Enum ContentType 

pub enum ContentType {
    Json,
    Yaml,
    Cbor,
    MsgPack,
    Csv,
    Proto,
    FormUrlEncoded,
    MultipartForm,
    Sse,
    WebSocket,
    GrpcWeb,
    OpenApi,
    Mcp,
    Markdown,
}

Supported content types, transports, and discovery formats.

Copy, stack-allocated, zero-cost to pass around.

Variants

Json

JSON (application/json) — default

Yaml

YAML (application/yaml)

Cbor

CBOR (application/cbor) — binary

MsgPack

MessagePack (application/msgpack) — binary

Csv

CSV (text/csv) — tabular

Proto

Protobuf (application/proto) — binary, also Connect/gRPC

FormUrlEncoded

Form URL-encoded (application/x-www-form-urlencoded) — request deserialization

MultipartForm

Multipart form data (multipart/form-data) — request deserialization

Sse

Server-Sent Events (text/event-stream)

WebSocket

WebSocket (Upgrade: websocket)

GrpcWeb

gRPC-Web / Connect server-streaming (application/grpc-web+json). Length-prefixed envelope frames [flag:u8][len:u32 BE][payload] over a held-open HTTP/2 response — the browser-reachable member of the gRPC family (raw gRPC needs HTTP/2 trailers the fetch API can’t read). Shares the subscribe path with Self::Sse; only the frame encoding differs.

OpenApi

OpenAPI 3.1 spec

Mcp

MCP tools/list response

Markdown

Human-readable Markdown

Implementations

impl ContentType

pub fn from_extension(ext: &str) -> Option<Self>

Parse from URL file extension.

pub fn from_content_type_header(header: &str) -> Option<Self>

Parse from Content-Type request header for transport/format detection.

Returns None for standard types that don’t need special routing.

pub fn from_accept_header(accept: Option<&str>) -> Self

Parse from Accept header value. Falls back to Json.

pub fn from_query_param(query: &str) -> Option<Self>

Parse from ?format= query parameter.

pub const fn header_value(self) -> &'static str

Content-Type header value for the response.

pub const fn is_streaming(self) -> bool

Whether this is a streaming transport (SSE, WebSocket, gRPC-Web).

pub const fn is_streaming_subscribe(self) -> bool

Whether this is a server-to-client streaming-subscribe transport (SSE or gRPC-Web) — the formats the subscribe handler serves over a held-open response. Excludes WebSocket (handled by an upgrade in the host layer before dispatch).

pub const fn is_data_format(self) -> bool

Whether this is a data serialization format.

Trait Implementations

impl Clone for ContentType

fn clone(&self) -> ContentType

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for ContentType

impl Debug for ContentType

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ContentType

fn default() -> ContentType

Returns the “default value” for a type.

impl Eq for ContentType

impl Hash for ContentType

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ContentType

fn eq(&self, other: &ContentType) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for ContentType