Struct ClientCapabilitiesBuilder 

pub struct ClientCapabilitiesBuilder<S = ClientCapabilitiesBuilderState> { /* private fields */ }

Const-generic ClientCapabilities builder with compile-time validation

This builder ensures that capability-specific methods are only available when the corresponding capability is enabled, providing compile-time safety with comprehensive compile-time validation.

Implementations

impl ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<true, true, true, true>>

pub fn new() -> Self

Create a new ClientCapabilities builder with all capabilities enabled (opt-out model)

By default, all capabilities are enabled. Use .without_*() methods to disable specific capabilities if needed.

This design provides forward compatibility - when new MCP capabilities are added, existing clients automatically support them without code changes.

For clients that need explicit opt-in behavior, use ClientCapabilitiesBuilder::minimal().

impl ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<false, false, false, false>>

pub fn minimal() -> Self

Create a minimal ClientCapabilities builder with no capabilities enabled (opt-in model)

Starts with all capabilities disabled. Use .enable_*() methods to opt-in to specific capabilities.

Most users should use ClientCapabilitiesBuilder::new() instead, which provides an opt-out model with all capabilities enabled by default.

Use this constructor when:

• You need explicit control over which capabilities are enabled
• You’re building a restricted client (embedded, CLI-only, etc.)
• You want to minimize the attack surface

impl<S> ClientCapabilitiesBuilder<S>

pub fn build(self) -> ClientCapabilities

Build the final ClientCapabilities

Consumes the builder and returns the configured ClientCapabilities. All compile-time validations have been enforced during building.

pub fn with_strict_validation(self) -> Self

TurboMCP Extension: Enable strict validation mode

When enabled, the builder will perform additional runtime validations on top of the compile-time guarantees.

pub fn with_negotiator(self, negotiator: CapabilityNegotiator) -> Self

TurboMCP Extension: Set capability negotiator

Integrates with TurboMCP’s sophisticated capability negotiation system for advanced client-server capability matching.

pub fn validate(&self) -> Result<(), String>

TurboMCP Extension: Validate capability configuration

Performs additional runtime validation to ensure the capability configuration makes sense in the current context.

pub fn summary(&self) -> String

Get a summary of enabled capabilities

Returns a human-readable summary of which capabilities are enabled.

impl<const R: bool, const S: bool, const E: bool> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<false, R, S, E>>

pub fn enable_experimental( self, ) -> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<true, R, S, E>>

Enable experimental capabilities

Transitions the builder to a state where experimental capability methods become available at compile time.

pub fn enable_experimental_with( self, experimental: HashMap<String, Value>, ) -> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<true, R, S, E>>

Enable experimental capabilities with specific values

impl<const X: bool, const S: bool, const E: bool> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<X, false, S, E>>

pub fn enable_roots( self, ) -> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<X, true, S, E>>

Enable roots capabilities

impl<const X: bool, const R: bool, const E: bool> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<X, R, false, E>>

pub fn enable_sampling( self, ) -> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<X, R, true, E>>

Enable sampling capabilities

impl<const X: bool, const R: bool, const S: bool> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<X, R, S, false>>

pub fn enable_elicitation( self, ) -> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<X, R, S, true>>

Enable elicitation capabilities

pub fn enable_elicitation_with_schema_validation( self, ) -> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<X, R, S, true>>

Enable elicitation with schema validation

impl<const X: bool, const S: bool, const E: bool> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<X, true, S, E>>

pub fn enable_roots_list_changed(self) -> Self

Enable roots list changed notifications

This method is only available when roots capabilities are enabled, providing compile-time safety.

impl<const R: bool, const S: bool, const E: bool> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<true, R, S, E>>

pub fn without_experimental( self, ) -> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<false, R, S, E>>

Disable experimental capabilities (opt-out)

Transitions the builder to a state where experimental capability methods are no longer available at compile time.

impl<const X: bool, const S: bool, const E: bool> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<X, true, S, E>>

pub fn without_roots( self, ) -> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<X, false, S, E>>

Disable roots capabilities (opt-out)

Transitions the builder to a state where roots capability methods are no longer available at compile time.

impl<const X: bool, const R: bool, const E: bool> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<X, R, true, E>>

pub fn without_sampling( self, ) -> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<X, R, false, E>>

Disable sampling capabilities (opt-out)

Transitions the builder to a state where sampling capability methods are no longer available at compile time.

impl<const X: bool, const R: bool, const S: bool> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<X, R, S, true>>

pub fn without_elicitation( self, ) -> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<X, R, S, false>>

Disable elicitation capabilities (opt-out)

Transitions the builder to a state where elicitation capability methods are no longer available at compile time.

impl<const R: bool, const S: bool, const E: bool> ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<true, R, S, E>>

pub fn add_experimental_capability<K, V>(self, key: K, value: V) -> Self

where K: Into<String>, V: Into<Value>,

Add experimental capability

This method is only available when experimental capabilities are enabled.

Trait Implementations

impl<S: Clone> Clone for ClientCapabilitiesBuilder<S>

fn clone(&self) -> ClientCapabilitiesBuilder<S>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<S: Debug> Debug for ClientCapabilitiesBuilder<S>

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

Formats the value using the given formatter.

impl Default for ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<true, true, true, true>>

fn default() -> Self

Returns the “default value” for a type.