feat: Add MCP Elicitation support

crates/rmcp/Cargo.toml

@@ -79,6 +79,7 @@ default = ["base64", "macros", "server"]
 client = ["dep:tokio-stream"]
 server = ["transport-async-rw", "dep:schemars"]
 macros = ["dep:rmcp-macros", "dep:paste"]
+elicitation = []
 
 # reqwest http client
 __reqwest = ["dep:reqwest"]
@@ -201,3 +202,8 @@ path = "tests/test_message_schema.rs"
 name = "test_progress_subscriber"
 required-features = ["server", "client", "macros"]
 path = "tests/test_progress_subscriber.rs"
+
+[[test]]
+name = "test_elicitation"
+required-features = ["elicitation", "client", "server"]
+path = "tests/test_elicitation.rs"

crates/rmcp/src/handler/client.rs

@@ -21,6 +21,10 @@ impl<H: ClientHandler> Service<RoleClient> for H {
  .list_roots(context)
  .await
  .map(ClientResult::ListRootsResult),
+ ServerRequest::CreateElicitationRequest(request) => self
+ .create_elicitation(request.params, context)
+ .await
+ .map(ClientResult::CreateElicitationResult),
  }
  }
 
@@ -86,6 +90,35 @@ pub trait ClientHandler: Sized + Send + Sync + 'static {
  std::future::ready(Ok(ListRootsResult::default()))
  }
 
+ /// Handle an elicitation request from a server asking for user input.
+ ///
+ /// This method is called when a server needs interactive input from the user
+ /// during tool execution. Implementations should present the message to the user,
+ /// collect their input according to the requested schema, and return the result.
+ ///
+ /// # Arguments
+ /// * `request` - The elicitation request with message and schema
+ /// * `context` - The request context
+ ///
+ /// # Returns
+ /// The user's response including action (accept/decline/cancel) and optional data
+ ///
+ /// # Default Behavior
+ /// The default implementation automatically declines all elicitation requests.
+ /// Real clients should override this to provide user interaction.
+ fn create_elicitation(
+ &self,
+ request: CreateElicitationRequestParam,
+ context: RequestContext<RoleClient>,
+ ) -> impl Future<Output = Result<CreateElicitationResult, McpError>> + Send + '_ {
+ // Default implementation declines all requests - real clients should override this
+ let _ = (request, context);
+ std::future::ready(Ok(CreateElicitationResult {
+ action: ElicitationAction::Decline,
+ content: None,
+ }))
+ }
+
  fn on_cancelled(
  &self,
  params: CancelledNotificationParam,

crates/rmcp/src/model.rs

@@ -143,6 +143,7 @@ impl std::fmt::Display for ProtocolVersion {
 }
 
 impl ProtocolVersion {
+ pub const V_2025_06_18: Self = Self(Cow::Borrowed("2025-06-18"));
  pub const V_2025_03_26: Self = Self(Cow::Borrowed("2025-03-26"));
  pub const V_2024_11_05: Self = Self(Cow::Borrowed("2024-11-05"));
  pub const LATEST: Self = Self::V_2025_03_26;
@@ -167,6 +168,7 @@ impl<'de> Deserialize<'de> for ProtocolVersion {
  match s.as_str() {
  "2024-11-05" => return Ok(ProtocolVersion::V_2024_11_05),
  "2025-03-26" => return Ok(ProtocolVersion::V_2025_03_26),
+ "2025-06-18" => return Ok(ProtocolVersion::V_2025_06_18),
  _ => {}
  }
  Ok(ProtocolVersion(Cow::Owned(s)))
@@ -1173,6 +1175,75 @@ pub struct ListRootsResult {
 const_string!(RootsListChangedNotificationMethod = "notifications/roots/list_changed");
 pub type RootsListChangedNotification = NotificationNoParam<RootsListChangedNotificationMethod>;
 
