I wanted an API client that opens fast, keeps my data on my own machine, and does not ask me to log in. I could not find one I liked, so I wrote Rustman in Rust. It is free, it is open source, and it is yours to use.
reqwest, so no browser CORS limits, no size caps, no 30s timeouts.Pre-request and test scripts run on rustman-engine, a small interpreted language written from scratch in Rust — no embedded JS runtime, no pm.* API to memorize. It is small on purpose: env vars, headers, cookies, JWT decoding, base64, and JSON assertions, in a syntax simple enough for an AI to generate correctly from a plain-English request. Full grammar and built-ins are on the scripting docs page.
// inject a bearer token, only if one is set let token = env("access_token") if token != "" { set_header("Authorization", "Bearer " + token) }
// decode the response's JWT and stash claims let claims = jwt_decode(header("Authorization")) set_env("user_id", claims.payload.sub) test("status is 200", response.status == 200) let body = response.json() test("has a token", body.token != null)
How it stacks up against Postman and Bruno so you can make an informed switch.
| Feature | Rustman | Postman | Bruno |
|---|---|---|---|
| Price | Free forever | Freemium / $14mo | Free |
| Open source | ✓ | ✗ Proprietary | ✓ |
| Install size | ~30 MB | ~350 MB | ~100 MB |
| No account required | ✓ | ✗ Mandatory | ✓ |
| Zero telemetry | ✓ 100% local | ✗ Cloud sync | ✓ |
| Works offline | ✓ | Limited | ✓ |
| Native HTTP, no CORS | ✓ Rust/reqwest | ✗ | ✗ |
| Native GUI, no webview | ✓ iced | ✗ Electron | ✗ Electron |
| Git for collections | ✓ local + remote | ✗ | ✓ |
| WebSocket | ✓ | ✓ | ✗ |
| Code editor | ✓ syntect | Basic | Basic |
| Large response viewer | ✓ | ✗ | ✗ |
| Postman collection import | ✓ v2.1 | ✓ | ✓ |
| Multi-tab editing | ✓ | ✓ | Limited |
| Session restore | ✓ | ✓ | ✗ |
| Pre/post scripts | ✓ Rust-native | ✓ | ✓ |
Based on publicly available info. Postman pricing subject to change.
Free, open source, around 30 MB. No sign up. No telemetry. Just download and run.
Download Latest Release# Requires Rust 1.85+, a C toolchain, and CMake git clone https://github.com/animeshchaudhri/rustman cd rustman cargo build --release
Needs a Rust toolchain (1.85 or newer), plus a C compiler and CMake for the vendored libgit2, OpenSSL, and SQLite. The full guide is in docs/DEVELOPMENT.md.