[fastify 4] Request body is not captured with fastify integration

[tdournet]

Is there an existing issue for this?

• I have checked for existing issues https://github.com/getsentry/sentry-javascript/issues
• I have reviewed the documentation https://docs.sentry.io/
• I am using the latest SDK release https://github.com/getsentry/sentry-javascript/releases

How do you use Sentry?

Sentry Saas (sentry.io)

Which SDK are you using?

@sentry/node

SDK Version

9.11.0

Framework Version

fastify 4.28.0

Link to Sentry event

No response

Reproduction Example/SDK Setup

    Sentry.init({
      dsn: ...,
      tracesSampleRate: 0.1,
      release: process.env.RELEASE_NAME,
    });

    [...]

    this.fastifyServer = fastify();
    Sentry.setupFastifyErrorHandler(this.fastifyServer);

Steps to Reproduce

I installed sentry with fastify 4, following the documentation :

    Sentry.init({
      dsn: ...,
      tracesSampleRate: 0.1,
      release: process.env.RELEASE_NAME,
    });

    [...]

    this.fastifyServer = fastify();
    Sentry.setupFastifyErrorHandler(this.fastifyServer);

In every one of my sentry issues, I do not have a "body block" telling me the body payload of the incoming HTTP request. I have the request URL, the request headers, but no body payload.

Expected Result

Having the body payload in my issues in the incoming http requests informations, along with headers , and url (of couse, I tested for POST, PUT... in which I know I have a body with data in it)

Actual Result

[mydea]

Hey, are you running your app in esm or cjs mode? Did you make sure to follow the respective docs:

• CJS: https://docs.sentry.io/platforms/javascript/guides/fastify/install/commonjs/
• ESM: https://docs.sentry.io/platforms/javascript/guides/fastify/install/esm/

My best guess for this not working would be that instrumentation is not fully correct, then we may not be able to capture the request body. Could you enable debug: true in your init call and paste the logs you get, both on app startup as well as for an incoming request that should have body data?

[tdournet]

Hello, thanks for your answer.
I am running my app in cjs mode. Here is my init function :

Sentry.init({
    dsn,
    tracesSampleRate: tracesSampleRate ?? 0.1,
    release: process.env.RELEASE_NAME,
  });

This function is called before fastify is imported

I tried, as you said, to enable debug: true and here are my logs :

First, the logs for sentry initialization :

Sentry Logger [log]: Initializing Sentry: process: 18, thread: main.
Sentry Logger [log]: Integration installed: InboundFilters
Sentry Logger [log]: Integration installed: FunctionToString
Sentry Logger [log]: Integration installed: LinkedErrors
Sentry Logger [log]: Integration installed: RequestData
Sentry Logger [log]: Integration installed: Console
Sentry Logger [log]: Integration installed: Http
Sentry Logger [log]: Integration installed: NodeFetch
Sentry Logger [log]: Integration installed: OnUncaughtException
Sentry Logger [log]: Integration installed: OnUnhandledRejection
Sentry Logger [log]: Integration installed: ContextLines
Sentry Logger [log]: Integration installed: LocalVariablesAsync
Sentry Logger [log]: Integration installed: Context
Sentry Logger [log]: Integration installed: ChildProcess
Sentry Logger [log]: Integration installed: ProcessSession
Sentry Logger [log]: Integration installed: Modules
Sentry Logger [log]: Integration installed: Express
Sentry Logger [log]: Integration installed: Fastify
Sentry Logger [log]: Integration installed: Graphql
Sentry Logger [log]: Integration installed: Mongo
Sentry Logger [log]: Integration installed: Mongoose
Sentry Logger [log]: Integration installed: Mysql
Sentry Logger [log]: Integration installed: Mysql2
Sentry Logger [log]: Integration installed: Redis
Sentry Logger [log]: Integration installed: Postgres
Sentry Logger [log]: Integration installed: Hapi
Sentry Logger [log]: Integration installed: Koa
Sentry Logger [log]: Integration installed: Connect
Sentry Logger [log]: Integration installed: Tedious
Sentry Logger [log]: Integration installed: GenericPool
Sentry Logger [log]: Integration installed: Kafka
Sentry Logger [log]: Integration installed: Amqplib
Sentry Logger [log]: Integration installed: LruMemoizer
Sentry Logger [log]: Integration installed: VercelAI
Sentry Logger [log]: Running in CommonJS mode.
Sentry Logger [debug]: @opentelemetry/api: Registered a global for diag v1.9.0.
Sentry Logger [debug]: @opentelemetry/api: Registered a global for trace v1.9.0.
Sentry Logger [debug]: @opentelemetry/api: Registered a global for propagation v1.9.0.
Sentry Logger [debug]: @opentelemetry/api: Registered a global for context v1.9.0.
Sentry Logger [debug]: @opentelemetry/instrumentation-kafkajs Applying instrumentation patch for module on require hook {
  module: 'kafkajs',
  version: '2.2.4',
  baseDir: '/app/node_modules/kafkajs'
}
Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http Applying instrumentation patch for nodejs core module on require hook { module: 'http' }
Sentry Logger [debug]: @sentry/instrumentation-http Applying instrumentation patch for nodejs core module on require hook { module: 'http' }
Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http Applying instrumentation patch for nodejs core module on require hook { module: 'https' }
Sentry Logger [debug]: @sentry/instrumentation-http Applying instrumentation patch for nodejs core module on require hook { module: 'https' }
Sentry Logger [debug]: @opentelemetry/instrumentation-fastify Applying instrumentation patch for module on require hook {
  module: 'fastify',
  version: '4.28.0',
  baseDir: '/app/node_modules/fastify'
}
Sentry Logger [debug]: @opentelemetry/instrumentation-pg Applying instrumentation patch for nodejs module file on require hook {
  module: 'pg',
  version: '8.12.0',
  fileName: 'pg/lib/client.js',
  baseDir: '/app/node_modules/pg'
}
Sentry Logger [debug]: @opentelemetry/instrumentation-pg Patching pg.Client.prototype.query
Sentry Logger [debug]: @opentelemetry/instrumentation-pg Applying instrumentation patch for module on require hook {
  module: 'pg-pool',
  version: '3.6.2',
  baseDir: '/app/node_modules/pg-pool'
}
Sentry Logger [debug]: @opentelemetry/instrumentation-pg Applying instrumentation patch for module on require hook { module: 'pg', version: '8.12.0', baseDir: '/app/node_modules/pg' }
Sentry Logger [debug]: @opentelemetry/instrumentation-pg Patching pg.Client.prototype.query
Sentry Logger [debug]: @opentelemetry/instrumentation-fastify Patching fastify preHandler function
Sentry Logger [debug]: @opentelemetry/instrumentation-fastify Patching fastify server.addHook function
Sentry Logger [debug]: @opentelemetry/instrumentation-fastify Patching fastify route.handler function
Sentry Logger [debug]: @opentelemetry/instrumentation-fastify Patching fastify route.handler function
Sentry Logger [debug]: @opentelemetry/instrumentation-fastify Patching fastify route.handler function
Sentry Logger [debug]: @opentelemetry/instrumentation-fastify Patching fastify route.handler function
Sentry Logger [debug]: @opentelemetry/instrumentation-fastify Patching fastify route.handler function
Sentry Logger [debug]: @sentry/instrumentation-http http instrumentation for outgoing requests
Sentry Logger [debug]: Recording is off, propagating context in a non-recording span
Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http http instrumentation outgoingRequest
Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http http.ClientRequest return request
Sentry Logger [debug]: @sentry/instrumentation-http http instrumentation for outgoing requests
Sentry Logger [debug]: Recording is off, propagating context in a non-recording span

