first commit

packages/@n8n/nodes-langchain/nodes/mcp/McpClient/resourceMapping.ts

@@ -0,0 +1,48 @@
+import type { ILoadOptionsFunctions, ResourceMapperFields } from 'n8n-workflow';
+import { NodeOperationError } from 'n8n-workflow';
+
+import { convertJsonSchemaToResourceMapperFields } from './utils';
+import type { McpAuthenticationOption, McpServerTransport } from '../shared/types';
+import {
+	getAuthHeaders,
+	connectMcpClient,
+	getAllTools,
+	tryRefreshOAuth2Token,
+	mapToNodeOperationError,
+} from '../shared/utils';
+
+export async function getToolParameters(
+	this: ILoadOptionsFunctions,
+): Promise<ResourceMapperFields> {
+	const toolId = this.getNodeParameter('tool', 0, {
+		extractValue: true,
+	}) as string;
+	const authentication = this.getNodeParameter('authentication') as McpAuthenticationOption;
+	const serverTransport = this.getNodeParameter('serverTransport') as McpServerTransport;
+	const endpointUrl = this.getNodeParameter('endpointUrl') as string;
+	const node = this.getNode();
+	const { headers } = await getAuthHeaders(this, authentication);
+	const client = await connectMcpClient({
+		serverTransport,
+		endpointUrl,
+		headers,
+		name: node.type,
+		version: node.typeVersion,
+		onUnauthorized: async (headers) => await tryRefreshOAuth2Token(this, authentication, headers),
+	});
+
+	if (!client.ok) {
+		throw mapToNodeOperationError(node, client.error);
+	}
+
+	const result = await getAllTools(client.result);
+	const tool = result.find((tool) => tool.name === toolId);
+	if (!tool) {
+		throw new NodeOperationError(this.getNode(), 'Tool not found');
+	}
+
+	const fields = convertJsonSchemaToResourceMapperFields(tool.inputSchema);
+	return {
+		fields,
+	};
+}