Breakpoint

A breakpoint stops a request on its way to the server, or a response on its way back to the app, and waits for you. While it’s paused you can change anything: the method, URL, headers and body of a request, or the status code, headers and body of a response. Use it to try an edge case once, by hand, without writing a script or a mock.

Set a breakpoint

1. Right-click a request in the traffic list and choose Tools › Breakpoint….

   Cloak Proxy creates a rule that matches the request’s method and URL (without the query string), turns Breakpoint on, and opens the rule. To start from scratch instead, choose Tools › Edit Breakpoint Rules… (⌥ ⌘ B) and click +.

2. Check the matcher. See Rules and matching for wildcards, regex and subpaths.

3. Under Pause on, choose what to stop:

   • Request: edit the method, URL, headers or body before it’s sent
   • Response: edit the status, headers or body before the app gets it

4. Make the request again in your app. Cloak Proxy plays a sound, brings itself to the front and opens the Breakpoint window.

1234

A Breakpoint rule created from a request. Both the request and the response pause.

1. The URL to pause on.
2. Pause the request before it's sent.
3. Pause the response before the app gets it.
4. Turns every breakpoint rule on or off.

×

Rule settings

Setting	Default	What it does
Name and matcher		Which requests pause. See Rules and matching.
Request: edit the method, URL, headers or body before it’s sent	On	Pauses the request after request scripts run and before Map Local, Mock Sets, Map Remote and the server.
Response: edit the status, headers or body before the app gets it	On	Pauses the response after response scripts run and before the app receives it.

Only the first matching breakpoint rule counts. If that rule pauses only responses, the request isn’t paused even if a later rule would pause it.

Edit a paused request

12345

A paused request. Edit anything, then click Execute.

1. Paused messages, oldest first, with their stage, method, time, URL and rule.
2. Abort: drop it and close the app's connection.
3. Cancel: send the original, ignoring your edits.
4. Execute: send it with your edits (⌘↩).
5. Continue All: send every paused message on, unedited.

×

The editor shows Request paused with the request number and the rule name. Under Request you can change:

Field	Notes
Method	GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS, CONNECT or TRACE.
URL	The full URL, including the query string. Change the host to send the request somewhere else.
Headers	Edit names and values in place, click Add for a new header, or click the minus button to remove one.
Body	Plain text. If it’s JSON, the editor shows Valid JSON with Format and Minify buttons, or Invalid JSON when a body starting with { or [ doesn’t parse.

Compressed bodies (gzip, deflate, Brotli) are decompressed before you see them, and the Content-Encoding header is removed, so you always edit readable text. Cloak Proxy recalculates Content-Length when you click Execute, so you don’t need to update it.

Edit a paused response

123

A paused response. Pick a status from Quick status to test error handling.

1. Status code. The reason phrase updates as you type.
2. Quick status: common codes in one click.
3. Format or minify a JSON body.

×

The editor shows Response paused and the request it answers (Response to GET …). You can change:

Field	Notes
Status code	Any number. The standard reason phrase is shown next to it and sent with the response.
Quick status	Sets the status to 200, 201, 204, 301, 304, 400, 401, 403, 404, 409, 422, 429, 500, 502 or 503.
Headers	Same editor as for requests.
Body	Same editor as for requests, decompressed.

Execute, Cancel or Abort

Each paused message waits until you decide what to do with it.

Button	Shortcut	What happens
Execute	⌘ ↩	Sends the message on with your edits.
Cancel	Esc	Sends the original message on and throws away your edits.
Abort		Drops the message. The app’s connection is closed, as if the network failed. The request shows as failed with Aborted at the request breakpoint or Aborted at the response breakpoint.
Continue All		At the bottom of the list. Sends every paused message on, unedited (the same as Cancel for each).

Binary bodies

If a body isn’t text, such as an image, the editor shows it empty. Leave it empty and Execute sends the original bytes. Type something and it replaces them.

The Breakpoint window

The window opens by itself when something pauses. You can also open it with Tools › Breakpoint Window, or by clicking N paused at breakpoint in the main window’s status bar.

Part	What it shows
Paused list	Every paused message: a Request or Response badge, the method, the time it paused, the URL and Rule: …. Select one to edit it.
Count	N paused at the bottom of the list.
Editor	The selected message.
Empty window	Nothing paused, with Manage Breakpoint Rules… to open the rules.

Several requests can be paused at once, for example when an app loads a page. Each one waits on its own; deciding on one doesn’t release the others.

Your app has its own timeout

Cloak Proxy waits as long as you need, but the app that made the request doesn’t. If you take too long, it may give up and show a network error. Use Continue All to release everything quickly, and turn Breakpoint off when you’re done. Quitting Cloak Proxy sends every paused message on unedited.

Breakpoints with other tools

• Request scripts run before the request pauses, so you see their changes. Response scripts run before the response pauses.
• Responses from Map Local and Mock Sets pause too, so you can tweak a mock before the app sees it.
• Editing the URL at the request breakpoint changes what Map Local, Mock Sets and Map Remote see. The response breakpoint still matches the original URL, so it pauses even if you changed the URL.
• Requests sent with Repeat or Compose pause like live traffic.

See What happens when several tools match for the full order.

Resolve breakpoints from an AI assistant

The MCP server has two tools for breakpoints: list_paused lists what’s waiting, and resolve_paused sends a message on with edits (send), unedited (send_original), or drops it (abort). See the MCP tools reference.

Related

ScriptingMake the same edit automatically on every matching request.

Map LocalAnswer a request with a fixed response instead of pausing.

Rules and matchingWildcards, regex and the order tools run in.

Debug a mobile appUse breakpoints on traffic from an iPhone or Android device.