Full Stack Debugging

We’ve been experimenting with using Replay MCP for full stack debugging, by recording both the frontend and the backend of an app and using an agent to investigate those recordings together to create a timeline spanning all the involved services.

The video below walks through this investigation for a bug in a slack style app which Astra wrote. After one user disconnects, the server broadcasts an update with all online users to everyone else. The disconnected user was not filtered out from this update, so the UI for other users shows them as still online.

Most user facing bugs involve steps in both the frontend and backend. With full stack debugging of both these pieces, an investigation agent can get a full understanding of the problem and provide supporting evidence for its conclusions. A coding agent can review the bug report and its evidence, and accurately fix the problem without having to guess about what happened.

Full stack debugging is not yet generally available, but you can visit https://full-stack-demo.replay.io/ to see this investigation and trigger new ones on recordings of a variety of scenarios in the same app.