+// =============================================================================
+// ELICITATION (INTERACTIVE USER INPUT)
+// =============================================================================
+
+// Method constants for elicitation operations.
+// Elicitation allows servers to request interactive input from users during tool execution.
+const_string!(ElicitationCreateRequestMethod = "elicitation/create");
+const_string!(ElicitationResponseNotificationMethod = "notifications/elicitation/response");
+
+/// Represents the possible actions a user can take in response to an elicitation request.
+///
+/// When a server requests user input through elicitation, the user can:
+/// - Accept: Provide the requested information and continue
+/// - Decline: Refuse to provide the information but continue the operation
+/// - Cancel: Stop the entire operation
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[serde(rename_all = "lowercase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub enum ElicitationAction {
+ /// User accepts the request and provides the requested information
+ Accept,
+ /// User declines to provide the information but allows the operation to continue
+ Decline,
+ /// User cancels the entire operation
+ Cancel,
+}
+
+/// Parameters for creating an elicitation request to gather user input.
+///
+/// This structure contains everything needed to request interactive input from a user:
+/// - A human-readable message explaining what information is needed
+/// - A JSON schema defining the expected structure of the response
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct CreateElicitationRequestParam {
+ /// Human-readable message explaining what input is needed from the user.
+ /// This should be clear and provide sufficient context for the user to understand
+ /// what information they need to provide.
+ pub message: String,
+
+ /// JSON Schema defining the expected structure and validation rules for the user's response.
+ /// This allows clients to validate input and provide appropriate UI controls.
+ /// Must be a valid JSON Schema Draft 2020-12 object.
+ pub requested_schema: JsonObject,
+}
+
+/// The result returned by a client in response to an elicitation request.
+///
+/// Contains the user's decision (accept/decline/cancel) and optionally their input data
+/// if they chose to accept the request.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct CreateElicitationResult {
+ /// The user's decision on how to handle the elicitation request
+ pub action: ElicitationAction,
+
+ /// The actual data provided by the user, if they accepted the request.
+ /// Must conform to the JSON schema specified in the original request.
+ /// Only present when action is Accept.
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub content: Option<Value>,
+}
+
+/// Request type for creating an elicitation to gather user input
+pub type CreateElicitationRequest =
+ Request<ElicitationCreateRequestMethod, CreateElicitationRequestParam>;
+
 // =============================================================================
 // TOOL EXECUTION RESULTS
 // =============================================================================
@@ -1430,7 +1501,7 @@ ts_union!(
 );
 
 ts_union!(
- export type ClientResult = CreateMessageResult | ListRootsResult | EmptyResult;
+ export type ClientResult = CreateMessageResult | ListRootsResult | CreateElicitationResult | EmptyResult;
 );
 
 impl ClientResult {
@@ -1445,7 +1516,8 @@ ts_union!(
  export type ServerRequest =
  | PingRequest
  | CreateMessageRequest
- | ListRootsRequest;
+ | ListRootsRequest
+ | CreateElicitationRequest;
 );
 
 ts_union!(
@@ -1470,6 +1542,7 @@ ts_union!(
  | ReadResourceResult
  | CallToolResult
  | ListToolsResult
+ | CreateElicitationResult
  | EmptyResult
  ;
 );

crates/rmcp/src/model/capabilities.rs

@@ -40,6 +40,22 @@ pub struct RootsCapabilities {
  pub list_changed: Option<bool>,
 }
 
+/// Capability for handling elicitation requests from servers.
+///
+/// Elicitation allows servers to request interactive input from users during tool execution.
+/// This capability indicates that a client can handle elicitation requests and present
+/// appropriate UI to users for collecting the requested information.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Default)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct ElicitationCapability {
+ /// Whether the client supports JSON Schema validation for elicitation responses.
+ /// When true, the client will validate user input against the requested_schema
+ /// before sending the response back to the server.
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub schema_validation: Option<bool>,
+}
+
 ///
 /// # Builder
 /// ```rust
@@ -59,6 +75,9 @@ pub struct ClientCapabilities {
  pub roots: Option<RootsCapabilities>,
  #[serde(skip_serializing_if = "Option::is_none")]
  pub sampling: Option<JsonObject>,
+ /// Capability to handle elicitation requests from servers for interactive user input
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub elicitation: Option<ElicitationCapability>,
 }
 
 ///
@@ -253,6 +272,7 @@ builder! {
  experimental: ExperimentalCapabilities,
  roots: RootsCapabilities,
  sampling: JsonObject,
+ elicitation: ElicitationCapability,
  }
 }
 
@@ -267,6 +287,21 @@ impl<const E: bool, const S: bool>
  }
 }
 
+#[cfg(feature = "elicitation")]
+impl<const E: bool, const R: bool, const S: bool>
+ ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<E, R, S, true>>
+{
+ /// Enable JSON Schema validation for elicitation responses.
+ /// When enabled, the client will validate user input against the requested_schema
+ /// before sending responses back to the server.
+ pub fn enable_elicitation_schema_validation(mut self) -> Self {
+ if let Some(c) = self.elicitation.as_mut() {
+ c.schema_validation = Some(true);
+ }
+ self
+ }
+}
+
 #[cfg(test)]
 mod test {
  use super::*;

crates/rmcp/src/model/meta.rs

@@ -74,6 +74,7 @@ variant_extension! {
  PingRequest
  CreateMessageRequest
  ListRootsRequest
+ CreateElicitationRequest
  }
 }
 

crates/rmcp/Cargo.toml

@@ -79,6 +79,7 @@ default = ["base64", "macros", "server"]
 client = ["dep:tokio-stream"]
 server = ["transport-async-rw", "dep:schemars"]
 macros = ["dep:rmcp-macros", "dep:paste"]
+elicitation = []
 
