A JSON object is sometimes a fixed record, sometimes a Map<string, T> of arbitrary keys, and sometimes genuinely free-form. Use additionalProperties for dictionaries, properties plus additionalProperties:false for strict records, and an empty object for anything-goes payloads. Get it wrong and...
The server returns id, created_at, and version but must reject them on input; the client sends password and current_password that must never come back. One schema with readOnly and writeOnly properties models both directions and codegen splits it into request and response types automatically....
operationId becomes the method name in every generated SDK and tags become the namespace and the docs sidebar, yet most specs treat both as afterthoughts. Duplicate ids, verb-first names, and a unique tag per endpoint produce unusable clients and a wall of operations. Here is a naming system...
Which JSON Schema keywords become types, which are enforced at runtime, and which are only annotations? Here is how format, pattern, ranges, required, and nullability flow into codegen, validators, mocks, and AI-generated test data.
