Instrument MCP server with Sentry Insights spans

packages/worker/src/mcp/index.node.test.ts

@@ -0,0 +1,29 @@
+import type * as SentryCloudflare from '@sentry/cloudflare'
+import { expect, test, vi } from 'vitest'
+
+const sentryMock = vi.hoisted(() => ({
+	wrapMcpServerWithSentry: vi.fn((server: unknown) => server),
+}))
+
+vi.mock('@sentry/cloudflare', async (importOriginal) => {
+	const actual = await importOriginal<typeof SentryCloudflare>()
+	return {
+		...actual,
+		wrapMcpServerWithSentry: sentryMock.wrapMcpServerWithSentry,
+	}
+})
+
+test('createKodyMcpServer applies Sentry MCP instrumentation without payload recording', async () => {
+	const { createKodyMcpServer } = await import('./sentry-mcp-server.ts')
+
+	const server = createKodyMcpServer({
+		instructions: 'test instructions',
+	})
+
+	expect(server).toBeDefined()
+	expect(sentryMock.wrapMcpServerWithSentry).toHaveBeenCalledTimes(1)
+	expect(sentryMock.wrapMcpServerWithSentry).toHaveBeenCalledWith(server, {
+		recordInputs: false,
+		recordOutputs: false,
+	})
+})

packages/worker/src/mcp/index.ts

@@ -1,7 +1,7 @@
 import * as Sentry from '@sentry/cloudflare'
 import { type exports as workerExports } from 'cloudflare:workers'
 import { invariant } from '@epic-web/invariant'
-import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js'
+import { type McpServer } from '@modelcontextprotocol/sdk/server/mcp.js'
 import { CfWorkerJsonSchemaValidator } from '@modelcontextprotocol/sdk/validation/cfworker-provider.js'
 import { McpAgent } from 'agents/mcp'
 import { buildSentryOptions } from '../sentry-options.ts'
@@ -13,6 +13,7 @@ import {
 	type RemoteConnectorInstructionSummary,
 } from './server-instructions.ts'
 import { registerTools } from './register-tools.ts'
+import { createKodyMcpServer } from './sentry-mcp-server.ts'
 import { getMcpUserServerInstructions } from './user-server-instructions-repo.ts'
 import { createRemoteConnectorMcpClient } from '#worker/remote-connector/client.ts'
 import { remoteConnectorDomainId } from '#worker/remote-connector/remote-domain-id.ts'
@@ -26,11 +27,6 @@ export type Props = McpServerProps
 
 export { conversationIdGuidance }
 
-const serverImplementation = {
-	name: 'kody-mcp',
-	version: '1.0.0',
-} as const
-
 async function loadRemoteConnectorInstructionSummaries(input: {
 	env: Env
 	caller: McpCallerContext
@@ -88,7 +84,7 @@ class MCPBase extends McpAgent<Env, State, Props> {
 				caller,
 			}),
 		])
-		this.server = new McpServer(serverImplementation, {
+		this.server = createKodyMcpServer({
 			instructions: buildMcpServerInstructions({
 				userOverlay: overlay,
 				remoteConnectors,

packages/worker/src/mcp/resources/generated-ui-app-resource.ts

@@ -1,3 +1,4 @@
+import * as Sentry from '@sentry/cloudflare'
 import {
 	RESOURCE_MIME_TYPE,
 	registerAppResource,
@@ -41,6 +42,10 @@ export async function registerGeneratedUiAppResource(
 			description: generatedUiAppResource.description,
 		},
 		async () => {
+			Sentry.getActiveSpan()?.setAttribute(
+				'mcp.resource.uri',
+				generatedUiRuntimeResourceUri,
+			)
 			const claudeWidgetDomain = await computeClaudeWidgetDomain(mcpServerUrl)
 			const uiResource = createUIResource({
 				uri: generatedUiRuntimeResourceUri,

packages/worker/src/mcp/sentry-mcp-server.ts

@@ -0,0 +1,19 @@
+import * as Sentry from '@sentry/cloudflare'
+import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js'
+
+const serverImplementation = {
+	name: 'kody-mcp',
+	version: '1.0.0',
+} as const
+
+export function createKodyMcpServer(
+	options: ConstructorParameters<typeof McpServer>[1],
+) {
+	return Sentry.wrapMcpServerWithSentry(
+		new McpServer(serverImplementation, options),
+		{
+			recordInputs: false,
+			recordOutputs: false,
+		},
+	)
+}

packages/worker/src/test-support/sentry-cloudflare-stub.ts

@@ -53,6 +53,17 @@ export async function startSpan<TResult>(
 	})
 }
 
+export function getActiveSpan() {
+	return undefined
+}
+
+export function wrapMcpServerWithSentry<TServer>(
+	server: TServer,
+	_options?: unknown,
+) {
+	return server
+}
+
 export function withSentry<THandler>(
 	_optionsCallback: unknown,
 	handler: THandler,