What is the most important rule when designing an API?

When designing an API for your Application Frontend, what is your rule of thumb?

Comments

[ecyrbe]

These are some rules i apply that may not suit everyone:

• share Ideas with your team
• make sure you design user faced API
• make distinct APIs for product admins and standard users
• always design with security in mind
• design it with separation concern
• list your expected errors
• do not handle unwanted use cases because 'maybe it could be used'
• do not add complexity
• make it reviewed by another team

[Kolja]

Make it save for ways you dont think about in the first way.

[Doug Schwartz]

Don't make me think.

[Red Ochsenbein (he/him)]

Keep it consistent. (Used patterns and naming)
Don't make the frontend do the data processing.

[Teodor Kulej]

Do one task, and do it right, don't overthink it.

If you want a rule that's less verbal and more technical, refer to SOLID principles.

[decker]

Make it functional not technical, because the underlying technic can change more often than the desired function.

[Jonas Pfalzgraf]

Use the Open API standard with Swagger to simplify documentation and allow developers and users to work with it in a meaningful way.

[Gabriel Cecon Carlsen]

Modularity. Each part has its own resposaility (easy to maintain)