A browser test does what a user does: it opens a page, types, clicks and checks what appears. When it fails, the question is always the same: what did the page look like, and what happened behind it? A screenshot answers the first half. The second half is on the server.

This book shows how to keep both. It describes the Playwright module of the Nasdanika SDK Runtime, which drives a browser with Playwright from Java against a server started for the test, and records the whole session in one OpenTelemetry trace:

• Steps are spans - The session runs in a span and each step is a child span.
• The server's work is in the step that caused it - Every request the browser sends carries the step's span, so the server's spans, logs and exceptions are its children.
• Screenshots are part of the record - The pictures taken before and after each step are log records in it, along with the browser's console, uncaught page errors, narration and an optional video of the session.
• The trace is a model - Saved with the runtime's telemetry model, a walk-through is a typed record of a scenario, with pictures, that people, programs and AI assistants can read.

The first part needs no code: why a browser test should leave a picture book and a trace, and the decisions behind the module. The second part walks through a small catalog application and a React application generated from Java models, then covers what a walk-through records and how the browser joins the trace across origins. The last part looks ahead to user guides, slide decks and narrated demo videos generated from recorded walk-throughs, which are planned.

Who it is for

• Java developers who test web applications end to end and want a failed test to show the page and the server's side of the failure together.
• People who document web applications and want screenshots retaken on every build.
• Architects who want traceability from a user's step in a browser to the code that served it.

How it keeps you honest

Every listing is included from the module's sources or tests and runs when the book is built. The figures are screenshots the tests took. Status labels mark what is PLANNED.

This is a Nasdanika Zephyr Book, an in-depth manual for one module of the Nasdanika SDK Runtime, and it stands on its own. The code needs Java 25 and Chrome, Edge or Playwright's Chromium. The text is licensed under CC BY 4.0 and the code under EPL-2.0.