API design for your Micro-SaaS: keep it simple

If your Micro-SaaS offers an API, keeping it simple from day one saves you and your users a lot of pain later.

REST and resource names

• Use nouns for resources: /users, /projects, /tasks. Avoid verbs in URLs.
• Use HTTP methods: GET (read), POST (create), PATCH or PUT (update), DELETE (delete). Same URL, different method.
• Return clear status codes: 200, 201, 400, 401, 404, 422, 500. Don’t always return 200 with an error in the body.

Versioning early

• Put the version in the path (e.g. /v1/...) or in a header. Path is easier to see and cache.
• When you need breaking changes, add a new version and deprecate the old one with a timeline. Avoid breaking v1 in place.

Documentation

• List every endpoint, method, request body and response. One source of truth (e.g. OpenAPI or a doc site) is enough to start.
• Add one or two request/response examples per endpoint. Developers copy-paste; examples get them going faster.
• If you can, offer a sandbox or test key so users can try the API without touching production.

Security and rate limits

• Use API keys or OAuth and document how to send them (header vs query). Prefer headers for secrets.
• Set rate limits from the beginning and document them. It’s easier to relax limits later than to add them when abuse appears.

A small, consistent API with clear docs and versioning will scale with your product without becoming a mess.