@@ -14,6 +14,7 @@ Work in this release was contributed by @psh4607, @thijsw, @trinitiwowka, @nehap
   - `DenoMongoose` => `Mongoose`
   - `DenoMysql` => `Mysql`
   - `DenoPostgres` => `Postgres`
+- feat(node): Add first-party Mastra integration ([#23823](https://github.com/getsentry/sentry-javascript/pull/23823)). Enabled by default; disable with `defaultIntegrations: integrations => integrations.filter(i => i.name !== 'Mastra')`.
 - **feat(browser): Add `bfcacheMetricsIntegration` to track back/forward cache health**
 
   The new opt-in `bfcacheMetricsIntegration` emits metrics about browser back/forward cache (bfcache) navigations, so you can
 
@@ -42,8 +42,10 @@
     "@koa/router": "^12.0.1",
     "@langchain/anthropic": "^0.3.10",
     "@langchain/core": "^0.3.80",
-    "@langchain/openai": "^0.5.0",
     "@langchain/langgraph": "^0.2.32",
+    "@langchain/openai": "^0.5.0",
+    "@mastra/core": "1.63.2",
+    "@mastra/observability": "1.17.4",
     "@modelcontextprotocol/client": "^2.0.0",
     "@modelcontextprotocol/server": "^2.0.0",
     "@nestjs/common": "^11",
@@ -53,9 +55,9 @@
     "@prisma/client": "6.15.0",
     "@sentry/aws-serverless": "10.67.0",
     "@sentry/core": "10.67.0",
-    "@sentry/server-utils": "10.67.0",
     "@sentry/hono": "10.67.0",
     "@sentry/node": "10.67.0",
+    "@sentry/server-utils": "10.67.0",
     "@types/mongodb": "^3.6.20",
     "@types/mysql": "^2.15.21",
     "@types/pg": "^8.6.5",
 
@@ -0,0 +1,16 @@
+import * as Sentry from '@sentry/node';
+import { loggingTransport } from '@sentry-internal/node-integration-tests';
+
+Sentry.init({
+  traceLifecycle: 'static',
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  release: '1.0',
+  tracesSampleRate: 1.0,
+  dataCollection: { genAI: { inputs: false, outputs: false } },
+  integrations: [Sentry.mastraIntegration({ bootstrapObservability: false })],
+  transport: loggingTransport,
+  beforeSendTransaction: event => {
+    // Drop the in-process mock provider's own transactions.
+    return event.transaction?.includes('/v1/chat/completions') ? null : event;
+  },
+});
@@ -0,0 +1,15 @@
+import * as Sentry from '@sentry/node';
+import { loggingTransport } from '@sentry-internal/node-integration-tests';
+
+Sentry.init({
+  traceLifecycle: 'static',
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  release: '1.0',
+  tracesSampleRate: 1.0,
+  dataCollection: { genAI: { inputs: true, outputs: true } },
+  transport: loggingTransport,
+  beforeSendTransaction: event => {
+    // Drop the in-process mock provider's own transactions.
+    return event.transaction?.includes('/v1/chat/completions') ? null : event;
+  },
+});
@@ -0,0 +1,15 @@
+import * as Sentry from '@sentry/node';
+import { loggingTransport } from '@sentry-internal/node-integration-tests';
+
+Sentry.init({
+  traceLifecycle: 'static',
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  release: '1.0',
+  tracesSampleRate: 1.0,
+  dataCollection: { genAI: { inputs: false, outputs: false } },
+  transport: loggingTransport,
+  beforeSendTransaction: event => {
+    // Drop the in-process mock provider's own transactions.
+    return event.transaction?.includes('/v1/chat/completions') ? null : event;
+  },
+});
@@ -0,0 +1,71 @@
+import express from 'express';
+import * as Sentry from '@sentry/node';
+import { Mastra } from '@mastra/core';
+import { Agent } from '@mastra/core/agent';
+
+// Inlined OpenAI-compatible mock: the ESM/CJS runner copies only this file into its temp dir.
