FEATURES

Capture, change and automate every request.

Probe is a debugging proxy and API client for macOS and Windows. Everything on this page ships in the same app, free during the beta.

CAPTURE

Decrypt traffic from every device you test on.

Point a phone, a simulator or a desktop app at Probe and every HTTP and HTTPS request shows up decrypted, in real time.

Scan to install on your phone: a QR code that opens the certificate download

  • HTTPS interception

    A full man-in-the-middle proxy with auto-generated certificates, trusted by iOS, macOS, Android and Windows.

  • Mobile device debugging

    Inspect traffic from iPhones, iPads and Android devices on your local network. Install the certificate by scanning a QR code.

  • Pre-configured terminal

    Open a shell already routed through Probe: Terminal.app or iTerm2 on macOS, Windows Terminal or PowerShell on Windows. curl, python, ruby, go and Node clients are captured.

Find the request that matters.

Structure view grouping captured requests into a tree of domains and paths

  • Structure view

    Group requests by domain and URL path in a tree instead of scrolling a flat list.

  • Domain watch

    Unwatched domains collapse to a summary. Watched domains show every request.

  • Filtered lists

    Save filtered lists that isolate traffic by domain, method, status code or custom criteria.

  • Sessions

    Save captured traffic as a session, then export or import session files to share with your team.

MODIFY

Test every edge case without changing code.

Produce what your backend won't give you on demand: a slow network, a staging server, a missing endpoint.

Map Remote rules sending api.example.com and cdn.example.com to staging hosts

  • Breakpoints

    Pause requests or responses by URL pattern, edit headers and body, then resume or abort.

  • Map Local

    Answer any endpoint with a local file or an inline JSON, XML or HTML body, with custom status, headers and latency.

  • Map Remote

    Send matching requests to a different upstream, such as a mobile build to staging, with path wildcards.

  • Mock Server

    A standalone local server on port 9100. Create a mock from any captured response.

  • JavaScript scripting

    Rewrite live requests and responses with JavaScript script rules.

  • Network throttling

    Global profiles like 3G and LTE, plus scoped rules for a host, URL glob or app.

AUTOMATE

Build requests by hand. Run them in CI.

Next to the proxy sits a full API client. Save requests into collections, chain them into flows, and run those flows anywhere.

Composer with a GraphQL request to api.example.com/graphql and its query editor

A full API client
next to your traffic.

  • HTTP and GraphQL

    Build requests from scratch. GraphQL gets a query editor with schema docs.

  • Collections and environments

    Organize requests into collections, with auth, history and variables per environment.

  • Import and export

    Import from cURL or Postman. Copy code as cURL or Axios, or export to Postman v2.1.

Chain requests into flows.

A loop node, each, running three iterations with 3 ok and 0 failed

  • Visual canvas

    Chain requests with extractions, assertions, conditions, loops, sub-flows and scripts.

  • Run anywhere

    Start the same flow from the app, the REST API, MCP or the headless CLI.

dart run flow_engine:probe_flow \
run smoke.flow --json
exit 0every assertion passed
exit 1an assertion failed

AI AGENTS

Hand your traffic
to an AI agent.

MCP server with 110+ tools

Connect Claude Code, Cursor, Codex or any MCP client. Your agent can inspect traffic, replay requests, set breakpoints and create Map Local, Map Remote and Mock rules.

EXAMPLE TOOLS

  • Inspect trafficprobe_list_traffic
  • Replay and diffprobe_replay_request
  • Breakpointsprobe_create_breakpoint
  • Map Local & Remoteprobe_create_map_local_rule
  • Mock Serverprobe_create_mock_rule
  • Scriptingprobe_add_script_rule
  • Flowsprobe_run_flow
  • Filesprobe_remote_fs_list_dir
  • WebSocketprobe_ws_get_frames
  • and 80+ more

WORKS WITH

Claude Code · Cursor · Codex ·
any MCP client

FILES

Browse and edit remote files without leaving Probe.

Connect to SFTP, FTP/FTPS, S3 and WebDAV servers. Each connection opens as a tab next to your traffic, with a transfer queue, edit-in-place and keychain-backed credentials.

The Files tab connected to web-01.example.com over SFTP: the Connections sidebar, the file table with sizes, dates, kinds and permissions, and the transfer queue with uploads and downloads in progress

Four protocols, one browser.

Connect over the protocol your server speaks. The browser, transfers and file operations work the same across all of them.

SFTP
SSH file transfer with host-key verification (trust on first use).
FTP / FTPS
Plain FTP, plus FTPS over TLS in explicit or implicit mode.
S3
Amazon S3 and S3-compatible stores: MinIO, Cloudflare R2 and custom endpoints.
WebDAV
Any WebDAV server, including Nextcloud and ownCloud.

Work on remote files like local ones.

Each connection opens as a tab next to your traffic, and live connections stay listed in the sidebar.

The Connections sidebar listing prod-assets (S3), web-01.example.com (SFTP) and files.example.com (WebDAV)

  • Browse in a familiar file view

    The file table shows Name, Size, Modified, Kind and Unix permissions (drwxr‑xr‑x), as a flat list or a tree, with a breadcrumb bar.

  • Transfer queue

    Uploads and downloads run through a docked queue with per-file progress, speed, and pause, resume and cancel.

  • Edit remote files in place

    Open a remote file in your default editor; Probe uploads every save.

  • File operations

    Rename, delete, create folders and download. A read/write/execute grid sets permissions and writes the octal mode.

  • Bookmarks that keep secrets safe

    Reconnect in one click. Passwords and S3 secret keys go to the macOS Keychain or Windows Credential Manager, never to a plaintext file.

Let your agent move the files.

An agent can list directories, move files and drive transfers through the probe-mcp server and the internal REST API.

The agent only uses connections you open in the app. No tool connects to a server.

MCP TOOLS

  • probe_list_remote_fs_connections
  • probe_remote_fs_list_dir
  • probe_remote_fs_mkdir
  • probe_remote_fs_rename
  • probe_remote_fs_delete
  • probe_remote_fs_download
  • probe_remote_fs_upload
  • probe_remote_fs_transfers

MORE

More than an
HTTP proxy.

Probe also shows WebSocket frames, runs on a proxy core written in Rust, and speaks English, Vietnamese and Japanese.

  • WebSocket

    Inspect frames of intercepted WebSocket connections, or open your own client tab.

  • Built with Rust

    The proxy core is written in Rust;
    the app UI is Flutter.

  • Multilingual

    English, Tiếng Việt and 日本語, with more languages coming.

Stop guessing.
See the request.

Download for macOSDownload for Windows
Read the docs