feat(node): Add mcp server instrumentation

Author: lforst

Diff for: packages/node/src/integrations/mcp-server.ts

@@ -0,0 +1,124 @@
+// import { isWrapped } from '@opentelemetry/core';
+import type { InstrumentationConfig } from '@opentelemetry/instrumentation';
+import { InstrumentationNodeModuleFile } from '@opentelemetry/instrumentation';
+import { InstrumentationBase, InstrumentationNodeModuleDefinition } from '@opentelemetry/instrumentation';
+import { SDK_VERSION } from '@sentry/core';
+import { generateInstrumentOnce } from '../otel/instrument';
+import { defineIntegration } from '@sentry/core';
+
+const supportedVersions = ['> 0.0.1'];
+
+interface MCPServerInstance {
+  tool: (toolName: string, toolSchema: unknown, handler: (...args: unknown[]) => unknown) => void;
+}
+
+interface MCPSdkModuleDef {
+  McpServer: new (...args: unknown[]) => MCPServerInstance;
+}
+
+const perms = [
+  '@modelcontextprotocol/sdk',
+  '@modelcontextprotocol/sdk/server/mcp',
+  '@modelcontextprotocol/sdk/server/mcp.js',
+  '@modelcontextprotocol/sdk/dist/esm/server/mcp.js',
+  '@modelcontextprotocol/sdk/dist/cjs/server/mcp.js',
+  '@modelcontextprotocol/sdk/dist/esm/server/mcp',
+  '@modelcontextprotocol/sdk/dist/cjs/server/mcp',
+  './server/mcp',
+  './server/mcp.js',
+];
+
+/**
+ * Todo
+ */
+export class McpInstrumentation extends InstrumentationBase {
+  public constructor(config: InstrumentationConfig = {}) {
+    super('sentry-modelcontextprotocol-sdk', SDK_VERSION, config);
+  }
+
+  /**
+   * Initializes the instrumentation by defining the modules to be patched.
+   */
+  public init(): InstrumentationNodeModuleDefinition[] {
+    const moduleDefs: InstrumentationNodeModuleDefinition[] = [];
+
+    perms.forEach(modulePath => {
+      const moduleDef = new InstrumentationNodeModuleDefinition(
+        modulePath,
+        supportedVersions,
+        (moduleExports: MCPSdkModuleDef) => {
+          console.log('module wrap', modulePath, moduleExports);
+          return moduleExports;
+        },
+        (moduleExports: MCPSdkModuleDef) => {
+          this._unwrap(moduleExports, 'McpServer');
+        },
+      );
+
+      perms.forEach(filePath => {
+        moduleDef.files.push(
+          new InstrumentationNodeModuleFile(
+            filePath,
+            supportedVersions,
+            (moduleExports: MCPSdkModuleDef) => {
+              console.log('file wrap', filePath, moduleExports);
+              return moduleExports;
+            },
+            (moduleExports: MCPSdkModuleDef) => {
+              this._unwrap(moduleExports, 'McpServer');
+            },
+          ),
+        );
+      });
+
+      moduleDefs.push(moduleDef);
+    });
+
+    return moduleDefs;
+  }
+}
+const INTEGRATION_NAME = 'MCP';
+
+const instrumentMcp = generateInstrumentOnce('MCP', () => {
+  return new McpInstrumentation();
+});
+
+/**
+ * Integration capturing tracing data for MCP servers.
+ */
+export const mcpIntegration = defineIntegration(() => {
+  return {
+    name: INTEGRATION_NAME,
+    setupOnce() {
+      instrumentMcp();
+    },
+  };
+});
+
+// console.log('FILE called', moduleExports);
+
+// if (isWrapped(moduleExports.McpServer)) {
+//   this._unwrap(moduleExports, 'McpServer');
+// }
+
+// console.log('WRAP called');
+
+// this._wrap(moduleExports, 'McpServer', originalMcpServerClass => {
+//   console.log('WRAPPING', originalMcpServerClass);
+//   return new Proxy(originalMcpServerClass, {
+//     construct(McpServerClass, mcpServerConstructorArgArray) {
+//       const mcpServerInstance = new McpServerClass(...mcpServerConstructorArgArray);
+
+//       console.log('MCP Server constructed');
+
+//       mcpServerInstance.tool = new Proxy(mcpServerInstance.tool, {
+//         apply(toolTarget, toolThisArg, toolArgArray) {
+//           console.log('Tool handler called!: ', toolArgArray[0]);
+//           return toolTarget.apply(toolThisArg, toolArgArray);
+//         },
+//       });
+
+//       return mcpServerInstance;
+//     },
+//   });
+// });

Diff for: packages/node/src/sdk/index.ts

@@ -39,6 +39,7 @@ import { envToBool } from '../utils/envToBool';
 import { defaultStackParser, getSentryRelease } from './api';
 import { NodeClient } from './client';
 import { initOpenTelemetry, maybeInitializeEsmLoader } from './initOtel';
+import { mcpIntegration } from '../integrations/mcp-server';
 
 function getCjsOnlyIntegrations(): Integration[] {
   return isCjs() ? [modulesIntegration()] : [];
@@ -69,6 +70,7 @@ export function getDefaultIntegrationsWithoutPerformance(): Integration[] {
     nodeContextIntegration(),
     childProcessIntegration(),
     processSessionIntegration(),
+    mcpIntegration(),
     ...getCjsOnlyIntegrations(),
   ];
 }