Breakpoints

Breakpoints pause live requests, responses, or stream events so you can inspect and edit them before continuing.

What breakpoints can do

• Pause a request before it is sent.
• Pause a response before it is returned to the app.
• Pause a WebSocket or SSE stream event before it is processed.
• Edit URL, method, headers, body, and status code while paused.
• Resume, drop, or automatically apply edits to subsequent matching traffic.

Enable breakpoints

1. Open the Tools tab and tap Breakpoints.
2. Tap Add Breakpoint.
3. Choose a breakpoint type: Request, Response, or Stream.
4. Set a URL match pattern and enable the breakpoint.

Execution modes

Breakpoints have four execution modes, controlled from the breakpoint configuration:

• Normal: Pauses every matching request/response for manual editing.
• Log Only: Logs the hit without pausing. Useful for monitoring without interrupting traffic.
• Edit Once: Pauses the first hit so you can make edits. Those edits are automatically replayed on all subsequent matches.
• Always Apply: Pauses once to capture your edits, then silently applies them to every subsequent match without pausing again.

Conditions

Breakpoints can include conditions that must all pass before triggering:

• Header Exists: triggers only if a specific request/response header is present.
• Header Equals: triggers only if a header matches an exact value.
• Body Contains: triggers only if the body contains a substring.
• Body Regex: triggers only if the body matches a regular expression.
• Query Param Exists: triggers only if a specific query parameter is present in the URL.

When a breakpoint triggers

• Trace presents a breakpoint editor with the paused request or response.
• Make edits in the Overview, Headers, or Body tabs.
• Tap Send to continue or Drop to cancel the request.

Stream breakpoints

Stream breakpoints intercept individual WebSocket messages or SSE events. When triggered on a stream event, you can inspect and modify the event payload before it is forwarded.

Max hits

Set a Max Hits limit on a breakpoint to automatically disable it after it has been triggered a given number of times.