Modular browser agent to exclude unused features like session replay (rrweb)

[isaacunderwood]

Summary

Hi team 👋

We’re currently using @newrelic/browser-agent in a production app shell architecture and trying to reduce our initial bundle size.

Even when configuring a slimmed down Agent using guidance in the README, excluding Session Replay and even just creating a blank Agent with no features passed in - I can see the final bundle still includes the full rrweb library. This adds ~500 KB parsed (150–200 KB gzipped) to our critical path.

This results in rrweb being included in the bundle regardless of whether session replay is used or enabled. Tree shaking cannot eliminate potentially due to static import structure internally within the agent.

Desired Behavior

Using the Agent to explicitly compose features should result in only those features being bundled. If SessionReplay is not imported or registered, rrweb should not be included in the output bundle.

Possible Solution

Additional context

We’re trying to keep our app shell lean and performant. Currently, New Relic contributes the largest chunk of our bundle size, and rrweb (which we don’t use) accounts for a significant portion of that.

Thanks 🙏

[workato-integration]

https://new-relic.atlassian.net/browse/NR-410109

[metal-messiah]

Thanks for reporting this @isaacunderwood . This is actually top of mind for us right now. Our next release features some changes to the way we structure our imports to hopefully stop web-bundlers from creating lazy chunks for files that are not actually used. Would love some follow-up to see if the issue gets resolved for you on the next release, which is tentatively scheduled for next Monday.

[isaacunderwood]

@metal-messiah Thanks so much for the quick response, that's awesome to hear!

I'll keep an eye out for the next release and will be sure to let you know if it improves things for us 😃

Appreciate the work on this!

[cwli24]

@isaacunderwood Could you try v1.290.0 and let us know of any update to this issue?

[isaacunderwood]

@cwli24 sorry low on capacity - but I will give it a try as soon as I can 🙂

[metal-messiah]

Hi @isaacunderwood just following up one more time before we close this issue! Any luck on updating the agent build?