Yaak

An API client that sends HTTP, GraphQL, gRPC, WebSocket, and SSE requests, solving the problem of testing and debugging APIs across multiple protocols in one workspace. It targets developers and engineering teams of all sizes, from freelancers to enterprises, who need a local-first tool. It differentiates by being local-only with no account, plain-file Git sync, and a CLI for agents, positioning as a private, open-source alternative to cloud-based clients.

Key features

• Send HTTP, GraphQL, gRPC, WebSocket, SSE requests
• Works offline with no account
• Plain-file Git sync
• CLI for agents
• Dynamic request templating
• Full request debugging
• Built-in Git collaboration
• Multi-window support
• Import from Postman, Insomnia, OpenAPI, Curl, Swagger
• Authentication: OAuth 1/2, AWS v4, JWT, Basic, Bearer, API Key, Custom
• Encrypted secrets with ChaCha20-Poly1305
• Zero telemetry
• Open source (MIT)
• No built-in AI, connect own agents via CLI or MCP