Restura: One Free API Client for HTTP, gRPC, Kafka and MCP

Restura is an open-source API client that consolidates HTTP, GraphQL, gRPC, WebSocket, Socket.IO, SSE, Kafka, MQTT, and MCP support into a single tool, aiming to replace the patchwork of protocol-specific clients engineers typically juggle. It runs as a browser app, a native desktop app for macOS/Windows/Linux, or self-hosted via Docker, storing all data locally without requiring an account.

The project responds directly to shifts in the API tooling market — Postman's pricing changes and Insomnia's move to cloud-first sync — by keeping auth tokens, internal hostnames, and payloads on the user's machine. Its security design includes SSRF protections across all protocol paths, OS-level keychain encryption on desktop, ephemeral in-memory keys on web, and a sandboxed QuickJS WASM VM for request scripts with no filesystem or network access.

For engineering teams, the appeal lies in protocol breadth plus import compatibility with Postman, Insomnia, Bruno, OpenAPI, and Hoppscotch collections, along with workflow chaining, CI-runnable collections via a CLI, and built-in auth schemes like OAuth, AWS SigV4, and mTLS. The stack — React 19, Vite, Cloudflare Workers, Electron — keeps the same UI across web and desktop, swapping only the transport layer at runtime.