APIs You Won't Hate: API Style Guide

Make your APIs "better" according to APIs You Won't Hate, with this slick command line tool that'll run on your OpenAPI.

Installation

npm install --save -D @apisyouwonthate/style-guide
npm install --save -D @stoplight/spectral-cli

Usage

Create a local ruleset that extends the style guide. In its most basic form this just tells Spectral what ruleset you want to use, but it will allow you to customise things, add your own rules, turn bits off if its causing trouble.

cd ~/src/<your-api>

echo 'extends: ["@apisyouwonthate/style-guide"]' > .spectral.yaml

If you're using VS Code or Stoplight Studio then the NPM modules will not be available. Instead you can use the CDN hosted version:

echo 'extends: ["https://unpkg.com/@apisyouwonthate/[email protected]/dist/ruleset.js"]' > .spectral.yaml

Note: You need to use the full URL with CDN hosted rulesets because Spectral cannot follow redirects through extends.

Next, use Spectral CLI to lint against your OpenAPI description. Don't have any OpenAPI? Record some HTTP traffic to make OpenAPI and then you can switch to API Design-First going forwards.

spectral lint api/openapi.yaml

You should see some output like this, letting you know there are a few more standards you could be using (shout-out to Standards.REST):

/Users/phil/src/protect-earth-api/api/openapi.yaml
  18:7   warning  api-health               Creating a `/health` endpoint is a simple solution for pull-based monitoring and manually checking the status of an API.  paths
  18:7   warning  api-home                 Stop forcing all API consumers to visit documentation for basic interactions when the API could do that itself.           paths
  36:30  warning  no-unknown-error-format  Every error response SHOULD support either RFC 7807 (https://tools.ietf.org/html/rfc7807) or the JSON:API Error format.   paths./v1/orders.post.responses[401].content.application/json
  96:30  warning  no-unknown-error-format  Every error response SHOULD support either RFC 7807 (https://tools.ietf.org/html/rfc7807) or the JSON:API Error format.   paths./v1/orders/{order}.get.responses[401].content.application/json
 112:30  warning  no-unknown-error-format  Every error response SHOULD support either RFC 7807 (https://tools.ietf.org/html/rfc7807) or the JSON:API Error format.   paths./v1/orders/{order}.get.responses[404].content.application/json

Now you have some things to work on for your API. Thankfully these are only warnings, which are not going to fail continuous integration (unless you want them to).

Backstory

You could write your API Style Guide as a giant manifesto and hope people see it, or you could automate your API style guide using a tool like Spectral so that your API Style Guide is enforced at the pull request level. This is an integral part of any successful API Governance program, otherwise you're all just wasting time covering the basics far too late in the game.

Spectral runs on top of OpenAPI and AsyncAPI, powering linting in editors, as a CLI tool, in continuous integration, etc., and comes with its own set of baked in OpenAPI v2/v3 rules. Making rules about how to write OpenAPI can help beginners write better OpenAPI, but its real power is using rules to make the actual APIs better and more consistent, before there is any programming involved.

This NPM package brings together all sorts of advice found in the books and blog posts from APIs You Won't Hate books. If you apply this to APIs in production, this is basically Phil Sturgeon judging your API for free instead of doing paid consulting. But if you can get this API Style Guide involved in the API Design-First workflow, you're getting free advice on how to design a better API before you waste any time coding, which then means fewer backwards-compatibility breaks as you fix things.

There are a bunch of other rulesets you can check out if you feel like making your own API Style Guides, or feel like contributing some new rules here via a pull request.

🎉 Thanks

• Andrzej - Great rules contributed to the Adidas style guide.
• Nauman Ali - Creating the no-global-versioning rule as part of his excellent style guide blog post series.

📜 License

This repository is licensed under the MIT license.

🌲 Sponsor

If you'd like to say thanks for this style guide, throw some money at Protect Earth, a charity that plants trees all over the United Kingdom, which has secured a 64 acre ancient woodland to restore. Phil spends all his time on this, both planting trees and writing APIs believe it or not!