Basic Options

SDKs are configurable using a variety of options. The options are largely standardized among SDKs, but there are some differences to better accommodate platform peculiarities. Options are set when the SDK is first initialized.

Sentry.init({
  dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
  maxBreadcrumbs: 50,
  debug: true,
});

Common Options

The list of common options across SDKs. These work more or less the same in all SDKs, but some subtle differences will exist to better support the platform. Options that can be read from an environment variable (SENTRY_DSN, SENTRY_ENVIRONMENT, SENTRY_RELEASE) are read automatically.

dsn

The DSN tells the SDK where to send the events. If this value is not provided, the SDK will try to read it from the SENTRY_DSN environment variable. If that variable also does not exist, the SDK will just not send any events.

In runtimes without a process environment (such as the browser) that fallback does not apply.

Learn more about DSN utilization.

debug

Turns debug mode on or off. If debug is enabled SDK will attempt to print out useful debugging information if something goes wrong with sending the event. The default is always false. It's generally not recommended to turn it on in production, though turning debug mode on will not cause any safety concerns.

release

Sets the release. Some SDKs will try to automatically configure a release out of the box but it's a better idea to manually set it to guarantee that the release is in sync with your deploy integrations or source map uploads. Release names are strings, but some formats are detected by Sentry and might be rendered differently. Learn more about how to send release data so Sentry can tell you about regressions between releases and identify the potential source in the releases documentation or the sandbox.

By default the SDK will try to read this value from the SENTRY_RELEASE environment variable (in the browser SDK, this will be read off of the window.SENTRY_RELEASE if available).

environment

Sets the environment. This string is freeform and not set by default. A release can be associated with more than one environment to separate them in the UI (think staging vs prod or similar).

By default the SDK will try to read this value from the SENTRY_ENVIRONMENT environment variable (except for the browser SDK where this is not applicable).

tunnel

Sets the URL that will be used to transport captured events, instead of using the DSN. This can be used to work around ad-blockers or to have more granular control over events sent to Sentry. This option requires the implementation of a custom server endpoint. Learn more and find examples in Dealing with Ad-Blockers.

sampleRate

Configures the sample rate for error events, in the range of 0.0 to 1.0. The default is 1.0 which means that 100% of error events are sent. If set to 0.1 only 10% of error events will be sent. Events are picked randomly.

maxBreadcrumbs

This variable controls the total amount of breadcrumbs that should be captured. This defaults to 100.

attachStacktrace

When enabled, stack traces are automatically attached to all messages logged. Stack traces are always attached to exceptions; however, when this option is set, stack traces are also sent with messages. This option, for instance, means that stack traces appear next to all log messages.

This option is off by default.

Grouping in Sentry is different for events with stack traces and without. As a result, you will get new groups as you enable or disable this flag for certain events.

serverName

This option can be used to supply a "server name." When provided, the name of the server is sent along and persisted in the event. For many integrations the server name actually corresponds to the device hostname, even in situations where the machine is not actually a server. Most SDKs will attempt to auto-discover this value.

autoSessionTracking

When set to true, the SDK will send session events to Sentry. This is supported in all browser SDKs, emitting one session per pageload and page navigation to Sentry. In mobile SDKs, when the app goes to the background for longer than 30 seconds, sessions are ended.

caCerts

A path to an alternative CA bundle file in PEM-format.

frameContextLines

The number of context lines for each frame when loading a file.

initialScope

Data to be set to the initial scope. Initial scope can be defined either as an object or a callback function, as shown below.

Object:

Sentry.init({
  dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
  debug: true,
  initialScope: {
    tags: {"my-tag": "my value"},
    user: {id: 42, email: "john.doe@example.com"},
  }
});

Callback function:

Sentry.init({
  dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",
  debug: true,
  initialScope: scope => {
    scope.setTags({ a: 'b' });
    return scope;
  },
});

maxValueLength

Maximum number of characters a single value can have before it will be truncated (defaults to 250).

normalizeDepth

Sentry SDKs normalize any contextual data to a given depth. Any keys containing data with a structure deeper than this will be trimmed and marked using its type instead ([Object] or [Array]), without walking the tree any further. By default, walking is performed 3 levels deep.

Integration Configuration

For many platform SDKs integrations can be configured alongside it. On some platforms that happen as part of the init() call, in some others, different patterns apply.

integrations

In some SDKs, the integrations are configured through this parameter on library initialization. For more information, please see our documentation for a specific integration.

defaultIntegrations

This can be used to disable integrations that are added by default. When set to false, no default integrations are added.

Hooks

These options can be used to hook the SDK in various ways to customize the reporting of events.

beforeSend

This function is called with an SDK-specific event object, and can return a modified event object or nothing to skip reporting the event. This can be used, for instance, for manual PII stripping before sending.

beforeBreadcrumb

This function is called with an SDK-specific breadcrumb object before the breadcrumb is added to the scope. When nothing is returned from the function, the breadcrumb is dropped. To pass the breadcrumb through, return the first argument, which contains the breadcrumb object. The callback typically gets a second argument (called a "hint") which contains the original object from which the breadcrumb was created to further customize what the breadcrumb should look like.

Transport Options

Transports are used to send events to Sentry. Transports can be customized to some degree to better support highly specific deployments.

transport

Switches out the transport used to send events. How this works depends on the SDK. It can, for instance, be used to capture events for unit-testing or to send it through some more complex setup that requires proxy authentication.

httpProxy

When set, a proxy can be configured that should be used for outbound requests. This is also used for HTTPS requests unless a separate https-proxy is configured. However, not all SDKs support a separate HTTPS proxy. SDKs will attempt to default to the system-wide configured proxy, if possible. For instance, on Unix systems, the http_proxy environment variable will be picked up.

httpsProxy

Configures a separate proxy for outgoing HTTPS requests. This value might not be supported by all SDKs. When not supported the http-proxy value is also used for HTTPS requests at all times.

shutdownTimeout

Controls how many seconds to wait before shutting down. Sentry SDKs send events from a background queue. This queue is given a certain amount to drain pending events. The default is SDK specific but typically around two seconds. Setting this value too low may cause problems for sending events from command line applications. Setting the value too high will cause the application to block for a long time for users experiencing network connectivity problems.

Tracing Options

tracesSampleRate

A number between 0 and 1, controlling the percentage chance a given transaction will be sent to Sentry. (0 represents 0% while 1 represents 100%.) Applies equally to all transactions created in the app. Either this or tracesSampler must be defined to enable tracing.

tracesSampler

A function responsible for determining the percentage chance a given transaction will be sent to Sentry. It will automatically be passed information about the transaction and the context in which it's being created, and must return a number between 0 (0% chance of being sent) and 1 (100% chance of being sent). Can also be used for filtering transactions, by returning 0 for those that are unwanted. Either this or tracesSampleRate must be defined to enable tracing.