Struct ClientCapabilities 

pub struct ClientCapabilities {
    pub roots: Option<RootsCapability>,
    pub sampling: Option<SamplingCapability>,
    pub elicitation: Option<ElicitationCapability>,
    pub tasks: Option<ClientTasksCapability>,
    pub experimental: Option<HashMap<String, Value>>,
    pub extensions: Option<HashMap<String, Value>>,
}

Features a client can provide or accept.

For protocol 2026-07-28 this value is carried in request _meta; earlier versions send it once in InitializeParams. An absent capability means the client does not advertise support for that feature.

Fields

roots: Option<RootsCapability>

Support for server requests that list filesystem roots.

sampling: Option<SamplingCapability>

Support for server-initiated model sampling.

elicitation: Option<ElicitationCapability>

Support for server-initiated user elicitation.

tasks: Option<ClientTasksCapability>

Support for the legacy client-side task capability shape.

experimental: Option<HashMap<String, Value>>

Experimental, non-standard capabilities

extensions: Option<HashMap<String, Value>>

Declared extension support (SEP-1724/SEP-2133).

Keys MUST follow the _meta key naming rules (reverse-DNS prefix mandatory, e.g. io.modelcontextprotocol/tasks) per the final 2026-07-28 schema.

Trait Implementations

impl Clone for ClientCapabilities

fn clone(&self) -> ClientCapabilities

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ClientCapabilities

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

Formats the value using the given formatter.

impl Default for ClientCapabilities

fn default() -> ClientCapabilities

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ClientCapabilities

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for ClientCapabilities

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.