+function startMockProvider(responses) {
+  const app = express();
+  app.use(express.json());
+
+  let call = 0;
+  app.post('/v1/chat/completions', (req, res) => {
+    const response = responses[Math.min(call, responses.length - 1)];
+    call++;
+    res.json({
+      id: response.id,
+      object: 'chat.completion',
+      created: 1,
+      model: req.body.model,
+      choices: [
+        {
+          index: 0,
+          finish_reason: response.toolCalls ? 'tool_calls' : 'stop',
+          message: {
+            role: 'assistant',
+            content: response.content ?? null,
+            ...(response.toolCalls ? { tool_calls: response.toolCalls } : {}),
+          },
+        },
+      ],
+      usage: response.usage,
+    });
+  });
+
+  const server = app.listen(0);
+  return {
+    url: `http://localhost:${server.address().port}/v1`,
+    close: () => server.close(),
+  };
+}
+
+const provider = startMockProvider([
+  {
+    id: 'chatcmpl-1',
+    content: 'It is 22C in Berlin.',
+    usage: { prompt_tokens: 12, completion_tokens: 7, total_tokens: 19 },
+  },
+]);
+
+async function run() {
+  const agent = new Agent({
+    id: 'weather_agent',
+    name: 'weather_agent',
+    instructions: 'You report the weather.',
+    model: { id: 'openai/gpt-4o-mini', url: provider.url, apiKey: 'test' },
+  });
+
+  const mastra = new Mastra({
+    agents: { weather_agent: agent },
+    logger: false,
+  });
+
+  await Sentry.startSpan({ op: 'function', name: 'mastra-test' }, async () => {
+    await mastra.getAgent('weather_agent').generate('What is the weather in Berlin?');
+  });
+
+  await mastra.observability.shutdown();
+  provider.close();
+}
+
+run();
@@ -0,0 +1,85 @@
+import express from 'express';
+import * as Sentry from '@sentry/node';
+import { Mastra } from '@mastra/core';
+import { Agent } from '@mastra/core/agent';
+import { Observability } from '@mastra/observability';
+
+// Inlined OpenAI-compatible mock: the ESM/CJS runner copies only this file into its temp dir.
+function startMockProvider(responses) {
+  const app = express();
+  app.use(express.json());
+
+  let call = 0;
+  app.post('/v1/chat/completions', (req, res) => {
+    const response = responses[Math.min(call, responses.length - 1)];
+    call++;
+    res.json({
+      id: response.id,
+      object: 'chat.completion',
+      created: 1,
+      model: req.body.model,
+      choices: [
+        {
+          index: 0,
+          finish_reason: response.toolCalls ? 'tool_calls' : 'stop',
+          message: {
+            role: 'assistant',
+            content: response.content ?? null,
+            ...(response.toolCalls ? { tool_calls: response.toolCalls } : {}),
+          },
+        },
+      ],
+      usage: response.usage,
+    });
+  });
+
+  const server = app.listen(0);
+  return {
+    url: `http://localhost:${server.address().port}/v1`,
+    close: () => server.close(),
+  };
+}
+
+const provider = startMockProvider([
+  {
+    id: 'chatcmpl-1',
+    content: 'It is 22C in Berlin.',
+    usage: { prompt_tokens: 12, completion_tokens: 7, total_tokens: 19 },
+  },
+]);
+
+async function run() {
+  // Stub of `@mastra/sentry`: same `name: 'sentry'`, no brand. The real package calls `Sentry.init()`.
+  const communityExporter = {
+    name: 'sentry',
+    async exportTracingEvent() {},
+    async flush() {},
+    async shutdown() {},
+  };
+
+  const agent = new Agent({
+    id: 'weather_agent',
+    name: 'weather_agent',
+    instructions: 'You report the weather.',
+    model: { id: 'openai/gpt-4o-mini', url: provider.url, apiKey: 'test' },
+  });
+
+  const mastra = new Mastra({
+    agents: { weather_agent: agent },
+    logger: false,
+    observability: new Observability({
+      configs: {
+        default: { serviceName: 'mastra-test', exporters: [communityExporter] },
+      },
+    }),
+  });
+
+  await Sentry.startSpan({ op: 'function', name: 'mastra-test' }, async () => {
+    await mastra.getAgent('weather_agent').generate('What is the weather in Berlin?');
+  });
+
+  await mastra.observability.shutdown();
+  provider.close();
+}
+
+run();
@@ -0,0 +1,102 @@
+import express from 'express';
+import * as Sentry from '@sentry/node';
+import { z } from 'zod';
+import { Mastra } from '@mastra/core';
+import { Agent } from '@mastra/core/agent';
+import { createTool } from '@mastra/core/tools';
+import { Observability } from '@mastra/observability';
+import { SentryMastraExporter } from '@sentry/node';
+
+// Two-step agent loop. Inlined OpenAI-compatible mock: the ESM/CJS runner copies only this file.
