Route Definition API

Contract endpoints are built with the Define factory and a fluent builder. Roslyn reads the chain at generation time; the same object binds transport input and constructs contract-owned responses at runtime.

Factories

Factory	Variants	Default success status
Define.Get(route)	untyped, <TOutput>, <TInput, TOutput>	200
Define.Post(route)	untyped, <TOutput>, <TInput, TOutput>	201
Define.Put(route) / Define.Patch(route)	untyped, <TOutput>, <TInput, TOutput>	200
Define.Delete(route)	untyped, <TOutput>, <TInput, TOutput>	204 untyped, 200 typed (204-with-body is invalid HTTP)
Define.File(route)	untyped, <TInput>	200, GET, application/octet-stream

An untyped definition can become input-only via .Accepts<TInput>() (e.g. a PUT that takes a body and returns 204).

Builder methods

All return the definition for chaining.

Method	Effect
.Summary(text) / .Description(text)	OpenAPI summary / description
.Status(code)	Override the success status. May only be called once.
.Returns<T>(status[, description])	Declare an additional typed response (errors, alternates). Each status may be declared once.
.Returns(status[, description])	Same, without a payload type.
.WithResponseHeader<T>(status, name[, description][, required:])	Declare a typed response header on a status (responses[status].headers). The non-generic overload declares a string header; required is an explicit opt-in promise. Spec-only — Rivet never sets or validates it; emitting the header is handler code. Each (status, name) pair may be declared once.
.WithResponseHeader<T>(name[, description][, required:])	Same, targeting the endpoint's success status; omit <T> for a string header.
.Secure(scheme)	Reference a security scheme by name (define it with --security).
.Anonymous()	No auth required (security: []).
.QueryAuth(name = "token")	Auth token as a required query parameter — for media players that cannot set headers. Emits x-rivet-query-auth.
.FormEncoded()	Request body is application/x-www-form-urlencoded.
.AcceptsFile()	Request body is multipart/form-data with a binary file part.
.AcceptsBinary(contentType = "application/octet-stream")	Request body is the raw bytes (type: string, format: binary). Spec-only — host code reads the stream; TInput properties lower to route/query params instead of a JSON body. Mutually exclusive with .AcceptsFile() / .FormEncoded().
.ProducesFile(contentType = "application/octet-stream")	Response is a binary download.
.ContentType(mediaType)	FileRouteDefinition alias for ProducesFile.
.AcceptsContentType(mediaType)	Declared media type for a non-JSON request body (e.g. "text/plain" for a string body). The body SCHEMA is unchanged — only the content-type key. Spec-only. Mutually exclusive with .FormEncoded() / .AcceptsBinary().
.ProducesContentType(mediaType)	Declared media type for a non-JSON success response (e.g. "text/html"). Schema unchanged; error responses stay application/json. Spec-only. Mutually exclusive with .ProducesFile().
.RequestExampleJson(json, ...) / .ResponseExampleJson(status, json, ...)	Attach examples. Runtime no-ops — read by Roslyn only. The ...Ref variants reference component examples.

Runtime responses

• Input-bearing definitions use .Bind(input) first. It accepts the declared TInput and returns a bound endpoint retaining the declared output contract. Definitions without input use the terminal methods directly.
• .Success(payload) constructs the declared success response; void definitions use .Success(). The payload must match the declared TOutput.
• .Error(status, payload) selects a typed response declared with .Returns<T>(); .Error(status) selects a declared bodyless response. Undeclared statuses and payload mismatches throw RivetContractViolationException.
• .File(content, ...) constructs a declared binary response from byte[], Stream, or an absolute physical path. It carries the contract content type and optional download name, range processing, last-modified value, and entity tag.
• All terminals return RivetResult. Use the first-party .ToActionResult() for MVC or .ToResult() for minimal APIs at the host boundary. Application execution remains ordinary C# outside the contract response API.

See Runtime Validation for the exact enforcement scope and RivetContractViolationHandler for the structured failure envelope.

Immutability

Definitions are published on the first Bind, Success, Error, or File; after that every builder mutator throws. Configure the definition fully in its static readonly initializer.