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.

Options are passed to the init() function as object:

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 window.SENTRY_RELEASE.id 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. This can be used to work around ad-blockers or to have more granular control over events sent to Sentry. Adding your DSN is still required when using this option so necessary attributes can be set on the generated Sentry data. 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 will be 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, but you can set this to any number. However, you should be aware that Sentry has a maximum payload size and any events exceeding that payload size will be dropped.

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 turned 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.

ignoreErrors

A list of strings or regex patterns that match error messages that shouldn't be sent to Sentry. Messages that match these strings or regular expressions will be filtered out before they're sent to Sentry. When using strings, partial matches will be filtered out, so if you need to filter by exact match, use regex patterns instead. By default, all errors are sent.

ignoreTransactions

A list of strings or regex patterns that match transaction names that shouldn't be sent to Sentry. Transactions that match these strings or regular expressions will be filtered out before they're sent to Sentry. When using strings, partial matches will be filtered out, so if you need to filter by exact match, use regex patterns instead. By default, transactions spanning typical API health check requests are filtered out.

denyUrls

An array of strings or regex patterns that match the URLs of scripts where errors have been created. Errors that have been created on these URLs won't be sent to Sentry. If you use this option, errors will not be sent when the top stack frame file URL contains or matches at least one entry in the denyUrls array. All string entries in the array will be matched with stackFrameUrl.contains(entry), while all RegEx entries will be matched with stackFrameUrl.match(entry).

This matching logic applies to captured exceptions not raw message events. By default, all errors are sent.

allowUrls

An array of strings or regex patterns that match the URLs of scripts where errors have been created. Only errors that have been created on these URLs will be sent to Sentry. If you use this option, errors will only be sent when the top stack frame file URL contains or matches at least one entry in the allowUrls array. All string entries in the array will be matched with stackFrameUrl.contains(entry), while all RegEx entries will be matched with stackFrameUrl.match(entry).

For example, if you add 'foo.com' to the array, errors created on https://bar.com/myfile/foo.com will be captured because URL will be matched with "contains" logic and the last segment of the URL contains foo.com.

This matching logic applies for captured exceptions, not raw message events. By default, all errors are sent.

If your scripts are loaded from cdn.example.com and your site is example.com, you can set allowUrls to the follwing to exclusively capture errors being created in scripts in these locations:

Sentry.init({
  allowUrls: [/https?:\/\/((cdn|www)\.)?example\.com/],
});

autoSessionTracking

Defaults to true. 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.

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 data beyond this depth will be trimmed and marked using its type instead ([Object] or [Array]), without walking the tree any further. By default, walking is performed three levels deep.

normalizeMaxBreadth

This is the maximum number of properties or entries that will be included in any given object or array when the SDK is normalizing contextual data. Any data beyond this depth will be dropped. (defaults to 1000)

enabled

Specifies whether this SDK should send events to Sentry. Defaults to true. Setting this to enabled: false doesn't prevent all overhead from Sentry instrumentation. To disable Sentry completely, depending on environment, call Sentry.init conditionally.

sendClientReports

Set this boolean to false to disable sending of client reports. Client reports are a protocol feature that let clients send status reports about themselves to Sentry. They are currently mainly used to emit outcomes for events that were never sent.

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 message or error event object, and can return a modified event object, or null to skip reporting the event. This can be used, for instance, for manual PII stripping before sending.

By the time beforeSend is executed, all scope data has already been applied to the event. Further modification of the scope won't have any effect.

beforeSendTransaction

This function is called with an SDK-specific transaction event object, and can return a modified transaction event object, or null to skip reporting the event. One way this might be used is for manual PII stripping before sending.

beforeSendSpan

This function is called with a serialized span object, and can return a modified span object, or null to skip sending the span. This might be useful for manually stripping PII from spans or to remove individual spans from the span tree. This function is only called for child spans of the root span. If you want to modify or drop the root span, including all of its child spans, use beforeSendTransaction instead.

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.

transportOptions

Options used to configure the transport. This is an object with the following possible optional keys:

• headers: An object containing headers to be sent with every request. Used by the SDK's fetch and XHR transports.
• fetchOptions: An object containing options to be passed to the fetch call. Used by the SDK's fetch transport.

Tracing Options

enableTracing

A boolean value, if true, transactions and trace data will be generated and captured. This will set the traces-sample-rate to the recommended default of 1.0 if traces-sample-rate is not defined. Note that traces-sample-rate and traces-sampler take precedence over this option.

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.