macOS · Windows · native
The API client that
doesn't eat your laptop.
Impostor is a fast, local API workspace with a Rust core — full HTTP, every auth scheme, scripting, WebSocket and gRPC — in a footprint a fraction of Electron-based tools.
No account required to try. Git-friendly, secrets in your OS keychain.
Everything you reach for, built in
Native, not Electron
A Rust core in an OS-native webview. Starts instantly and idles in a fraction of the RAM a Chromium-based client needs.
Full HTTP
All methods, params, headers, and bodies (raw, form, multipart). Gzip/brotli/deflate, redirects, timeouts, and a shared cookie jar.
Every auth scheme
API key, Bearer, Basic, OAuth 2.0 (client-credentials + auth-code/PKCE), and mTLS with PEM or PKCS#12 client certs.
Scripting
Pre/post-request JavaScript with a Postman-style pm.* API — variable extraction, tests, and chaining, sandboxed and fast.
WebSocket & gRPC
A live WebSocket console and a dynamic gRPC client (server reflection or .proto) for unary and streaming calls.
Git-friendly storage
Workspaces are flat YAML — one request per file, clean diffs. Secrets live in your OS keychain, never on disk.
Try it in under a minute.
Download the signed build for your platform and open your first request.
Download Impostor