Actively in development — Early preview rollout planned for January 5th, 2026 • Preview release on: Jan 5, 2026

Version 0.1 Now Available

An open format for API collections

A modern, developer-first specification pioneered by Bruno for defining and sharing API collections. Designed for simplicity and collaboration.

Open Source

Git Friendly

Tool Agnostic

One Spec, Many Possibilities

A clear, open spec you can build on, adapt, and integrate anywhere.

📄

Plain YAML format

No proprietary formats. No binary files. Just readable YAML that you can edit in any text editor, diff in git, and understand at a glance.

Human readable

Git friendly

🔌

Works everywhere

Import into Bruno, execute via CLI, automate in CI/CD, generate docs, edit and run in VSCode - OpenCollection fits into every part of your workflow.

Bruno CLI CI/CD Docs VSCode

10x

Collaboration

∞

Possibilities

0

Lock-in

1

Specification

🔧

Variables

Define once, use everywhere. Switch between environments instantly. Keep secrets safe. Make your API collections truly portable.

🏠

Local

🚧

Staging

🚀

Production

{{baseUrl}}/api/v1/users

↓

https://api.myapp.com/api/v1/users

✅

Built-in testing

Write tests that actually run. Validate responses, check status codes, and ensure your APIs work as expected. CI/CD friendly out of the box.

Assertions

Post-response tests

All tests passed

✓ Status code is 200

✓ Response time < 500ms

✓ Contains user data