feat(node): Add MCP server auto instrumentation

Author: Luca Forstner

packages/node/src/integrations/mcp-server.ts

@@ -0,0 +1,79 @@
+import type { InstrumentationConfig } from '@opentelemetry/instrumentation';
+import { isWrapped } 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, wrapMcpServerWithSentry } from '@sentry/core';
+
+const supportedVersions = ['>=1.9.0 <2'];
+
+interface MCPServerInstance {
+  tool: (toolName: string, toolSchema: unknown, handler: (...args: unknown[]) => unknown) => void;
+}
+
+interface MCPSdkModuleDef {
+  McpServer: new (...args: unknown[]) => MCPServerInstance;
+}
+
+/**
+ * Sentry instrumentation for MCP Servers (`@modelcontextprotocol/sdk` package)
+ */
+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 moduleDef = new InstrumentationNodeModuleDefinition('@modelcontextprotocol/sdk', supportedVersions);
+
+    moduleDef.files.push(
+      new InstrumentationNodeModuleFile(
+        '@modelcontextprotocol/sdk/server/mcp.js',
+        supportedVersions,
+        (moduleExports: MCPSdkModuleDef) => {
+          if (isWrapped(moduleExports.McpServer)) {
+            this._unwrap(moduleExports, 'McpServer');
+          }
+
+          this._wrap(moduleExports, 'McpServer', originalMcpServerClass => {
+            return new Proxy(originalMcpServerClass, {
+              construct(McpServerClass, mcpServerConstructorArgArray) {
+                const mcpServerInstance = new McpServerClass(...mcpServerConstructorArgArray);
+
+                return wrapMcpServerWithSentry(mcpServerInstance);
+              },
+            });
+          });
+
+          return moduleExports;
+        },
+        (moduleExports: MCPSdkModuleDef) => {
+          this._unwrap(moduleExports, 'McpServer');
+        },
+      ),
+    );
+
+    return [moduleDef];
+  }
+}
+const INTEGRATION_NAME = 'MCP';
+
+const instrumentMcp = generateInstrumentOnce('MCP', () => {
+  return new McpInstrumentation();
+});
+
+/**
+ * Integration capturing tracing data for MCP servers (via the `@modelcontextprotocol/sdk` package).
+ */
+export const mcpIntegration = defineIntegration(() => {
+  return {
+    name: INTEGRATION_NAME,
+    setupOnce() {
+      instrumentMcp();
+    },
+  };
+});

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(),
   ];
 }