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:

  dsn: "",
  maxBreadcrumbs: 50,
  debug: true,

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.


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.


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.


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.


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).


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.


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.


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.


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.


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.


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


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.


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.


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.


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

frameContextLines has moved to the ContextLines integration.


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


  dsn: "",
  debug: true,
  initialScope: {
    tags: { "my-tag": "my value" },
    user: { id: 42, email: "" },

Callback function:

  dsn: "",
  debug: true,
  initialScope: (scope) => {
    scope.setTags({ a: "b" });
    return scope;


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


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.


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)


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.


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.


Set this boolean to true to add stack local variables to stack traces.

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.


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


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

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


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.


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.


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.

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


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.


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.
  • proxy: A proxy used for outbound requests. Can be http or https.
  • caCerts: A path or list of paths to a CA certificate, or a buffer of CA certificates.
  • httpModule: A custom HTTP module to use for requests. Defaults to the the native http and https modules.
  • keepAlive: Determines whether to keep the socket alive between requests. Defaults to false.


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.


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.


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.


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.


An optional property that controls which downstream services receive tracing data, in the form of a sentry-trace and a baggage header attached to any outgoing HTTP requests.

The option may contain a list of strings or regex against which the URLs of outgoing requests are matched. If one of the entries in the list matches the URL of an outgoing request, trace data will be attached to that request. String entries do not have to be full matches, meaning the URL of a request is matched when it contains a string provided through the option.

If tracePropagationTargets is not provided, trace data is attached to every outgoing request from the instrumented client.

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