and then the logs for an endpoint on which I don't see the body of my request.

2025-04-18T13:49:23.821+02:00Sentry Logger [debug]: Recording is off, propagating context in a non-recording span
2025-04-18T13:49:23.821+02:00Sentry Logger [log]: [Tracing] Inheriting parent's sampled decision for pg.query:SELECT crm: false
2025-04-18T13:49:23.821+02:00Sentry Logger [debug]: Recording is off, propagating context in a non-recording span
2025-04-18T13:49:23.822+02:00Sentry Logger [log]: [Tracing] Inheriting parent's sampled decision for pg.query:SELECT crm: false
2025-04-18T13:49:23.822+02:00Sentry Logger [debug]: Recording is off, propagating context in a non-recording span
2025-04-18T13:49:25.461+02:00Sentry Logger [debug]: @sentry/instrumentation-http http instrumentation for outgoing requests
2025-04-18T13:49:25.461+02:00Sentry Logger [debug]: Recording is off, propagating context in a non-recording span
2025-04-18T13:49:25.461+02:00Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http https instrumentation outgoingRequest
2025-04-18T13:49:25.461+02:00Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http http.ClientRequest return request
2025-04-18T13:49:25.477+02:00Sentry Logger [debug]: @sentry/instrumentation-http http instrumentation for outgoing requests
2025-04-18T13:49:25.478+02:00Sentry Logger [debug]: Recording is off, propagating context in a non-recording span
2025-04-18T13:49:25.480+02:00Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http https instrumentation outgoingRequest
2025-04-18T13:49:25.480+02:00Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http http.ClientRequest return request
2025-04-18T13:49:25.481+02:00Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http outgoingRequest on response()
2025-04-18T13:49:25.481+02:00Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http outgoingRequest on end()
2025-04-18T13:49:25.481+02:00Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http outgoingRequest on request close()
2025-04-18T13:49:25.506+02:00Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http outgoingRequest on response()
2025-04-18T13:49:25.507+02:00Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http outgoingRequest on end()
2025-04-18T13:49:25.507+02:00Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http outgoingRequest on request close()
2025-04-18T13:49:25.716+02:00Sentry Logger [log]: Flushing client reports based on interval.
2025-04-18T13:49:25.716+02:00Sentry Logger [log]: Flushing outcomes...
2025-04-18T13:49:25.716+02:00Sentry Logger [log]: Sending outcomes: [ { reason: 'sample_rate', category: 'transaction', quantity: 42 } ]
2025-04-18T13:49:25.716+02:00Sentry Logger [debug]: @sentry/instrumentation-http http instrumentation for outgoing requests
2025-04-18T13:49:25.717+02:00Sentry Logger [debug]: Instrumentation suppressed, returning Noop Span
2025-04-18T13:49:25.717+02:00Sentry Logger [log]: [Tracing] Not injecting trace data for url because tracing is suppressed.
2025-04-18T13:49:25.720+02:00Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http https instrumentation outgoingRequest
2025-04-18T13:49:25.720+02:00Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http http.ClientRequest return request
2025-04-18T13:49:25.753+02:00Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http outgoingRequest on response()
2025-04-18T13:49:25.753+02:00Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http outgoingRequest on end()
2025-04-18T13:49:25.753+02:00Sentry Logger [debug]: @opentelemetry_sentry-patched/instrumentation-http outgoingRequest on request close()

Still can't see any body :

[mydea]

Are you consuming the body yourself in your application? We capture request bodiues by patching request.on('data'), but we only do that if this is also listened to by the application. Can you share the code of the endpoint (simplified, if necessary) that should have the body captured?