Add errorFingerprinting config option to disable fingerprinting in browser

Minified browser code produces unstable fingerprints because function
names are mangled, causing the same logical error to generate different
fingerprints across deployments.

- Add errorFingerprinting option to LogfireApiConfigOptions
- Browser SDK defaults to false, Node SDK defaults to true
- Conditionally compute fingerprint in reportError() based on setting

Author: petyosi

.changeset/add-error-fingerprinting-config.md

@@ -0,0 +1,14 @@
+---
+"logfire": minor
+"@pydantic/logfire-browser": minor
+"@pydantic/logfire-node": minor
+---
+
+Add `errorFingerprinting` configuration option to control error fingerprint computation
+
+Error fingerprinting enables grouping similar errors in the Logfire backend. However, minified browser code produces unstable fingerprints because function names are mangled, causing the same logical error to generate different fingerprints across deployments.
+
+- Added `errorFingerprinting` option to `LogfireApiConfigOptions`
+- Browser SDK now defaults to `errorFingerprinting: false`
+- Node SDK keeps the default `errorFingerprinting: true`
+- Users can override the default in either SDK via the `configure()` options

packages/logfire-api/src/index.ts

@@ -191,24 +191,21 @@ export function warning(message: string, attributes: Record<string, unknown> = {
 /**
  * Use this method to report an error to Logfire.
  * Captures the error stack trace and message in the respective semantic attributes and sets the correct level and status.
- * Computes a fingerprint for the error to enable issue grouping in the Logfire backend.
+ * Computes a fingerprint for the error to enable issue grouping in the Logfire backend (if errorFingerprinting is enabled).
  */
 export function reportError(message: string, error: Error, extraAttributes: Record<string, unknown> = {}) {
-  const fingerprint = computeFingerprint(error)
+  const attributes: Record<string, unknown> = {
+    // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
+    [ATTR_EXCEPTION_MESSAGE]: error.message ?? 'error',
+    [ATTR_EXCEPTION_STACKTRACE]: error.stack,
+    ...extraAttributes,
+  }
 
-  const span = startSpan(
-    message,
-    {
-      // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
-      [ATTR_EXCEPTION_MESSAGE]: error.message ?? 'error',
-      [ATTR_EXCEPTION_STACKTRACE]: error.stack,
-      [ATTRIBUTES_EXCEPTION_FINGERPRINT_KEY]: fingerprint,
-      ...extraAttributes,
-    },
-    {
-      level: Level.Error,
-    }
-  )
+  if (logfireApiConfig.enableErrorFingerprinting) {
+    attributes[ATTRIBUTES_EXCEPTION_FINGERPRINT_KEY] = computeFingerprint(error)
+  }
+
+  const span = startSpan(message, attributes, { level: Level.Error })
 
   span.recordException(error)
   span.setStatus({ code: SpanStatusCode.ERROR, message: `${error.name}: ${error.message}` })

packages/logfire-api/src/logfireApiConfig.ts

@@ -13,6 +13,12 @@ export interface ScrubbingOptions {
 }
 
 export interface LogfireApiConfigOptions {
+  /**
+   * Whether to compute fingerprints for errors reported via reportError().
+   * Fingerprints enable error grouping in the Logfire backend.
+   * Defaults to true for Node.js, false for browser (minified code produces unstable fingerprints).
+   */
+  errorFingerprinting?: boolean
   otelScope?: string
   /**
    * Options for scrubbing sensitive data. Set to False to disable.
@@ -44,6 +50,7 @@ export interface LogOptions {
 
 export interface LogfireApiConfig {
   context: Context
+  enableErrorFingerprinting: boolean
   otelScope: string
   scrubber: BaseScrubber
   tracer: Tracer
@@ -58,6 +65,7 @@ const DEFAULT_LOGFIRE_API_CONFIG: LogfireApiConfig = {
   get context() {
     return ContextAPI.active()
   },
+  enableErrorFingerprinting: true,
   otelScope: DEFAULT_OTEL_SCOPE,
   scrubber: new LogfireAttributeScrubber(),
   tracer: TraceAPI.getTracer(DEFAULT_OTEL_SCOPE),
@@ -66,6 +74,10 @@ const DEFAULT_LOGFIRE_API_CONFIG: LogfireApiConfig = {
 export const logfireApiConfig: LogfireApiConfig = DEFAULT_LOGFIRE_API_CONFIG
 
 export function configureLogfireApi(config: LogfireApiConfigOptions) {
+  if (config.errorFingerprinting !== undefined) {
+    logfireApiConfig.enableErrorFingerprinting = config.errorFingerprinting
+  }
+
   if (config.scrubbing !== undefined) {
     logfireApiConfig.scrubber = resolveScrubber(config.scrubbing)
   }

packages/logfire-browser/src/index.ts

@@ -74,6 +74,11 @@ export interface LogfireConfigOptions {
    * Defaults to the `LOGFIRE_ENVIRONMENT` environment variable.
    */
   environment?: string
+  /**
+   * Whether to compute fingerprints for errors reported via reportError().
+   * Defaults to false for browser since minified code produces unstable fingerprints.
+   */
+  errorFingerprinting?: boolean
   /**
    * The instrumentations to register - a common one [is the fetch instrumentation](https://www.npmjs.com/package/@opentelemetry/instrumentation-fetch).
    */
@@ -119,9 +124,10 @@ export function configure(options: LogfireConfigOptions) {
     diag.setLogger(new DiagConsoleLogger(), options.diagLogLevel)
   }
 
-  if (options.scrubbing !== undefined) {
-    configureLogfireApi({ scrubbing: options.scrubbing })
-  }
+  configureLogfireApi({
+    errorFingerprinting: options.errorFingerprinting ?? false,
+    scrubbing: options.scrubbing,
+  })
 
   const resource = resourceFromAttributes({
     [ATTR_BROWSER_LANGUAGE]: navigator.language,

packages/logfire-node/src/logfireConfig.ts

@@ -69,6 +69,12 @@ export interface LogfireConfigOptions {
    * Defaults to the `LOGFIRE_ENVIRONMENT` environment variable.
    */
   environment?: string
+  /**
+   * Whether to compute fingerprints for errors reported via reportError().
+   * Fingerprints enable error grouping in the Logfire backend.
+   * Defaults to true for Node.js.
+   */
+  errorFingerprinting?: boolean
   /**
    * Additional third-party instrumentations to use.
    */
@@ -169,12 +175,12 @@ const DEFAULT_LOGFIRE_CONFIG: LogfireConfig = {
 export const logfireConfig: LogfireConfig = DEFAULT_LOGFIRE_CONFIG
 
 export function configure(config: LogfireConfigOptions = {}) {
-  const { otelScope, scrubbing, ...cnf } = config
+  const { errorFingerprinting, otelScope, scrubbing, ...cnf } = config
 
   const env = process.env
 
-  if (otelScope !== undefined || scrubbing !== undefined) {
-    logfireApi.configureLogfireApi({ otelScope, scrubbing })
+  if (errorFingerprinting !== undefined || otelScope !== undefined || scrubbing !== undefined) {
+    logfireApi.configureLogfireApi({ errorFingerprinting, otelScope, scrubbing })
   }
 
   const token = cnf.token ?? env.LOGFIRE_TOKEN