Struct ClientCapabilities 

pub struct ClientCapabilities {
    pub roots: Option<RootsCapability>,
    pub sampling: Option<SamplingCapability>,
    pub elicitation: Option<ElicitationCapability>,
    pub tasks: Option<TasksCapability>,
    pub experimental: Option<Value>,
}

Client capabilities advertised during initialization.

Fields

roots: Option<RootsCapability>

Roots (file system access) capabilities.

sampling: Option<SamplingCapability>

Sampling capabilities.

elicitation: Option<ElicitationCapability>

Elicitation capabilities.

tasks: Option<TasksCapability>

Task capabilities (2025-11-25): which client-handled requests accept task augmentation.

experimental: Option<Value>

Experimental capabilities.

Implementations

impl ClientCapabilities

pub fn new() -> Self

Create empty capabilities.

pub fn with_roots(self) -> Self

Enable roots support.

pub const fn with_roots_and_changes(self) -> Self

Enable roots support with change notifications.

pub fn with_sampling(self) -> Self

Enable sampling support.

Not const: SamplingCapability now holds Option<serde_json::Value> sub-capabilities, whose destructor is not const-evaluable.

pub fn with_sampling_tools(self) -> Self

Enable sampling with tool-use support (declares sampling.tools).

pub fn with_sampling_context(self) -> Self

Enable sampling with context-inclusion support (declares sampling.context).

pub fn with_elicitation(self) -> Self

Enable elicitation support (form mode).

This declares elicitation: {}, which is form-capable (the 2025-06-18 behaviour). Use with_url_elicitation to additionally declare URL-mode support.

pub fn with_form_elicitation(self) -> Self

Declare form-mode elicitation support explicitly (elicitation.form).

pub fn with_url_elicitation(self) -> Self

Declare URL-mode elicitation support (elicitation.url).

pub fn with_tasks(self) -> Self

Enable task support (tasks/list and tasks/cancel).

This declares the base task operations only; declare which requests accept task augmentation via with_task_sampling.

pub fn with_task_sampling(self) -> Self

Declare task-augmented sampling/createMessage support (tasks.requests.sampling.createMessage).

Declare plain sampling support separately via with_sampling.

pub fn has_task_sampling(&self) -> bool

Check if task-augmented sampling/createMessage is declared.

pub fn has_form_elicitation(&self) -> bool

Check if form-mode elicitation is supported.

True when elicitation.form is declared, or when elicitation is present but empty ({}), which is form-capable for backwards compatibility.

pub fn has_url_elicitation(&self) -> bool

Check if URL-mode elicitation is supported (elicitation.url declared).

pub const fn has_roots(&self) -> bool

Check if roots are supported.

pub const fn has_sampling(&self) -> bool

Check if sampling is supported.

pub const fn has_sampling_tools(&self) -> bool

Whether the client declared tool-use support in sampling (sampling.tools).

pub const fn has_sampling_context(&self) -> bool

Whether the client declared context-inclusion support in sampling (sampling.context).

pub const fn has_elicitation(&self) -> bool

Check if elicitation is supported.

pub fn with_extensions(self, registry: ExtensionRegistry) -> Self

Set extensions from an extension registry.

This populates the experimental field with extension declarations.

pub fn has_extension(&self, name: &str) -> bool

Check if a specific extension is supported.

pub fn extensions(&self) -> Option<ExtensionRegistry>

Get the extension registry from capabilities.

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

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<Self, __D::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::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.