Configuration reference

You can customize the Flare client using flare.configure(). Call it after flare.light():

import { flare } from '@flareapp/js';

flare.light('YOUR PROJECT KEY');

flare.configure({
    stage: 'production',
    maxGlowsPerReport: 50,
});

Options

General

Option	Default	Description
`stage`	`''`	Environment identifier (e.g. `'production'`, `'staging'`).
`version`	`''`	Application version string (e.g. `'2.1.0'`). Sent as `service.version` in reports.
`sourcemapVersionId`	`''`	Tells Flare which uploaded sourcemap resolves this build's stack traces. The Vite and Webpack plugins inject it at build time, so you only set it yourself when you upload sourcemaps another way.
`hasConsent`	`true`	When `false`, the client sends nothing: no errors, logs, or traces, and it drops anything buffered. Flip it at runtime with `setConsent()`. See GDPR consent.

Error reporting

Option	Default	Description
`maxGlowsPerReport`	`30`	Maximum number of glows (breadcrumbs) attached to each report.
`enableBreadcrumbs`	`false`	Opt in to automatic breadcrumbs. Flare records clicks, form changes, requests, and navigations while `true`. No breadcrumbs are recorded while `false`.
`maxBreadcrumbs`	`100`	Maximum number of breadcrumbs kept and attached to each report. When the limit is reached, the oldest breadcrumb is removed first.
`ingestUrl`	`https://ingress.flareapp.io/v1/errors`	Custom endpoint for error reports.
`reportBrowserExtensionErrors`	`false`	Whether to report errors caused by browser extensions. See reporting errors.
`debug`	`false`	Enable debug logging in the browser console.
`urlDenylist`	`DEFAULT_URL_DENYLIST`	A `RegExp` tested against query-string parameter names. Matching values are redacted from the `url.full` attribute and other URL-derived fields. Custom patterns are merged with the built-in denylist by default.
`replaceDefaultUrlDenylist`	`false`	When `true`, `urlDenylist` replaces the built-in denylist instead of extending it.
`sampleRate`	`1`	Number between `0` and `1` controlling what fraction of errors are reported. `0.5` means roughly 50% of errors are sent to Flare. Applies to `report()`, `reportMessage()`, and unhandled rejections.
`beforeEvaluate`	`(error) => error`	Hook called before an error is processed. Can be async. Returns the error unchanged by default. See client hooks.
`beforeSubmit`	`(report) => report`	Hook called before a report is sent. Can be async. Returns the report unchanged by default. See client hooks.

Logging

Option	Default	Description
`enableLogs`	`false`	Opt in to structured logging. No logs are recorded or sent while `false`.
`minimumLogLevel`		Drop logs below this severity. When unset, all levels are sent.
`serviceName`		Service name attached to log records (sent as `service.name`).
`maxLogBufferSize`	`100`	Maximum number of buffered log records before a flush is triggered.
`logFlushIntervalMs`	`5000`	Milliseconds after the first buffered log before the batch is flushed.
`logFlushMaxBytes`	`800000`	Approximate buffered log payload size that triggers a flush.
`keepaliveMaxBytes`	`60000`	Byte budget for the unload (`keepalive`) log flush. Records that don't fit are dropped.
`logsIngestUrl`	`https://ingress.flareapp.io/v1/logs`	Custom endpoint for log batches.

Tracing

Option	Default	Description
`enableTracing`	`false`	Turn on tracing: page loads, navigations, `fetch`/`XMLHttpRequest` requests, and manual spans. No spans are recorded while `false`. See how tracing works.
`tracesSampleRate`	`1`	Number between `0` and `1` controlling what fraction of traces are sent. Values outside that range are clamped. Ignored when `tracesSampler` is set. See sampling.
`tracesSampler`		A function that decides sampling itself instead of using a fixed rate. Takes precedence over `tracesSampleRate` when set. See sampling.
`tracesIngestUrl`	`https://ingress.flareapp.io/v1/traces`	Custom endpoint for trace batches.
`idleTimeout`	`1000`	Milliseconds with no open child spans before a page load or navigation root span closes.
`finalTimeout`	`30000`	Milliseconds from a page load or navigation root's start before it closes regardless of activity. This is a hard upper limit that applies even when `idleTimeout` keeps resetting.
`childSpanTimeout`	`15000`	If a child span stays open this many milliseconds, its root closes anyway, even with other spans still open. This is a second limit that applies alongside `idleTimeout`.
`spanFlushIntervalMs`	`5000`	Milliseconds after the first buffered span before the batch is flushed.
`spanFlushMaxBytes`	`800000`	Approximate buffered span payload size that triggers a flush.
`maxSpanBufferSize`	`100`	Maximum number of buffered spans before a flush is triggered.
`maxSpansPerTrace`	`1024`	Maximum number of spans recorded for one trace. Once a trace reaches this limit, further spans started in it are not recorded. See how component profiling works for a case where this matters.
`maxAttributesPerSpan`	`128`	Maximum number of attributes kept on one span. Further attributes are dropped.
`maxEventsPerSpan`	`128`	Maximum number of events kept on one span. Further events are dropped.
`maxAttributesPerSpanEvent`	`128`	Maximum number of attributes kept on one span event. Further attributes are dropped.

Customizing the URL denylist

The default urlDenylist redacts query-string values for the following sensitive parameter names: password, passwd, pwd, token, secret, authorization, auth, bearer, oauth, credentials, cookie, api_key, private_key, session, csrf, xsrf, pin, ssn, card_number, and cvv. Path and hash segments are left untouched.

A custom urlDenylist is merged with the built-in denylist by default, so you won't accidentally lose redaction for sensitive terms like password or token:

flare.configure({
    urlDenylist: /myCustomParam|internalId/i,
});

If the built-in denylist matches too aggressively for your use case, you can replace it entirely:

flare.configure({
    urlDenylist: /onlyThisParam/i,
    replaceDefaultUrlDenylist: true,
});

API

On this page

Options