 # reqwest http client
 __reqwest = ["dep:reqwest"]
@@ -201,3 +202,8 @@ path = "tests/test_message_schema.rs"
 name = "test_progress_subscriber"
 required-features = ["server", "client", "macros"]
 path = "tests/test_progress_subscriber.rs"
+
+[[test]]
+name = "test_elicitation"
+required-features = ["elicitation", "client", "server"]
+path = "tests/test_elicitation.rs"

crates/rmcp/src/handler/client.rs

@@ -21,6 +21,10 @@ impl<H: ClientHandler> Service<RoleClient> for H {
  .list_roots(context)
  .await
  .map(ClientResult::ListRootsResult),
+ ServerRequest::CreateElicitationRequest(request) => self
+ .create_elicitation(request.params, context)
+ .await
+ .map(ClientResult::CreateElicitationResult),
  }
  }
 
@@ -86,6 +90,35 @@ pub trait ClientHandler: Sized + Send + Sync + 'static {
  std::future::ready(Ok(ListRootsResult::default()))
  }
 
+ /// Handle an elicitation request from a server asking for user input.
+ ///
+ /// This method is called when a server needs interactive input from the user
+ /// during tool execution. Implementations should present the message to the user,
+ /// collect their input according to the requested schema, and return the result.
+ ///
+ /// # Arguments
+ /// * `request` - The elicitation request with message and schema
+ /// * `context` - The request context
+ ///
+ /// # Returns
+ /// The user's response including action (accept/decline/cancel) and optional data
+ ///
+ /// # Default Behavior
+ /// The default implementation automatically declines all elicitation requests.
+ /// Real clients should override this to provide user interaction.
+ fn create_elicitation(
+ &self,
+ request: CreateElicitationRequestParam,
+ context: RequestContext<RoleClient>,
+ ) -> impl Future<Output = Result<CreateElicitationResult, McpError>> + Send + '_ {
+ // Default implementation declines all requests - real clients should override this
+ let _ = (request, context);
+ std::future::ready(Ok(CreateElicitationResult {
+ action: ElicitationAction::Decline,
+ content: None,
+ }))
+ }
+
  fn on_cancelled(
  &self,
  params: CancelledNotificationParam,

crates/rmcp/src/model.rs

@@ -143,6 +143,7 @@ impl std::fmt::Display for ProtocolVersion {
 }
 
 impl ProtocolVersion {
+ pub const V_2025_06_18: Self = Self(Cow::Borrowed("2025-06-18"));
  pub const V_2025_03_26: Self = Self(Cow::Borrowed("2025-03-26"));
  pub const V_2024_11_05: Self = Self(Cow::Borrowed("2024-11-05"));
  pub const LATEST: Self = Self::V_2025_03_26;
@@ -167,6 +168,7 @@ impl<'de> Deserialize<'de> for ProtocolVersion {
  match s.as_str() {
  "2024-11-05" => return Ok(ProtocolVersion::V_2024_11_05),
  "2025-03-26" => return Ok(ProtocolVersion::V_2025_03_26),
+ "2025-06-18" => return Ok(ProtocolVersion::V_2025_06_18),
  _ => {}
  }
  Ok(ProtocolVersion(Cow::Owned(s)))
@@ -1173,6 +1175,75 @@ pub struct ListRootsResult {
 const_string!(RootsListChangedNotificationMethod = "notifications/roots/list_changed");
 pub type RootsListChangedNotification = NotificationNoParam<RootsListChangedNotificationMethod>;
 
