The latest articles on DEV Community by Kunal (@krockxz). https://dev.to/krockxz https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F978538%2F71dc3924-1f00-42cd-a288-a12ba758b990.png https://dev.to/krockxz en Kunal Mon, 26 Oct 2026 17:09:13 +0000 https://dev.to/krockxz/i-built-a-free-open-source-postman-alternative-in-go-no-account-collections-are-just-yaml-files-2kl7 https://dev.to/krockxz/i-built-a-free-open-source-postman-alternative-in-go-no-account-collections-are-just-yaml-files-2kl7 <p>I got tired of API clients that want an account before I can send a single request, so I built <strong>Gostman</strong>: a free, MIT-licensed API client for REST, GraphQL, gRPC and WebSocket. It runs as a desktop app, in the browser, and as a CLI.</p> <ul> <li>Web app (no install, no account): <a href="https://gostman.com/web" rel="noopener noreferrer">https://gostman.com/web</a> </li> <li>Source: <a href="https://github.com/kunalgoesbyken/gostman" rel="noopener noreferrer">https://github.com/kunalgoesbyken/gostman</a> </li> </ul> <h2> What it does </h2> <ul> <li> <strong>Protocols:</strong> REST, GraphQL (with a schema browser), gRPC (reflection or .proto files), WebSocket, Socket.IO, MQTT over WebSocket, Server-Sent Events, SOAP and MCP servers.</li> <li> <strong>Auth:</strong> Basic, Bearer, API key, OAuth 2.0 with PKCE, OAuth 1, Digest, AWS SigV4, NTLM, JWT Bearer and more.</li> <li> <strong>Collections are plain YAML in a folder</strong>, so they diff and review in Git like any other code. The desktop app has a Git panel.</li> <li> <strong>Testing:</strong> assertions, pre-request and post-response scripts, and a collection runner with CSV or JSON data files.</li> <li> <strong>CI:</strong> <code>gostman run</code> exits non-zero on failure and writes text, JSON, JUnit and HTML reports.</li> <li> <strong>Extras:</strong> load testing (<code>gostman load</code>), a secret scanner (<code>gostman scan</code>), a mock server, traffic capture and OpenAPI import.</li> <li> <strong>Secrets:</strong> OS keychain, HashiCorp Vault, AWS, Azure, Google Cloud, 1Password, Bitwarden and KeePassXC.</li> <li> <strong>Import:</strong> Postman, OpenAPI, Insomnia, HAR, Bruno, .http files and curl.</li> <li> <strong>Code generation</strong> for 13 languages, including cURL, Python, Go and Rust.</li> </ul> <h2> Using it with coding agents </h2> <p>I use coding agents every day, and the awkward part is handing them API credentials. <code>gostman mcp</code> exposes a collection to agents like Claude Code, Codex or Cursor so they can call your requests without seeing your secrets.</p> <h2> Under the hood </h2> <p>The desktop app is built with Go and <a href="https://wails.io" rel="noopener noreferrer">Wails</a>. The CLI is a single binary, so you don't need Node.js:<br> </p> <div class="highlight js-code-highlight"> <pre class="highlight shell"><code>go <span class="nb">install </span>github.com/kunalgoesbyken/gostman/cmd/gostman@latest </code></pre> </div> <p>There are also builds for Windows, macOS and Linux (.deb, AppImage, AUR). They aren't code-signed yet, so SmartScreen or Gatekeeper will ask you to confirm on first run.</p> <h2> Limits worth knowing </h2> <p>The web version sends requests through a small relay, so it can't reach localhost or private networks. Use the desktop app for those. Responses over 3 MB are truncated in the web version.</p> <h2> Feedback welcome </h2> <p>It's early and I'm building it in the open. If something is missing from your workflow, or an import from Postman or Bruno doesn't work, open an issue: <a href="https://github.com/kunalgoesbyken/gostman/issues" rel="noopener noreferrer">https://github.com/kunalgoesbyken/gostman/issues</a></p> <p>If you try it, I'd like to hear which features you actually use.</p> opensource go api webdev