Browser agent release notesRSS

v1.324.1

View this release on GitHub → for the full technical changelog and build size information.

Bug fixes

correct hasMeta/hasSnapshot flags on session replay harvests

Fixed an issue where Session Replay harvests could incorrectly report hasMeta and hasSnapshot as false in their payload metadata even though the harvested data included valid snapshot nodes — most noticeable shortly after a session switched from error-only to full recording, or whenever the recorder restarted. This metadata was used downstream to determine whether a given replay chunk was self-sufficient (i.e. whether it could bootstrap a replay on its own), so an incorrect false could cause valid replay data to be mishandled.

Security fixes

bump fflate to 0.8.3

Addressed CVE-2026-45820 - unzipSync could enter an infinite loop when parsing malformed ZIP64 archives

Support statement

New Relic recommends that you upgrade the agent regularly to ensure that you're getting the latest features and performance benefits. Older releases will no longer be supported when they reach end-of-life. Release dates are reflective of the original publish date of the agent version.

The following features are currently in limited preview and will not receive standard support:

• Micro frontend (MFE) monitoring via the register() API
• BrowserPerformance "resource" type events

New browser agent releases are rolled out to customers in small stages over a period of time. Because of this, the date the release becomes accessible to your account may not match the original publish date. Please see this status dashboard for more information.

Consistent with our browser support policy, v1.324.1 of the Browser agent was built for and tested against these browsers and version ranges: Chrome 144-154, Edge 144-154, Safari 18-27, and Firefox 146-156. For mobile devices, v1.324.1 was built and tested for Android OS 17 and iOS Safari 18-26.2.

v1.324.0

View this release on GitHub → for the full technical changelog and build size information.

Features

Improve script matching in manifest

Micro frontends registered with a manifest now have every resource a manifest matcher matches counted toward their MicroFrontEndTiming data. Previously each manifest asset was consumed by its first matching resource, so a broad matcher such as a RegExp for hashed chunks (e.g. /catalog-chunk-[a-f0-9]+.js/) only contributed one chunk to totalWeight, renderBlocking and the fetch/execute timing window. All matching chunks, whether already loaded or loaded shortly after register(), now contribute. Separately, when the same script URL is referenced more than once (for example a duplicated <script> tag, typically re-served from the browser cache), the agent now keeps the timing from the first load instead of overwriting it, so a cached duplicate can no longer make fetch and execution timing look shorter than the real load.

Enable distributed tracing for registered Micro Frontends

Enables distributed tracing (DT) for registered Micro Frontends (MFEs): an AJAX call made by a registered MFE now correctly roots its trace at that MFE's own entity, giving visibility into an MFE's own backend calls for the first time.

Bug fixes

prevent runaway log harvests from inflated attribute size

Fixed a bug where a page that repeatedly overwrites a custom attribute could cause the agent to send a separate logs request for every logged message, flooding the network and exhausting browser resources. The agent now tracks custom attribute size accurately when values are overwritten, limits how often each feature can harvest early, and still sends large batches promptly so that no logs are dropped while doing so.

fix(jserrors): reset stack hash memory on session reset

see https://new-relic.atlassian.net/browse/NR-626097 for details Resend the full stack trace once after a session reset, instead of a hash the backend may no longer be able to resolve due to cache TTLs.

find iframe entity script timings at registration

Registered iframe entities now identify the script that called register() when they are created, instead of after the parent agent responds. Previously the lookup ran after the registration round trip, when the calling script was no longer on the call stack, so the entity's asset, type and fetch timings could be missing or attributed to the agent's own script.

Support statement

New Relic recommends that you upgrade the agent regularly to ensure that you're getting the latest features and performance benefits. Older releases will no longer be supported when they reach end-of-life. Release dates are reflective of the original publish date of the agent version.

The following features are currently in limited preview and will not receive standard support:

• Micro frontend (MFE) monitoring via the register() API
• BrowserPerformance "resource" type events

New browser agent releases are rolled out to customers in small stages over a period of time. Because of this, the date the release becomes accessible to your account may not match the original publish date. Please see this status dashboard for more information.

