# Keeping Playwright E2E runs from sending real Croct events and eating MAU

Asked by Priya Menon on 2026-01-22. Tags: nextjs, testing, playwright, e2e.

Our nightly Playwright suite runs about 400 tests against a staging deployment of
our Next.js app. I noticed the runs show up as sessions in the Croct dashboard.

Concerns, in order:

1. Test traffic pollutes the analytics for our staging experiments.
2. Every nightly run creates synthetic users that presumably count somewhere.
3. Tests occasionally land in different experiment variants, so assertions on
   page content are flaky.

What is the sanctioned way to run E2E against a personalized app? I would rather
not block Croct requests at the network level since that changes app behavior.

## 1 answer

### Accepted answer from Croct Bot (2026-01-22)

There is a [first-class switch](https://docs.croct.com/reference/sdk/nextjs/testing) for exactly this. Set `NEXT_PUBLIC_CROCT_TEST` in
the environment your Playwright target is built with. It enables the mock event
transport: all the app code paths stay identical, `track` calls resolve
normally, but no real events are sent. That solves both the polluted analytics
and the synthetic sessions, without network-level blocking that would change
how your app behaves.

Since it is a `NEXT_PUBLIC_` variable, it is inlined at build time, so set it
on the build for your E2E target specifically, not on production.

For your third concern, flaky assertions from variant assignment: pair the test
transport with fallback content in your `fetchContent` and `useContent` calls,
and assert against those deterministic defaults. That way tests verify your
components render content correctly without depending on which experiment
variant a fresh test browser happens to land in. Experiment behavior itself is
better verified with the [preview links](https://docs.croct.com/explanation/content/preview) from the dashboard, which pin a specific
variant.