {
    const workflow = await this.getWorkflow(workflowId);
    const webhookNode = workflow.nodes.find((node) => node.id === nodeId);
    if (!webhookNode) throw new Error(`Node with ID '${nodeId}' not found in workflow ${workflowId}`);
    if (webhookNode.type !== 'n8n-nodes-base.webhook') {
      throw new Error(`Node '${nodeId}' is not a webhook node (type: ${webhookNode.type})`);
    }
    const path = webhookNode.parameters?.path || '';
    if (!path) throw new Error(`Webhook node '${nodeId}' does not have a path configured`);
    const testUrl = `${this.baseUrl}/webhook-test/${path}`;
    const productionUrl = `${this.baseUrl}/webhook/${path}`;
    return { testUrl, productionUrl };
  }

• src/index.ts:199-200 (registration)

  Tool registration entry in ListToolsResponse, defines name, description, and input schema

  { name: 'webhook_urls', description: 'Get webhook URLs for a webhook node in a workflow', inputSchema: { type: 'object', properties: { workflowId: { oneOf: [{ type: 'string' }, { type: 'number' }] }, nodeId: { type: 'string' } }, required: ['workflowId', 'nodeId'] } },
  { name: 'run_once', description: 'Execute a workflow manually once and return execution details', inputSchema: { type: 'object', properties: { workflowId: { oneOf: [{ type: 'string' }, { type: 'number' }] }, input: { type: 'object' } }, required: ['workflowId'] } },

• src/types.ts:291-294 (schema)

  TypeScript interface defining the output shape of webhook URLs (testUrl and productionUrl)

  export interface N8nWebhookUrls {
    testUrl: string;
    productionUrl: string;
  }