+// =============================================================================
+// ELICITATION (INTERACTIVE USER INPUT)
+// =============================================================================
+
+// Method constants for elicitation operations.
+// Elicitation allows servers to request interactive input from users during tool execution.
+const_string!(ElicitationCreateRequestMethod = "elicitation/create");
+const_string!(ElicitationResponseNotificationMethod = "notifications/elicitation/response");
+
+/// Represents the possible actions a user can take in response to an elicitation request.
+///
+/// When a server requests user input through elicitation, the user can:
+/// - Accept: Provide the requested information and continue
+/// - Decline: Refuse to provide the information but continue the operation
+/// - Cancel: Stop the entire operation
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[serde(rename_all = "lowercase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub enum ElicitationAction {
+ /// User accepts the request and provides the requested information
+ Accept,
+ /// User declines to provide the information but allows the operation to continue
+ Decline,
+ /// User cancels the entire operation
+ Cancel,
+}
+
+/// Parameters for creating an elicitation request to gather user input.
+///
+/// This structure contains everything needed to request interactive input from a user:
+/// - A human-readable message explaining what information is needed
+/// - A JSON schema defining the expected structure of the response
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct CreateElicitationRequestParam {
+ /// Human-readable message explaining what input is needed from the user.
+ /// This should be clear and provide sufficient context for the user to understand
+ /// what information they need to provide.
+ pub message: String,
+
+ /// JSON Schema defining the expected structure and validation rules for the user's response.
+ /// This allows clients to validate input and provide appropriate UI controls.
+ /// Must be a valid JSON Schema Draft 2020-12 object.
+ pub requested_schema: JsonObject,
+}
+
+/// The result returned by a client in response to an elicitation request.
+///
+/// Contains the user's decision (accept/decline/cancel) and optionally their input data
+/// if they chose to accept the request.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct CreateElicitationResult {
+ /// The user's decision on how to handle the elicitation request
+ pub action: ElicitationAction,
+
+ /// The actual data provided by the user, if they accepted the request.
+ /// Must conform to the JSON schema specified in the original request.
+ /// Only present when action is Accept.
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub content: Option<Value>,
+}
+
+/// Request type for creating an elicitation to gather user input
+pub type CreateElicitationRequest =
+ Request<ElicitationCreateRequestMethod, CreateElicitationRequestParam>;
+
 // =============================================================================
 // TOOL EXECUTION RESULTS
 // =============================================================================
@@ -1430,7 +1501,7 @@ ts_union!(
 );
 
 ts_union!(
- export type ClientResult = CreateMessageResult | ListRootsResult | EmptyResult;
+ export type ClientResult = CreateMessageResult | ListRootsResult | CreateElicitationResult | EmptyResult;
 );
 
 impl ClientResult {
@@ -1445,7 +1516,8 @@ ts_union!(
  export type ServerRequest =
  | PingRequest
  | CreateMessageRequest
- | ListRootsRequest;
+ | ListRootsRequest
+ | CreateElicitationRequest;
 );
 
 ts_union!(
@@ -1470,6 +1542,7 @@ ts_union!(
  | ReadResourceResult
  | CallToolResult
  | ListToolsResult
+ | CreateElicitationResult
  | EmptyResult
  ;
 );

crates/rmcp/src/model/capabilities.rs

@@ -40,6 +40,22 @@ pub struct RootsCapabilities {
  pub list_changed: Option<bool>,
 }
 
+/// Capability for handling elicitation requests from servers.
+///
+/// Elicitation allows servers to request interactive input from users during tool execution.
+/// This capability indicates that a client can handle elicitation requests and present
+/// appropriate UI to users for collecting the requested information.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Default)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct ElicitationCapability {
+ /// Whether the client supports JSON Schema validation for elicitation responses.
+ /// When true, the client will validate user input against the requested_schema
+ /// before sending the response back to the server.
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub schema_validation: Option<bool>,
+}
+
 ///
 /// # Builder
 /// ```rust
@@ -59,6 +75,9 @@ pub struct ClientCapabilities {
  pub roots: Option<RootsCapabilities>,
  #[serde(skip_serializing_if = "Option::is_none")]
  pub sampling: Option<JsonObject>,
+ /// Capability to handle elicitation requests from servers for interactive user input
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub elicitation: Option<ElicitationCapability>,
 }
 
 ///
@@ -253,6 +272,7 @@ builder! {
  experimental: ExperimentalCapabilities,
  roots: RootsCapabilities,
  sampling: JsonObject,
+ elicitation: ElicitationCapability,
  }
 }
 
@@ -267,6 +287,21 @@ impl<const E: bool, const S: bool>
  }
 }
 
+#[cfg(feature = "elicitation")]
+impl<const E: bool, const R: bool, const S: bool>
+ ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<E, R, S, true>>
+{
+ /// Enable JSON Schema validation for elicitation responses.
+ /// When enabled, the client will validate user input against the requested_schema
+ /// before sending responses back to the server.
+ pub fn enable_elicitation_schema_validation(mut self) -> Self {
+ if let Some(c) = self.elicitation.as_mut() {
+ c.schema_validation = Some(true);
+ }
+ self
+ }
+}
+
 #[cfg(test)]
 mod test {
  use super::*;

crates/rmcp/src/model/meta.rs

@@ -74,6 +74,7 @@ variant_extension! {
  PingRequest
  CreateMessageRequest
  ListRootsRequest
+ CreateElicitationRequest
  }
 }
 

crates/rmcp/Cargo.toml

@@ -79,6 +79,7 @@ default = ["base64", "macros", "server"]
 client = ["dep:tokio-stream"]
 server = ["transport-async-rw", "dep:schemars"]
 macros = ["dep:rmcp-macros", "dep:paste"]
+elicitation = []
 
