@n8n/n8n-nodes-langchain
Version:
200 lines • 9.41 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.McpTrigger = void 0;
const McpServer_1 = require("./McpServer");
const error_1 = require("n8n-nodes-base/dist/nodes/Webhook/error");
const utils_1 = require("n8n-nodes-base/dist/nodes/Webhook/utils");
const n8n_workflow_1 = require("n8n-workflow");
const helpers_1 = require("../../../utils/helpers");
const MCP_SSE_SETUP_PATH = 'sse';
const MCP_SSE_MESSAGES_PATH = 'messages';
class McpTrigger extends n8n_workflow_1.Node {
constructor() {
super(...arguments);
this.description = {
displayName: 'MCP Server Trigger',
name: 'mcpTrigger',
icon: {
light: 'file:../mcp.svg',
dark: 'file:../mcp.dark.svg',
},
group: ['trigger'],
version: [1, 1.1, 2],
description: 'Expose n8n tools as an MCP Server endpoint',
activationMessage: 'You can now connect your MCP Clients to the URL, using SSE or Streamable HTTP transports.',
defaults: {
name: 'MCP Server Trigger',
},
codex: {
categories: ['AI', 'Core Nodes'],
subcategories: {
AI: ['Root Nodes', 'Model Context Protocol'],
'Core Nodes': ['Other Trigger Nodes'],
},
alias: ['Model Context Protocol', 'MCP Server'],
resources: {
primaryDocumentation: [
{
url: 'https://docs.n8n.io/integrations/builtin/core-nodes/n8n-nodes-langchain.mcptrigger/',
},
],
},
},
triggerPanel: {
header: 'Listen for MCP events',
executionsHelp: {
inactive: "This trigger has two modes: test and production.<br /><br /><b>Use test mode while you build your workflow</b>. Click the 'execute step' button, then make an MCP request to the test URL. The executions will show up in the editor.<br /><br /><b>Use production mode to run your workflow automatically</b>. Publish the workflow, then make requests to the production URL. These executions will show up in the <a data-key='executions'>executions list</a>, but not the editor.",
active: "This trigger has two modes: test and production.<br /><br /><b>Use test mode while you build your workflow</b>. Click the 'execute step' button, then make an MCP request to the test URL. The executions will show up in the editor.<br /><br /><b>Use production mode to run your workflow automatically</b>. Since your workflow is activated, you can make requests to the production URL. These executions will show up in the <a data-key='executions'>executions list</a>, but not the editor.",
},
activationHint: "Once you've finished building your workflow, run it without having to click this button by using the production URL.",
},
inputs: [
{
type: n8n_workflow_1.NodeConnectionTypes.AiTool,
displayName: 'Tools',
},
],
outputs: [],
credentials: [
{
name: 'httpBearerAuth',
required: true,
displayOptions: {
show: {
authentication: ['bearerAuth'],
},
},
},
{
name: 'httpHeaderAuth',
required: true,
displayOptions: {
show: {
authentication: ['headerAuth'],
},
},
},
],
properties: [
{
displayName: 'Authentication',
name: 'authentication',
type: 'options',
options: [
{ name: 'None', value: 'none' },
{ name: 'Bearer Auth', value: 'bearerAuth' },
{ name: 'Header Auth', value: 'headerAuth' },
],
default: 'none',
description: 'The way to authenticate',
},
{
displayName: 'Path',
name: 'path',
type: 'string',
default: '',
placeholder: 'webhook',
required: true,
description: 'The base path for this MCP server',
},
],
webhooks: [
{
name: 'setup',
httpMethod: 'GET',
responseMode: 'onReceived',
isFullPath: true,
path: `={{$parameter["path"]}}{{parseFloat($nodeVersion)<2 ? '/${MCP_SSE_SETUP_PATH}' : ''}}`,
nodeType: 'mcp',
ndvHideMethod: true,
ndvHideUrl: false,
},
{
name: 'default',
httpMethod: 'POST',
responseMode: 'onReceived',
isFullPath: true,
path: `={{$parameter["path"]}}{{parseFloat($nodeVersion)<2 ? '/${MCP_SSE_MESSAGES_PATH}' : ''}}`,
nodeType: 'mcp',
ndvHideMethod: true,
ndvHideUrl: true,
},
{
name: 'default',
httpMethod: 'DELETE',
responseMode: 'onReceived',
isFullPath: true,
path: '={{$parameter["path"]}}',
nodeType: 'mcp',
ndvHideMethod: true,
ndvHideUrl: true,
},
],
};
}
async webhook(context) {
const webhookName = context.getWebhookName();
const req = context.getRequestObject();
const resp = context.getResponseObject();
try {
await (0, utils_1.validateWebhookAuthentication)(context, 'authentication');
}
catch (error) {
if (error instanceof error_1.WebhookAuthorizationError) {
resp.writeHead(error.responseCode);
resp.end(error.message);
return { noWebhookResponse: true };
}
throw error;
}
const node = context.getNode();
const serverName = node.typeVersion > 1 ? (0, n8n_workflow_1.nodeNameToToolName)(node) : 'n8n-mcp-server';
const mcpServer = McpServer_1.McpServer.instance(context.logger);
if (webhookName === 'setup') {
const postUrl = node.typeVersion < 2
? req.path.replace(new RegExp(`/${MCP_SSE_SETUP_PATH}$`), `/${MCP_SSE_MESSAGES_PATH}`)
: req.path;
const connectedTools = await (0, helpers_1.getConnectedTools)(context, true);
await mcpServer.handleSetupRequest(req, resp, serverName, postUrl, connectedTools);
return { noWebhookResponse: true };
}
else if (webhookName === 'default') {
if (req.method === 'DELETE') {
await mcpServer.handleDeleteRequest(req, resp);
}
else {
const sessionId = mcpServer.getSessionId(req);
context.logger.debug('MCP POST request received for existing session');
if (sessionId) {
const connectedTools = await (0, helpers_1.getConnectedTools)(context, true);
const { wasToolCall, toolCallInfo, messageId, relaySessionId, needsListToolsRelay } = await mcpServer.handlePostMessage(req, resp, connectedTools, serverName);
if (wasToolCall) {
const workflowData = {
...(toolCallInfo && { mcpToolCall: toolCallInfo }),
...(messageId && { mcpMessageId: messageId }),
};
return { noWebhookResponse: true, workflowData: [[{ json: workflowData }]] };
}
if (needsListToolsRelay && relaySessionId && messageId) {
const workflowData = {
mcpListToolsRelay: {
sessionId: relaySessionId,
messageId,
marker: McpServer_1.MCP_LIST_TOOLS_REQUEST_MARKER,
},
};
return { noWebhookResponse: true, workflowData: [[{ json: workflowData }]] };
}
}
else {
const connectedTools = await (0, helpers_1.getConnectedTools)(context, true);
await mcpServer.handleStreamableHttpSetup(req, resp, serverName, connectedTools);
}
}
return { noWebhookResponse: true };
}
return { workflowData: [[{ json: {} }]] };
}
}
exports.McpTrigger = McpTrigger;
//# sourceMappingURL=McpTrigger.node.js.map