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Current configured baseUrl = / (default value)

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Optic documents your APIs as you build them
by observing development traffic and learning your API's behavior
Detects API changes before they go live
by diffing traffic against the current specification
Provides an accurate API changelog during Code Review
by making your Pull Requests display both API and code changes
StarOpen Source, Free, Developed in the Open
Latest Release
Optic CLI v9.x.x
1 day ago
Get Started
Optic: the Git for APIs
5 months ago
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Recent Posts
Optic on Software Engineering Daily
8 months ago
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API CLI makes documenting endpoints and detecting changes easy
Review API diffs in Optic's interactive GUI

Optic ensures all API changes are documented and reviewed

Imagine Git, but for your APIs. Optic Documents your existing APIs in minutes by observing traffic, and learning how each endpoint behaves. It then diffs your team's development and test traffic as they your work to catch API changes and ensure each change is documented and reviewed before getting deployed.
our project is built around core principles:
  • Working with API specifications should be developer-friendly & accessible to everyone
  • Documenting new endpoints should feel like Git-adding a file
  • Every API change should be easy to document and review in Pull Requests
Optic is a smart, simple, and straightforward solution to a real world problem every company faces.

Kin Lane
The API Evangelist Chief Evangelist, Postman
Traffic-driven API development and ops is the the future of handling the skyrocketing complexity of API landscapes. Thats is why I am really excited to see efforts like Optic.

Zdenek Nemec

Developer-Friendly workflows

Optic is a Git-like tool that uses development traffic to version the behavior of your APIs. Changes to existing endpoints produce diffs while new endpoints can be documented and added to your specification in seconds. Get the benefits of OpenAPI, without learning the spec or writing YAML.
Runs fast in any dev stack (thanks for the boost Rust community!):
npm start
api start
Just install the API CLI and setup aliases for the commands you use most during development. Start using the aliases when you develop so Optic can observe/diff traffic.
Use api status to review API diffs:
  • Document new endpoints in seconds
  • Propose API changes to your team without learning OpenAPI.

Changelogs in every Pull Request

Optic makes API changes explicit during Code Review so your team understands how the API will change when the PR is merged.
🚦 Prevent Breaking Changes
Discover breaking changes before they're merged. Request compatible changes in code review, or coordinate the breaking changes with consumers.
🔎 API First
Adding explicit API changelogs in PRs facilitates discussion and leads to better API design. It's also a great way to make sure unintended API changes don't get deployed.
✅ Updated Docs
No more doc drift. When you approve an API change Optic also updates the specification.

DEMO: GitHub's API in Optic

Optic's UI is like a Git client, but for reviewing API diffs, finding API breaks/bugs early, and updating your specifications. In these two demos you can explore what it's like to use Optic with GitHub's API.
Hover to Start Interactive Demo

API-first workflows built for awesome developers. Try Adding Optic to your API

5-10 min setup

When the CLI is installing, be sure to join the community.

StarOpen Source, Free, Developed in the Open