Playwright

Browser e2e · Web apps · stage: browser-e2e

Browser e2e verification with frontend, API health, and accessibility smoke specs.

Coding agents are good at editing components and terrible at noticing they broke the page. The Playwright plugin closes that gap: every agent session gets a browser-e2e stage that drives the app the agent just changed, in a real browser, against the slot’s own running instance.

HAR gives each agent slot its own ports, so parallel agents each test their own copy of the app — no shared staging environment, no cross-agent interference. A change is only “done” when the browser agrees.

What it installs

A browser-e2e test stage registered in .har/stages.json and added to verificationStages, so har env verify runs it automatically.
Playwright configuration wired to the slot’s computed BASE_URL and ports.
Frontend, API health, and accessibility smoke specs as a starting point.
Pinned devDependencies and npm scripts merged into package.json.
A GitHub Actions workflow from the official Playwright recipe (skip with --skip-ci).

Requirements

Node.js project (the plugin merges package.json)
Browsers via npx playwright install

Artifacts & evidence

HTML reports, traces, and screenshots land under .har/artifacts/browser-e2e/ in the main repo — inspectable evidence for every run, kept out of the worktree.

Adapting it to your repo

The shipped specs are smoke-level on purpose: adapt selectors and URLs to your app after installation, then grow the suite where agents break things most.
Full verification runs the stage whenever it is listed in verificationStages — the plugin updates that list for you.

Playwright docs Plugin install guide