• Custom Rulesets: Create custom rules to lint JSON or YAML objects
• Ready-to-use Rulesets: Validate and lint OpenAPI v2 & v3.x and AsyncAPI Documents
• API Style Guides: Automated API Style Guides using rulesets improve consistency across all your APIs
• Ready-to-use Functions: Built-in set of functions to help create custom rules. Functions include pattern checks, parameter checks, alphabetical ordering, a specified number of characters, provided keys are present in an object, etc.
• Custom Functions: Create custom functions for advanced use cases

• 🧰 Installation
• 💻 Usage
• 📖 Documentation
• ℹ️ Support
• 🌎 Real-World Rulesets
• ⚙️ Integrations
• 👏 Contributing
• 🌲 Sponsor Spectral by Planting a Tree

The easiest way to install spectral is to use either npm:

npm install -g @stoplight/spectral-cli

Or yarn:

yarn global add @stoplight/spectral-cli

You can find more installation methods here.

Spectral, being a generic YAML/JSON linter, needs a ruleset to lint files. A ruleset is a JSON, YAML, or JavaScript/TypeScript file (often the file will be called .spectral.yaml for a YAML ruleset) that contains a collection of rules, which can be used to lint other JSON or YAML files such as an API description.

To get started, run this command in your terminal to create a .spectral.yaml file that will use Spectral's predefined rulesets based on OpenAPI or AsyncAPI:

echo 'extends: ["spectral:oas", "spectral:asyncapi"]' > .spectral.yaml

If you would like to create your own rules, check out the Custom Rulesets page.

Use this command if you have a ruleset file in the same directory as the documents you are linting:

spectral lint myapifile.yaml

Use this command to lint with a custom ruleset, or one that's located in a different directory than the documents being linted:

spectral lint myapifile.yaml --ruleset myruleset.yaml

• Documentation
  • Getting Started - The basics of Spectral.
  • Rulesets - Understand the structure of a ruleset so you can tweak and make your own rules.

Once you've had a look through the getting started material, some of these guides can help you become a power user.

• Different Workflows - When and where should you use Spectral? Editors, Git-hooks, Continuous Integration, GitHub Actions, wherever you like!
• Using the command-line interface - Quickest way to get going with Spectral is in the CLI.
• Using the JavaScript API - Access the raw power of Spectral via the JS, or hey, TypeScript if you want.
• Custom Rulesets - Need something more than the core rulesets provide? Fancy building your own API Style Guide? Learn how to create a custom ruleset.
• Custom Functions - Handle more advanced rules, by writing a little JavaScript/TypeScript and calling it as a function.

If you need help using Spectral or have any questions, please use GitHub Discussions, or visit the Stoplight Community Discord. These communities are a great place to share your rulesets, or show off tools that leverage Spectral.

If you have a bug or feature request, please create an issue.

• Adidas - Adidas were one of the first companies to release their API Style Guide in a written guide and a Spectral ruleset. Lots of good rules to try in here.
• APIs You Won't Hate - An opinionated collection of rules based on advice in the APIs You Won't Hate community.
• Azure - Ruleset and complimentary style guide for creating OpenAPI 2 or 3 definitions of Azure services.
• Box - Lots of Custom Functions being used to enforce good practices that the Box API governance folks are interested in.
• DigitalOcean - Keeping their OpenAPI nice and tidy, enforcing use of $ref (probably to minimize conflicts), naming conventions for Operation IDs, and all sorts of other handy OpenAPI tips.
• Tranascom - Don't even think about using anything other than application/json.

Here are more real-world examples of Spectral in action.

• GitHub Action - Lints documents in your repo, built by Vincenzo Chianese.
• Jetbrains Plugin - Automatic linting of your OpenAPI specifications and highlighting in your editor.
• Stoplight Studio - Uses Spectral to validate and lint OpenAPI documents.
• VS Code Spectral Extension - All the power of Spectral without leaving VS Code.

If you're using Spectral for an interesting use case, contact us for a case study. We'll add it to a list here. Spread the goodness 🎉

If you are interested in contributing to Spectral, check out CONTRIBUTING.md.

• Mike Ralphson for kicking off the Spectral CLI and his work on Speccy
• Jamund Ferguson for JUnit formatter
• Sindre Sorhus for Stylish formatter
• Ava Thorn for the Pretty formatter
• Julian Laval for HTML formatter
• @nulltoken for a whole bunch of amazing features

Spectral is 100% free and open-source, under Apache License 2.0.

If you would like to thank us for creating Spectral, we ask that you buy the world a tree.