Tiger

Tiger is a free, open source, git-native API client. A local-first, account-free Postman alternative with a built-in MCP server.

Download

Get the latest macOS and Windows builds from the releases page, or visit the website. Builds are not yet code-signed, so on macOS right-click the app and choose Open the first time.

Tiger is an open source API client where every request is a plain .tiger text file on disk. Commit your collections, branch them, and review API changes in pull requests the same way you review code. No account required. No cloud sync. No lock-in.

On top of the git-friendly storage model, Tiger adds a glass UI with light and dark themes, a full importer suite, an MCP server so AI assistants (Claude, Cursor) can run requests directly, and a request chaining system to capture response values into variables for the next call.

Why Tiger

• Collections as plain text in Git. A collection is a folder of .tiger files. Diff them, branch them, and review API changes in pull requests. Every field is human-readable.
• No account, fully offline, local-first. Tiger never phones home for your data. Everything lives in a folder you own.
• MCP server for AI assistants. Claude, Cursor, and any MCP-compatible assistant can list, read, and run requests from your collection without leaving the chat. Tiger is the only MCP API client built this way from the ground up.
• Environments and secrets. Named variable sets with {{variable}} interpolation in URLs, headers, query params, bodies, and auth fields. Secret variables are masked in the UI.
• Request chaining. Capture values from a response (status code, header, or a JSON path like body.data[0].id) and write them into environment variables for the next request.
• Dynamic variables. {{$uuid}}, {{$timestamp}}, {{$isoTimestamp}}, and {{$randomInt}} are re-evaluated on every send.
• OAuth 2.0, proxy, client certificates (mTLS). Client credentials grant, Bearer, Basic, and API key auth. HTTP/HTTPS/SOCKS proxy support. Custom CA bundles and client certificate authentication via PEM pair or PFX/PKCS12 file.
• GraphQL. Dedicated body type with a separate variables pane.
• SOAP and XML. Send raw XML bodies for SOAP/WS-* APIs the same way you would for REST.
• JSON prettify and minify. Format button and syntax highlighting in the editor and response panel, with Pretty/Raw and word-wrap toggles.
• Collection runner. Run every request in a collection or folder sequentially with live pass/fail verdicts from your script tests, capture chaining between requests, and a stop button.
• Performance runs. Fire N requests with a configurable concurrency level and get back min, max, avg, p50, and p95 timings.
• Multipart and file upload. multipart/form-data bodies mix text fields and file rows with a per-row file picker; file paths live in the .tiger format as @file: values.
• Response power tools. Search inside any response with Cmd/Ctrl+F (match cycling and highlights), preview HTML responses in a sandboxed frame, and view image responses inline.
• Keyboard-first. A shortcuts overlay on Cmd/Ctrl+/, tab cycling, close-tab, quick-create, and focus-URL shortcuts. Inline rename (double-click or F2) and drag-and-drop to move requests between folders.
• Import and export Postman, OpenAPI, and more. Import a Postman v2.0/v2.1 export, an Insomnia v4 export, a Bruno folder, an OpenAPI 3 / Swagger 2 spec, or a pasted curl command. Export collections back to Postman v2.1 or OpenAPI 3.0, and single requests as .tiger or curl.
• Code generation. Turn any request into a curl command or a JavaScript fetch snippet.
• Cookie jar. Persist cookies between sends and sessions, with automatic cross-origin stripping on redirects.

Tiger vs Postman vs Bruno

The .tiger format

One request per file. Readable in any editor, friendly to git:

meta {
  name: Create post
  seq: 2
}

post {
  url: {{baseUrl}}/posts
}

headers {
  Content-Type: application/json
  ~X-Debug: 1
}

body:json {
  { "title": "Hello from Tiger" }
}

auth:bearer {
  token: {{token}}
}

capture {
  postId: body.id
}

A ~ prefix disables a line without deleting it. The capture block writes response values into environment variables for the next request in the chain. Environments live in an environments/ subfolder:

meta {
  name: production
}

vars {
  baseUrl: https://api.example.com
  token: abc123
}

Getting started

npm install
npm run dev        # launch the app in development mode
npm test           # run the test suite
npm run package    # build distributables for your platform

Open a collection folder from the sidebar, or try examples/jsonplaceholder to see the format in action.

Connect an AI assistant (MCP)

Tiger ships an MCP server that gives AI clients safe, structured access to a collection. Build it once:

npm run build:mcp

Then register it in your AI client's config. For Claude Desktop, add this to claude_desktop_config.json:

{
  "mcpServers": {
    "tiger": {
      "command": "node",
      "args": ["/path/to/tiger/out/mcp/server.mjs", "/path/to/your/collection"]
    }
  }
}

The assistant gets four tools: list_requests, list_environments, get_request, and run_request. Every response includes the status code, timing, response headers, and a pretty-printed body. Your collection stays on disk; nothing is sent to any third party.

Privacy

Tiger sends anonymous usage analytics by default: app opened, request sent (method and status bucket only), and collection imported (source and count). It never records URLs, hostnames, header values, or bodies. The only identifier is a random app-local ID. Turn it off any time in Settings under Privacy.

Architecture

src/core      Pure TypeScript: format, interpolation, auth, request building,
              response formatting, captures, importers, exporters, codegen.
              No DOM, no Node dependency. Fully unit-tested.
src/main      Electron main process: windows, file IO, HTTP, settings, history.
src/preload   The narrow, typed IPC bridge.
src/renderer  React UI (glass).
src/mcp       The MCP server (stdio) and its filesystem store.

The core is dependency-free and fully unit-tested. The UI and the MCP server are thin layers on top of it.

Contributing

See CONTRIBUTING.md. The short version: tests first, keep core pure, match the existing style.

Support

Tiger is free and open source, built and maintained on personal time. If it saves you from a paid plan or just makes your day a little easier, you can buy me a coffee. Find me on LinkedIn (Taoufik Jabbari). It funds new features and keeps the project independent. Thank you.

License

MIT. See LICENSE.