I built a free, open-source Postman alternative in Go: no account, collections are just YAML files

Description and use

Gostman is a free, open‑source API client that runs without an account, stores collections as YAML, and supports CI, load testing, and coding‑agent integration.

Problem

API clients often require an account before sending requests, hindering quick testing and automation.

Outcome

Gostman enables account‑free API testing across REST, GraphQL, gRPC, WebSocket, and more, with CI integration, secret management, and coding‑agent support.

Workflow

• 1. Install Gostman via Go: go install github.com/kunalgoesbyken/gostman/cmd/gostman@latest
• 2. Create a collection folder with YAML files
• 3. Run requests from the CLI or desktop app
• 4. Use gostman run in CI to execute collections and generate reports
• 5. Expose collections to coding agents with gostman mcp

Evidence

I got tired of API clients that want an account before I can send a single request, so I built Gostman: a free, MIT‑licensed API client for REST, GraphQL, gRPC and WebSocket.

Source

Collections are plain YAML in a folder, so they diff and review in Git like any other code.

Source

gostman run exits non‑zero on failure and writes text, JSON, JUnit and HTML reports.

Source

gostman mcp exposes a collection to agents like Claude Code, Codex or Cursor so they can call your requests without seeing your secrets.

Source