Ferrum

FerrumAPI

Alpha

A native, local-first API client with the Postman basics, minus the bloat.

A desktop API client written in Rust, focused on the Postman basics: build a request, send it, organise it. Native GPUI app and local-first, with no Electron shell and no webview.

Download LauncherInstall with Ferrum Launcher

What FerrumAPI does

These are the features in the alpha. The request engine, storage and import/export are covered by automated tests; the GPUI interface has been launch-tested and is still being polished.

  • Request builder

    Method, URL, query params and headers, edited side by side with the response.

  • Auth

    Common authentication schemes configured per request instead of hand-written headers.

  • Request bodies

    Compose the body your API expects alongside the rest of the request.

  • Collections

    Group related requests so a project's API lives in one place.

  • Environments

    Switch between local, staging and production with {{variables}} substituted into URLs, headers and bodies.

  • History

    Look back at requests you have already sent.

  • Postman and cURL import

    Bring in Postman Collection v2.1 files and paste cURL commands to start from what you already have.

  • Code generation

    Turn a request into a snippet you can drop into code or a terminal.

Status: Alpha

FerrumAPI is in alpha. The Postman basics are in place; below is what is built today and what is not yet.

Built in the preview

  • Request builder: 7 methods, URL/params sync, headers with enable toggles
  • Bodies: raw, JSON, form-urlencoded, multipart, binary file
  • Auth: Basic, Bearer, API key, inherited from the collection
  • Collections with folders, environments and globals with {{vars}}
  • History, restored tabs, cancel and timeouts
  • Postman Collection v2.1 import/export, cURL import, cURL/Python/JS snippets
  • Local mock server per collection, with path params, conditions and delays
  • Webhook inspector: capture, inspect and replay incoming requests
  • Load test with requests per second and p50/p90/p99 latency

Not built yet

  • OAuth 2.0 and Digest auth
  • Pre-request and test scripts
  • Drag-and-drop between folders
  • Secrets in the OS keychain
  • WebSocket, GraphQL editor and gRPC
  • Light theme and soft-wrap in the response view
  • HTTPS mocks, templated mock bodies and a public tunnel for webhooks

Approach

  • Native Rust desktop app, no Electron
  • Local-first: collections and environments stay on your machine
  • Rendered with GPUI and the shared Ferrum UI, like every Ferrum app

Requirements & built with

Install
Ferrum Launcher (free, see Download)
Builds
macOS (Apple Silicon and Intel) and Linux x86_64
Built with
Rust, GPUI, reqwest + rustls, SQLite
Runtime
Native app, no Electron, no webview, no backend server
Data
Stored locally on your machine

Builds are free public GitHub Releases, installed through Ferrum Launcher. Only macOS has been smoke-tested so far.