Consistent with our browser support policy, v1.324.0 of the Browser agent was built for and tested against these browsers and version ranges: Chrome 144-154, Edge 144-154, Safari 18-27, and Firefox 146-156. For mobile devices, v1.324.0 was built and tested for Android OS 17 and iOS Safari 18-26.2.

v1.323.0

View this release on GitHub → for the full technical changelog and build size information.

Features

Harvest SR on switch from ERROR to FULL mode

Update agent to handle session replays the same way as session traces, and trigger a replay harvest when SR is switching from error to full mode.

Add internal adoption metrics for AJAX Payloads

Adds an internal metric measuring adoption of AJAX payload tracking for quality assurance and improvement purposes.

Bug fixes

fix(ajax): correct DT header timestamp to server time

Distributed tracing headers (traceparent/tracestate/newrelic) generated for AJAX requests now use the New Relic server-corrected timestamp when the agent's TimeKeeper has completed its RUM-based clock correction, rather than the browser's raw local clock value. This timestamp only affects the transport duration value a receiving backend APM agent computes for its own span -- it has no effect on any other browser telemetry.

Ensure timeKeeper readiness on Connector race condition

The new Connector in RUM v2 is patched to ready the TimeKeeper, critical to agent timestamp adjustments, under a minority-case race condition branch. This is behind the feature flag and should have no impact to any user right now.

Support statement

New Relic recommends that you upgrade the agent regularly to ensure that you're getting the latest features and performance benefits. Older releases will no longer be supported when they reach end-of-life. Release dates are reflective of the original publish date of the agent version.

The following features are currently in limited preview and will not receive standard support:

• Micro frontend (MFE) monitoring via the register() API
• BrowserPerformance "resource" type events

New browser agent releases are rolled out to customers in small stages over a period of time. Because of this, the date the release becomes accessible to your account may not match the original publish date. Please see this status dashboard for more information.

Consistent with our browser support policy, v1.323.0 of the Browser agent was built for and tested against these browsers and version ranges: Chrome 143-153, Edge 142-152, Safari 18-27, and Firefox 145-155. For mobile devices, v1.323.0 was built and tested for Android OS 16 and iOS Safari 18-26.2.

v1.322.0

Features

Include observer API for SPV events

Use the ReportingObserver API to catch securitypolicyviolation events that occurred prior to the agent loader execution. In practice, this mainly affects chromium browsers, as existing configs and bugs affect Firefox and Safari collection.

MFE Manifest

Adds an optional manifest to the register() API so a Micro Frontend can declare its own known assets (scripts, stylesheets, images, fonts), letting the agent accurately attribute errors, logs, AJAX calls, WebSockets, and resource-timing events to it — even for assets loaded by a script other than the one that called register(). An opt-in timingMethod also lets a manifest widen MicroFrontEndTiming fetch/execution windows across its declared assets.

Add registration validation warnings

Emits local debugging warnings if obvious issues are detected from supplied targets to the register API.

Bug fixes

Upgrade web-vitals from 4.2.4 to 6.2.1 to plug a listener leak

Upgraded the bundled web-vitals library from 4.2.4 to 6.2.1, fixing an unbounded document visibilitychange listener leak: web-vitals 4.x registers a permanent listener on every INP report cycle, so long-lived pages accumulate hundreds of listeners. Also absorbed the v5/v6 attribution API changes the agent is exposed to (the LCPAttribution.element → target rename and newly-optional INP/CLS attribution fields) with no change to the attribute names the agent emits.

Support statement

New Relic recommends that you upgrade the agent regularly to ensure that you're getting the latest features and performance benefits. Older releases will no longer be supported when they reach end-of-life. Release dates are reflective of the original publish date of the agent version.

The following features are currently in limited preview and will not receive standard support:

• Micro frontend (MFE) monitoring via the register() API
• BrowserPerformance "resource" type events

New browser agent releases are rolled out to customers in small stages over a period of time. Because of this, the date the release becomes accessible to your account may not match the original publish date. Please see this status dashboard for more information.

