---
title: "File I/O"
description: "Learn more about the Sentry file I/O integration for the Dart SDK."
url: https://docs.sentry.io/platforms/dart/integrations/file/
---

# File I/O | Sentry for Dart

File I/O operations are fundamental for reading from and writing to files within an application. The `sentry_file` integration provides [File](https://api.dart.dev/stable/2.18.5/dart-io/File-class.html) support for Sentry thus providing insight into tracing of file operations.

## [Behavior](https://docs.sentry.io/platforms/dart/integrations/file.md#behavior)

* The created spans will be attached to the transaction on the scope - if no transaction is on the scope the File I/O span will not be sent to Sentry.
* The File I/O integration is only available for the `dart:io:File` class, not for the `dart:html:File` class.
* The SDK sets the span `operation` to `file.copy`, `file.write`, `file.delete`, `file.open`, `file.read` or `file.rename`, and `description` to `filename` (for example, `file.txt`).
* The span finishes once the operation has been executed. The span `status` is then set to `SpanStatus.ok` if successful, or `SpanStatus.internalError` if there was an error.
* When the operation throws an `Exception`, Sentry's SDK associates it with the running span.

## [Prerequisites](https://docs.sentry.io/platforms/dart/integrations/file.md#prerequisites)

1. The Sentry [Dart](https://docs.sentry.io/platforms/dart.md#configure) SDK is initialized.
2. Tracing is set up. Learn more [here](https://docs.sentry.io/platforms/dart/tracing.md).

## [Install](https://docs.sentry.io/platforms/dart/integrations/file.md#install)

To use the `SentryFile` wrapper, add the `sentry_file` dependency.

`pubspec.yaml`

```yml
dependencies:
  sentry: ^9.16.1
  sentry_file: ^9.16.1
```

## [Configure](https://docs.sentry.io/platforms/dart/integrations/file.md#configure)

Call the Sentry extension method to wrap the file:

```dart
final sentryFile = file.sentryTrace();
```

## [Verify](https://docs.sentry.io/platforms/dart/integrations/file.md#verify)

### [1. Execute the Code](https://docs.sentry.io/platforms/dart/integrations/file.md#1-execute-the-code)

```dart
import 'package:sentry/sentry.dart';
import 'package:sentry_file/sentry_file.dart';
import 'dart:io';

Future<void> main() async {
  await Sentry.init(
    (options) {
      options.dsn = 'https://example@sentry.io/example';
      // To set a uniform sample rate
      options.tracesSampleRate = 1.0;
    },
    appRunner: runApp, // Init your App.
  );
}

Future<void> runApp() async {
  final file = File('my_file.txt');
  // Call the Sentry extension method to wrap up the File
  final sentryFile = file.sentryTrace();

  // Start a transaction if there's no active transaction
  final transaction = Sentry.startTransaction(
    'MyFileExample',
    'file',
    bindToScope: true,
  );

  // create the File
  await sentryFile.create();
  // Write some content
  await sentryFile.writeAsString('Hello World');
  // Read the content
  final text = await sentryFile.readAsString();

  print(text);

  // Delete the file
  await sentryFile.delete();

  // Finish the transaction
  await transaction.finish(status: SpanStatus.ok());

  await Sentry.close();
}
```

### [2. View the Recorded Transaction on Sentry.io](https://docs.sentry.io/platforms/dart/integrations/file.md#2-view-the-recorded-transaction-on-sentryio)

To view the recorded transaction, log into [sentry.io](https://sentry.io) and open your project. Clicking **Performance** will open a page with transactions, where you can select the just recorded transaction with the name `MyFileExample`.