DEBUGGING PROXY · API CLIENT

See what your app really sends.

Debug HTTPS traffic from iPhone, Android and desktop apps, mock APIs and automate requests, in one app for macOS and Windows. Works with AI agents via MCP.

Download for macOSDownload for Windows

Free during beta · macOS 12+ · Apple Silicon & Intel · Windows 10+

Probe's main window: the sidebar with captured domains and apps, the list of HTTP requests with method, URL, status and timing, and the request details

CAPTURES TRAFFIC FROM

  • iPhone & iPad
  • Android phones
  • iOS Simulator
  • Android Emulator
  • macOS apps
  • Windows apps
  • Terminalcurl, Python, Node

CAPTURE

Every request, from every device.

Point an iPhone, an Android phone, a simulator or a desktop app at Probe. Every request lands in one list, decrypted, with headers, body and timing.

Response headers and a pretty-printed JSON body in the request detail panel

  • One-time certificate install

    Install Probe's certificate once per device. HTTPS requests then open up: headers, body and status.

  • Structure or Sequence

    Read traffic in the order it happened, or as a tree of domains and paths.

  • Search headers and bodies

    Find the request that carries a token, an ID or an error message.

  • Domain watch

    Unwatched domains show only their first request. Watch the ones you care about to see everything.

MODIFY

Change the response, not the code.

Backends rarely fail on cue. Edit a response in flight, answer an endpoint from a local file, or serve it from a mock server, and test every error state without changing app code.

  • Breakpoints

    Pause a request or response, edit the headers and body, then continue or abort.

    Breakpoint dialog pausing POST https://api.example.com/v1/payments with editable URL, headers and body, and Abort or Continue

  • Map Local & Map Remote

    Answer a matching URL with a local file or inline body, or send it to another host, such as staging.

    Map Local rules answering /api/users/* and /api/config with inline bodies

  • Mock Server

    A standalone server on port 9100. Turn any captured response into a mock.

    Mock Server running on port 9100 with mock rules for /api/users/1 and /api/orders

AUTOMATE

From a captured request to a test that runs in CI.

Chain requests on a visual canvas: pull a token out of login, assert on status and body, branch, loop, nest sub-flows. Then run the same flow from the app, the REST API, MCP or a headless CLI.

A flow on the canvas: Start, a login request whose token feeds a get_profile request, and the run report below
dart run flow_engine:probe_flow \
run checkout.flow --env \
BASE_URL=https://staging.example.com
✓login200
✓create_cart201
✗pay402
assertion failed: status == 200
exit code1

API CLIENT

Send it by hand
before you automate it.

HTTP and GraphQL, collections, environments, auth and history. Import from cURL or Postman, copy code as cURL or Axios, export to Postman v2.1.

Composer with a Guide API collection and a GET request to /users with its headers

AI AGENTS

Let your AI agent read the traffic.

MCP server with 110+ tools

Claude Code, Cursor and other MCP clients can search captured traffic, replay requests, diff responses, create mocks and run flows, without you copying anything out of Probe.

agent session

Why does checkout fail on my iPhone? Mock the error so I can test the UI.

probe_list_traffic

status_min: 400

POST/v1/payments402api.example.com

probe_create_mock_rule

method: "POST",
url_pattern: "/v1/payments",
status_code: 402

✓ mock rule created

probe_start_mock_server

port: 9100

✓ mock server running on port 9100

Checkout stops because
POST /v1/payments on api.example.com returns 402. I mocked the same 402 on Probe's mock server. To test the error UI, point the app's API base URL here:

http://127.0.0.1:9100

  • probe_list_traffic
  • probe_get_request
  • probe_replay_request
  • probe_diff_traffic
  • probe_run_flow
  • and 80+ more

Works with Claude Code, Cursor and any MCP client.

Also in the box

All of it ships in the same app,
free during the beta.

INSPECT

  • Structure view
  • Filtered lists
  • Favorites & saved sessions
  • Request diff
  • .prosession files
  • Domain watch

MODIFY

  • Breakpoints on request or response
  • Map Remote
  • JavaScript scriptingpro.*
  • Throttling profiles & rules
  • Mock from any response
  • Ignore hosts & clients

BUILD & MORE

  • Postman & cURL import
  • Code snippets (cURL, Axios)
  • GraphQL explorer
  • WebSocket client
  • Files over SFTP, FTP, S3, WebDAV
  • English · Tiếng Việt · 日本語

Stop guessing.
See the request.

Download for macOSDownload for Windows
Read the docs