Consistent with our browser support policy, v1.322.0 of the Browser agent was built for and tested against these browsers and version ranges: Chrome 142-152, Edge 141-151, Safari 18-27, and Firefox 144-154. For mobile devices, v1.322.0 was built and tested for Android OS 16 and iOS Safari 18-26.2.

v1.321.0

Features

MicroFrontEndTiming attributes changes

MicroFrontEndTiming event attribute changes

Additions:

• registerUrl: The URL at the time the MFE was registered
• deregisterUrl: The URL at the time the MFE was deregistered or the page unloaded
• vitals.fcp.value: The value of the first contentful paint detected tied to the MFE DOM tree
• vitals.lcp.value: The value of the largest contentful paint detected tied to the MFE DOM tree
• vitals.cls.value: The value of the cumulative layout shift detected tied to the MFE DOM tree
• vitals.inp.value: The value of the interaction to next paint detected tied to the MFE DOM tree

Removals:

• pageUrl
• currentUrl

Add instrumentation to track races between tabs

Adds a supportability metric to track a race condition that occurs when another page runs at the same time with an updated session state.

improve v2 target standardization

Improves agent internals to provide an explicit reference for container agent targets while processing v2 MFE pathway data, rather than relying on side-effect driven undefined target assumptions.

Introduce v2 PageView & decouple connect service call

The old RUM request responsible for both retrieving app configurations and PageView generation is now split (temporarily under a feature flag). This makes the agent more resilient on problematic connect cycles or unsuccessful config retrieval, and the PageView event would no longer be the dependency blocking other events from harvesting.

Bug fixes

Ensure Session Replay's custom masker applies to non-inputs

Fixed an issue where the custom masker function was not applying to certain element types. The custom masker is applied to elements that are decorated with one of nr-umask CSS class or data-nr-unmask data attribute, allowing a node that would otherwise be masked to be overridden and its text contents exposed.

Support statement

New Relic recommends that you upgrade the agent regularly to ensure that you're getting the latest features and performance benefits. Older releases will no longer be supported when they reach end-of-life. Release dates are reflective of the original publish date of the agent version.

New browser agent releases are rolled out to customers in small stages over a period of time. Because of this, the date the release becomes accessible to your account may not match the original publish date. Please see this status dashboard for more information.

Consistent with our browser support policy, v1.321.0 of the Browser agent was built for and tested against these browsers and version ranges: Chrome 141-151, Edge 141-151, Safari 18-27, and Firefox 143-153. For mobile devices, v1.321.0 was built and tested for Android OS 16 and iOS Safari 18-26.2.

v1.320.1

Bug fixes

Avoid obfuscating keys and reserved system vals

Preserves all keys as well as reserved system values for AjaxRequest and Page View Timing events.

Apply hard cap to MFE FCP

Fixes an issue where MFE vitals could occasionally report out of bounds FCP/LCP values (e.g. after a browser tab freeze or suspend) instead of being dropped like other stale data.

Support statement

New Relic recommends that you upgrade the agent regularly to ensure that you're getting the latest features and performance benefits. Older releases will no longer be supported when they reach end-of-life. Release dates are reflective of the original publish date of the agent version.

New browser agent releases are rolled out to customers in small stages over a period of time. Because of this, the date the release becomes accessible to your account may not match the original publish date. Please see this status dashboard for more information.

Consistent with our browser support policy, v1.320.1 of the Browser agent was built for and tested against these browsers and version ranges: Chrome 140-150, Edge 140-150, Safari 18-27, and Firefox 142-152. For mobile devices, v1.320.1 was built and tested for Android OS 16 and iOS Safari 18-26.2.

v1.320.0

Característica

Mejora la capacidad de aplicar límites razonables a las métricas vitales de MFE

Se corrigió un error en el seguimiento de las métricas vitales del micro-frontend (MFE) de la API Register, donde la correlación de tiempo de un script podía reutilizarse después de volverse obsoleta, lo que causaba que el First Contentful Paint (y otras métricas vitales) se reportaran incorrectamente como hasta varios segundos más lentos de lo que realmente eran para los MFE que se vuelven a montar sin que su script subyacente se recargue (por ejemplo, en aplicaciones de una sola página).

