Errors, uploads, and endpoint patterns

These endpoint patterns share the contract boundary but solve different problems. Read only the page required by the operation:

• Expected errors and HTTP mapping covers one typed domain-error family, declared status/code pairs, adapter mapping, and browser parsing.
• Multipart file uploads covers contract declaration, the handler files argument, row-safe target checks, file limits, and multipart exercise.
• Non-JSON and raw responses covers typed text/CSV responses and the narrow cases that require a raw Response.

The shared contract owns the wire shape. The route adapter owns request parsing and HTTP translation. Domain code owns invariants. Unexpected failures remain on the application’s central error path.

Related documentation

• Shared contracts and request validation
• Custom API endpoints
• Contract helpers and wire types