Set Up Logs

# Logs

- Where logs are used, ensure Sentry is imported using `import * as Sentry from "@sentry/react"`
- Enable logging in Sentry using `Sentry.init({ enableLogs: true })`
- Sentry offers a `consoleLoggingIntegration` that can be used to log specific console error types automatically without instrumenting the individual logger calls

## Configuration

The Sentry initialization needs to be updated to enable the logs feature.

### Baseline

```javascript
Sentry.init({
  dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
  // Enable logs to be sent to Sentry
  enableLogs: true,
});
```

### Logger Integration

```javascript
Sentry.init({
  dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
  integrations: [
    // send console.log, console.error, and console.warn calls as logs to Sentry
    Sentry.consoleLoggingIntegration({ levels: ["log", "error", "warn"] }),
  ],
});
```

## Logger Examples

`Sentry.logger.fmt` is a template literal function that should be used to bring variables into the structured logs.

```javascript
import * as Sentry from "@sentry/react";

Sentry.logger.trace("Starting database connection", { database: "users" });
Sentry.logger.debug(Sentry.logger.fmt`Cache miss for user: ${userId}`);
Sentry.logger.info("Updated profile", { profileId: 345 });
Sentry.logger.warn("Rate limit reached for endpoint", {
  endpoint: "/api/results/",
  isEnterprise: false,
});
Sentry.logger.error("Failed to process payment", {
  orderId: "order_123",
  amount: 99.99,
});
Sentry.logger.fatal("Database connection pool exhausted", {
  database: "users",
  activeConnections: 100,
});
```

With Sentry Structured Logs, you can send text-based log information from your applications to Sentry. Once in Sentry, these logs can be viewed alongside relevant errors, searched by text-string, or searched using their individual attributes.

Requirements

Logs for JavaScript are supported in Sentry JavaScript SDK version 9.41.0 and above.

Setup

To enable logging, you need to initialize the SDK with the enableLogs option set to true.

Sentry.init({
  dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
  // Enable logs to be sent to Sentry
  enableLogs: true,
});

Usage

Once the feature is enabled on the SDK and the SDK is initialized, you can send logs using the Sentry.logger APIs.

The Sentry.logger namespace exposes six methods that you can use to log messages at different log levels: trace, debug, info, warn, error, and fatal.

Aside from the primary logging methods, we've provided a format text function, Sentry.logger.fmt, that you can use to insert properties into to your log entries.

These properties will be sent to Sentry, and can be searched from within the Logs UI, and even added to the Logs views as a dedicated column.

Sentry.logger.error(
  Sentry.logger.fmt`Uh on, something broke, here's the error: '${error}'`
);
Sentry.logger.info(
  Sentry.logger.fmt`'${user.username}' added '${product.name}' to cart.`
);

You can also pass additional attributes directly to the logging functions, avoiding the need to use the fmt function.

Sentry.logger.trace("Starting database connection", { database: "users" });
Sentry.logger.debug("Cache miss for user", { userId: 123 });
Sentry.logger.info("Updated profile", { profileId: 345 });
Sentry.logger.warn("Rate limit reached for endpoint", {
  endpoint: "/api/results/",
  isEnterprise: false,
});
Sentry.logger.error("Failed to process payment", {
  orderId: "order_123",
  amount: 99.99,
});
Sentry.logger.fatal("Database connection pool exhausted", {
  database: "users",
  activeConnections: 100,
});

Setting a log message is required for the Sentry SDK to send the log to Sentry.

Integrations

Console Logging Integration

You can also configure the SDK to send logs via the JavaScript console object, using the SDK's consoleLoggingIntegration.

Sentry.init({
  dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
  integrations: [
    // send console.log, console.warn, and console.error calls as logs to Sentry
    Sentry.consoleLoggingIntegration({ levels: ["log", "warn", "error"] }),
  ],
});

The consoleLoggingIntegration accepts a levels option, which is an array of console method names to log. By default the integration will log calls from console.debug, console.info, console.warn, console.error, console.log, console.assert, and console.trace.

Options

beforeSendLog

To filter logs, or update them before they are sent to Sentry, you can use the beforeSendLog option.

Sentry.init({
  dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
  enableLogs: true,
  beforeSendLog: (log) => {
    if (log.level === "info") {
      // Filter out all info logs
      return null;
    }

    return log;
  },
});

The beforeSendLog function receives a log object, and should return the log object if you want it to be sent to Sentry, or null if you want to discard it.

The log object has the following properties:

• level: (string - one of trace, debug, info, warn, error, fatal) The log level.
• message: (string) The message to be logged.
• timestamp: (number) The timestamp of the log.
• attributes: (object) The attributes of the log.

Default Attributes

The JavaScript SDK automatically sets several default attributes on all log entries to provide context and improve debugging:

Core Attributes

• environment: The environment set in the SDK if defined. This is sent from the SDK as sentry.environment.
• release: The release set in the SDK if defined. This is sent from the SDK as sentry.release.
• trace.parent_span_id: The span ID of the span that was active when the log was collected (only set if there was an active span). This is sent from the SDK as sentry.trace.parent_span_id.
• sdk.name: The name of the SDK that sent the log. This is sent from the SDK as sentry.sdk.name. This is sent from the SDK as sentry.sdk.name.
• sdk.version: The version of the SDK that sent the log. This is sent from the SDK as sentry.sdk.version. This is sent from the SDK as sentry.sdk.version.

Message Template Attributes

If the log was paramaterized, Sentry adds the message template and parameters as log attributes.

• message.template: The parameterized template string. This is sent from the SDK as sentry.message.template.
• message.parameter.X: The parameters to fill the template string. X can either be the number that represent the parameter's position in the template string (sentry.message.parameter.0, sentry.message.parameter.1, etc) or the parameter's name (sentry.message.parameter.item_id, sentry.message.parameter.user_id, etc). This is sent from the SDK as sentry.message.parameter.X.

For example, with the following log:

const user = "John";
const product = "Product 1";
Sentry.logger.info(
  Sentry.logger.fmt`'${user}' added '${product}' to cart.`,
);

Sentry will add the following attributes:

• message.template: "%s added %s to cart."
• message.parameter.0: "John"
• message.parameter.1: "Product 1"

Browser Attributes

• browser.name: Display name of the browser application.
• browser.version: Version string of the browser.

User Attributes

If user information is available in the current scope, the following attributes are added to the log:

• user.id: The user ID.
• user.name: The username.
• user.email: The email address.

Integration Attributes

If a log is generated by an SDK integration, the SDK will set additional attributes to help you identify the source of the log.

• origin: The origin of the log. This is sent from the SDK as sentry.origin.