Soporte de iframe de MFE - acceso beta

Agrega una interfaz para capturar datos de MFE encapsulados en un iFrame. Esto es experimental, está sujeto a cambios o eliminación total y no debe usarse en un entorno de producción hasta que se haya alcanzado el estado de GA

Corrección de errores

Deduplicar eventos de MFE autoinstrumentados

Soluciona el reporte duplicado de eventos autoinstrumentados (requests AJAX, errores de JS, logs de consola, actividad de WebSocket, etc.) cuando un micro-frontend se registra con la API register() varias veces. Anteriormente, un solo evento autoinstrumentado originado a partir de un script de MFE registrado repetidamente se reportaba una vez por registro — los eventos autodetectados ahora se agrupan en un solo reporte por ocurrencia real cuando se resuelven en el mismo script subyacente y el mismo MFE registrado id. Las llamadas explícitas controladas por la API (.addPageAction(), .log(), .noticeError(), etc.) y los eventos MicroFrontEndTiming permanecen por registro, como se esperaba, y los MFE distintos que comparten un script (por ejemplo, dos MFE diferentes registrados desde el mismo bloque <script> en línea) se siguen reportando de forma independiente.

Declaración de apoyo

New Relic recomienda que actualices el agente periódicamente para garantizar que obtengas las últimas características y beneficios de rendimiento. Las versiones anteriores ya no recibirán soporte cuando lleguen al final de su vida útil. Las fechas de lanzamiento reflejan la fecha de publicación original de la versión del agente.

Las nuevas versiones del agente del browser se lanzan a los clientes en pequeñas etapas a lo largo de un periodo de tiempo. Debido a esto, la fecha en que el lanzamiento esté disponible en su cuenta puede no coincidir con la fecha de publicación original. Consulte este dashboard de estado para obtener más información.

De acuerdo con nuestra política de compatibilidad de navegadores, la versión 1.320.0 del agente de Browser se creó y probó para estos navegadores y rangos de versiones: Chrome 140-150, Edge 140-150, Safari 18-27 y Firefox 142-152. Para dispositivos móviles, la v1.320.0 se compiló y probó para Android OS 16 e iOS Safari 18-26.2.

v1.319.0

Features

MFE vitals improvements

Implement quality of life improvements on the collection of MFE vital timings.

• If no FCP value is observed within 10 seconds, shut down observers for memory saving and outlier control.
• Decorate observed DOM trees with the MFE instance ID to facilitate debugging and prevent double-instrumentation of the same DOM tree from multiple instances pointed at the same MFE target.

Automatically Detect MFE Web Sockets

Add support for automatic Micro Frontend (MFE) attribution of WebSocket events. Previously, WebSocket events were only ever automatically captured globally by the container browser application. With this change, the agent cross-compares the call stack signature of the WebSocket method to the call stack signature of the MFE module that registered with the register API. If the file that is responsible for registering with the browser agent is found in the call stack signature of the WebSocket method being triggered, that event will be attributed to the MFE instead of the container.

Do not obfuscate attribute keys

Do not obfuscate attribute keys in our addCustomAttributes method for the BEL serializer. This change affects attributes in AjaxRequest, PageViewTiming, and BrowserInteraction (soft nav only) events.

Bug fixes

Avoid capturing agent AJAX payloads

Prevent the AJAX capture_payloads feature from capturing the agent's own telemetry requests (harvests to NR beacon endpoints).

Keep Ajax payload out of unrelated events

Drops captured AJAX request + payload info from unrelated events (AJAX timeslice metrics, session trace) via a shared params object.

Support statement

New Relic recommends that you upgrade the agent regularly to ensure that you're getting the latest features and performance benefits. Older releases will no longer be supported when they reach end-of-life. Release dates are reflective of the original publish date of the agent version.

New browser agent releases are rolled out to customers in small stages over a period of time. Because of this, the date the release becomes accessible to your account may not match the original publish date. Please see this status dashboard for more information.

Consistent with our browser support policy, v1.319.0 of the Browser agent was built for and tested against these browsers and version ranges: Chrome 139-149, Edge 139-149, Safari 18-27, and Firefox 142-152. For mobile devices, v1.319.0 was built and tested for Android OS 16 and iOS Safari 18-26.2.