+function startMockProvider(responses) {
+  const app = express();
+  app.use(express.json());
+
+  let call = 0;
+  app.post('/v1/chat/completions', (req, res) => {
+    const response = responses[Math.min(call, responses.length - 1)];
+    call++;
+    res.json({
+      id: response.id,
+      object: 'chat.completion',
+      created: 1,
+      model: req.body.model,
+      choices: [
+        {
+          index: 0,
+          finish_reason: response.toolCalls ? 'tool_calls' : 'stop',
+          message: {
+            role: 'assistant',
+            content: response.content ?? null,
+            ...(response.toolCalls ? { tool_calls: response.toolCalls } : {}),
+          },
+        },
+      ],
+      usage: response.usage,
+    });
+  });
+
+  const server = app.listen(0);
+  return {
+    url: `http://localhost:${server.address().port}/v1`,
+    close: () => server.close(),
+  };
+}
+
+const provider = startMockProvider([
+  {
+    id: 'chatcmpl-tool',
+    toolCalls: [
+      {
+        id: 'call_1',
+        type: 'function',
+        function: { name: 'get_weather', arguments: '{"city":"Berlin"}' },
+      },
+    ],
+    usage: { prompt_tokens: 20, completion_tokens: 5, total_tokens: 25 },
+  },
+  {
+    id: 'chatcmpl-final',
+    content: 'It is 22C in Berlin.',
+    usage: { prompt_tokens: 30, completion_tokens: 8, total_tokens: 38 },
+  },
+]);
+
+async function run() {
+  const agent = new Agent({
+    id: 'weather_agent',
+    name: 'weather_agent',
+    instructions: 'Use the weather tool.',
+    model: { id: 'openai/gpt-4o-mini', url: provider.url, apiKey: 'test' },
+    tools: {
+      get_weather: createTool({
+        id: 'get_weather',
+        description: 'Get weather for a city',
+        inputSchema: z.object({ city: z.string() }),
+        execute: async ({ city }) => ({ temperature: 22, city }),
+      }),
+    },
+  });
+
+  const mastra = new Mastra({
+    agents: { weather_agent: agent },
+    logger: false,
+    observability: new Observability({
+      configs: {
+        default: {
+          serviceName: 'mastra-test',
+          exporters: [new SentryMastraExporter()],
+        },
+      },
+    }),
+  });
+
+  await Sentry.startSpan({ op: 'function', name: 'mastra-test' }, async () => {
+    await mastra.getAgent('weather_agent').generate('Weather in Berlin?', { maxSteps: 3 });
+  });
+
+  await mastra.observability.shutdown();
+  provider.close();
+}
+
+run();
@@ -0,0 +1,46 @@
+import * as Sentry from '@sentry/node';
+import { z } from 'zod';
+import { Mastra } from '@mastra/core';
+import { createStep, createWorkflow } from '@mastra/core/workflows';
+import { Observability } from '@mastra/observability';
+import { SentryMastraExporter } from '@sentry/node';
+
+// `workflow_run` maps to `gen_ai.invoke_agent`; `workflow_step` has no conventional op and is dropped.
+const double = createStep({
+  id: 'double',
+  inputSchema: z.object({ n: z.number() }),
+  outputSchema: z.object({ n: z.number() }),
+  execute: async ({ inputData }) => ({ n: inputData.n * 2 }),
+});
+
+const workflow = createWorkflow({
+  id: 'math_workflow',
+  inputSchema: z.object({ n: z.number() }),
+  outputSchema: z.object({ n: z.number() }),
+})
+  .then(double)
+  .commit();
+
+async function run() {
+  const mastra = new Mastra({
+    workflows: { math_workflow: workflow },
+    logger: false,
+    observability: new Observability({
+      configs: {
+        default: {
+          serviceName: 'mastra-test',
+          exporters: [new SentryMastraExporter()],
+        },
+      },
+    }),
+  });
+
+  await Sentry.startSpan({ op: 'function', name: 'mastra-test' }, async () => {
+    const workflowRun = await mastra.getWorkflow('math_workflow').createRun();
+    await workflowRun.start({ inputData: { n: 21 } });
+  });
+
+  await mastra.observability.shutdown();
+}
+
+run();