Struct DiscoverResult 

pub struct DiscoverResult {
    pub supported_versions: Vec<String>,
    pub capabilities: ServerCapabilities,
    pub ttl_ms: Option<u64>,
    pub cache_scope: Option<CacheScope>,
    pub instructions: Option<String>,
    pub meta: Option<ResultMeta>,
}

Result of the server/discover RPC (SEP-2575).

Shape mirrors InitializeResult with the singular protocol_version replaced by supported_versions – a server/discover call is version-independent, so the server enumerates every version it can speak and the client picks.

The final 2026-07-28 schema dropped the serverInfo body field (server identity now lives in _meta["io.modelcontextprotocol/serverInfo"], via ResultMeta) and made this a CacheableResult-shaped type (the spec’s name for the interface; this crate has no such Rust type – each cacheable result inlines its own ttl_ms/cache_scope fields). This crate keeps ttl_ms/cache_scope as Option rather than the spec’s required number/string – the same “None means no opinion” convention used by every other cacheable result in this file (see CacheScope) – rather than a one-off required-field type here.

Fields

supported_versions: Vec<String>

All protocol versions this server can speak. The client picks one and signals it via MCP-Protocol-Version on subsequent requests.

capabilities: ServerCapabilities

Server capabilities (same shape as the initialize result).

ttl_ms: Option<u64>

SEP-2549: client-cache TTL in milliseconds for this response. None means “no opinion – client policy decides”.

cache_scope: Option<CacheScope>

SEP-2549: scope the cached result applies to. None means scope is unspecified.

instructions: Option<String>

Optional instructions describing how to use this server.

meta: Option<ResultMeta>

Protocol-level metadata. Carries server identity (io.modelcontextprotocol/serverInfo) per SEP-2575.

Trait Implementations

impl Clone for DiscoverResult

fn clone(&self) -> DiscoverResult

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DiscoverResult

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

Formats the value using the given formatter.

impl Default for DiscoverResult

fn default() -> DiscoverResult

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for DiscoverResult

fn deserialize<__D>( __deserializer: __D, ) -> Result<DiscoverResult, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for DiscoverResult

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.