Lostman — API Client for VS Code

The free, offline Postman alternative — right inside VS Code. No login, no account, no cloud sync: everything stays on your machine.

Open it with Ctrl+Shift+P → "Lostman: Open API Client".

Features

• REST requests (GET/POST/PUT/PATCH/DELETE/HEAD/OPTIONS) with params, headers, raw/JSON, form-data (file uploads) and x-www-form-urlencoded bodies
• GraphQL query + variables editor, WebSocket and SSE live consoles
• Auth: Bearer, Basic, API key, OAuth 2.0 (client credentials & authorization code with PKCE via your browser), Digest, AWS Signature v4
• Collections with folders, tabs, history with response snapshots
• Environments & globals with {{variable}} autocomplete, secret masking, .env import
• Request chaining ({{res.Login.body.token}}), pre-request & test scripts, collection runner with CSV/JSON data files
• Import/export Postman collections, import OpenAPI/Swagger specs and cURL commands
• Code generation: cURL, fetch, axios, Python, PowerShell, C#, Go
• Proxy support, client certificates (mTLS), streamed large responses, cookie manager
• 5 languages: English, العربية, Français, Español, Deutsch

Also available as a standalone desktop app for Windows and Linux: github.com/AliHammoud995/lostman