Record and replay

For AI agents: this page is Markdown at https://squiggle.sh/docs/replay.md. Every docs page is listed at https://squiggle.sh/llms.txt, and all of them are one file at https://squiggle.sh/llms-full.txt.

A recording keeps everything your app did during a session: renders, screens, store changes, requests, errors and metrics. Replay it later and the Inspector, Performance and Analytics screens all work on it as if the app were running.

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A recorded session, on one timeline. Live, in your browser.Open in Studio

Replay an incidentStudio tour · 9 steps

Record a session

In Studio, press Record session in the device panel’s Capture menu. From the terminal:

Terminal
squiggle record                          # until you press Ctrl-Csquiggle record checkout --duration 60   # named, for 60 secondssquiggle record -o ./repro.sqrec         # to a file of your choice

Recordings are .sqrec files in .squiggle/recordings/. They aren’t videos: they hold what the app did, so they stay small and every tool can read them. squiggle record works while Studio is open. When an agent runs a program, a recording starts on its own, so a failure already comes with its replay.

Replay it in Studio

Open a recording on the Replay screen. You get a timeline to scrub, play at ×1, ×2, ×4 or as fast as possible, with markers where the screen changed. Under the timeline, a lane for each metric the recording has (renders per second, CPU, memory, frame rate, event-loop lag) shows its value at the playhead. Beside it, a list of events (screen changes, taps, errors, logs, requests, long tasks) highlights where you are; click one to jump there.

Click a component in the graph to see, at that moment, how often it had rendered, why it last rendered, and which props, state or context keys changed. A recording keeps which keys changed, not their values.

Share and follow up

  • The Performance and Analytics buttons on the Replay screen open the run the recording was made in. The Performance timeline moves with the replay’s playhead.
  • Copy report copies the cause, the stack, the numbers and the steps that led there as Markdown, ready for a ticket.
  • Make flow turns the taps and screen changes into a draft flow in incidents/. Add the assert that should hold, and the bug has a test.

Replay from the terminal

Terminal
squiggle replay                          # list recordingssquiggle replay checkout                 # replay onesquiggle replay checkout --speed 2

There is no device to wait for, so a replay runs as fast as possible unless you set --speed.

More

To turn a recording into a flow from the terminal, see Record and crawl.