What callers need.
WHAT DOCUMENTATION MUST CONTAIN
How to authenticate Every endpoint, with parameters Request and response examples that work Every error and what it means Rate limits Versioning and change policy
WHY WORKING EXAMPLES MATTER MOST
Callers copy them, and a broken example wastes hours.
WHAT TO PROVIDE BEYOND REFERENCE
A getting-started guide reaching a first successful call quickly.
WHY
The first call is where most people give up.
WHAT TO INCLUDE IN IT
Obtaining credentials One complete working request What a successful response looks like
WHAT A SPECIFICATION PROVIDES
A machine-readable description of the interface.
WHAT THAT ENABLES
Generated documentation Generated client code Automated testing against the contract Mock servers
WHAT TO TREAT AS THE SOURCE OF TRUTH
The specification, with documentation generated from it.
WHY
Hand-written documentation drifts from behaviour.
WHAT TO AUTOMATE
Checking that the implementation matches the specification.
WHAT TO KEEP CURRENT
Everything, as part of shipping a change.
WHAT TO PUBLISH
A changelog, dated.
WHAT TO PROVIDE FOR TESTING
A sandbox, with test credentials.
WHY
Callers cannot develop against live data.
