Contract before runtime
Public behavior is specified before it becomes a convenience of one server framework or generated client.
HTTPAPI
A shared contract for typed HTTP services.
01
The project
HTTPAPI defines the behavior of a typed HTTP service independently of the language or framework used to implement it. The contract covers routing, request metadata, response envelopes, projections and structured errors.
The Go package is the reference implementation, not the boundary of the idea. The published specification exists so another runtime can implement the same observable semantics and interoperate without copying Go internals.
02
What it owns
Selective responses
Callers can request valid projections while handlers avoid computing response properties that will not be returned.
Errors with meaning
Parsing, validation and application failures have stable machine-readable identities instead of ad hoc response bodies.