 # reqwest http client
 __reqwest = ["dep:reqwest"]
@@ -201,3 +202,8 @@ path = "tests/test_message_schema.rs"
 name = "test_progress_subscriber"
 required-features = ["server", "client", "macros"]
 path = "tests/test_progress_subscriber.rs"
+
+[[test]]
+name = "test_elicitation"
+required-features = ["elicitation", "client", "server"]
+path = "tests/test_elicitation.rs"

crates/rmcp/src/handler/client.rs

@@ -21,6 +21,10 @@ impl<H: ClientHandler> Service<RoleClient> for H {
  .list_roots(context)
  .await
  .map(ClientResult::ListRootsResult),
+ ServerRequest::CreateElicitationRequest(request) => self
+ .create_elicitation(request.params, context)
+ .await
+ .map(ClientResult::CreateElicitationResult),
  }
  }
 
@@ -86,6 +90,35 @@ pub trait ClientHandler: Sized + Send + Sync + 'static {
  std::future::ready(Ok(ListRootsResult::default()))
  }
 
+ /// Handle an elicitation request from a server asking for user input.
+ ///
+ /// This method is called when a server needs interactive input from the user
+ /// during tool execution. Implementations should present the message to the user,
+ /// collect their input according to the requested schema, and return the result.
+ ///
+ /// # Arguments
+ /// * `request` - The elicitation request with message and schema
+ /// * `context` - The request context
+ ///
+ /// # Returns
+ /// The user's response including action (accept/decline/cancel) and optional data
+ ///
+ /// # Default Behavior
+ /// The default implementation automatically declines all elicitation requests.
+ /// Real clients should override this to provide user interaction.
+ fn create_elicitation(
+ &self,
+ request: CreateElicitationRequestParam,
+ context: RequestContext<RoleClient>,
+ ) -> impl Future<Output = Result<CreateElicitationResult, McpError>> + Send + '_ {
+ // Default implementation declines all requests - real clients should override this
+ let _ = (request, context);
+ std::future::ready(Ok(CreateElicitationResult {
+ action: ElicitationAction::Decline,
+ content: None,
+ }))
+ }
+
  fn on_cancelled(
  &self,
  params: CancelledNotificationParam,

crates/rmcp/src/model.rs

@@ -143,6 +143,7 @@ impl std::fmt::Display for ProtocolVersion {
 }
 
 impl ProtocolVersion {
+ pub const V_2025_06_18: Self = Self(Cow::Borrowed("2025-06-18"));
  pub const V_2025_03_26: Self = Self(Cow::Borrowed("2025-03-26"));
  pub const V_2024_11_05: Self = Self(Cow::Borrowed("2024-11-05"));
  pub const LATEST: Self = Self::V_2025_03_26;
@@ -167,6 +168,7 @@ impl<'de> Deserialize<'de> for ProtocolVersion {
  match s.as_str() {
  "2024-11-05" => return Ok(ProtocolVersion::V_2024_11_05),
  "2025-03-26" => return Ok(ProtocolVersion::V_2025_03_26),
+ "2025-06-18" => return Ok(ProtocolVersion::V_2025_06_18),
  _ => {}
  }
  Ok(ProtocolVersion(Cow::Owned(s)))
@@ -1173,6 +1175,75 @@ pub struct ListRootsResult {
 const_string!(RootsListChangedNotificationMethod = "notifications/roots/list_changed");
 pub type RootsListChangedNotification = NotificationNoParam<RootsListChangedNotificationMethod>;
 
+// =============================================================================
+// ELICITATION (INTERACTIVE USER INPUT)
+// =============================================================================
+
+// Method constants for elicitation operations.
+// Elicitation allows servers to request interactive input from users during tool execution.
+const_string!(ElicitationCreateRequestMethod = "elicitation/create");
+const_string!(ElicitationResponseNotificationMethod = "notifications/elicitation/response");
+
+/// Represents the possible actions a user can take in response to an elicitation request.
+///
+/// When a server requests user input through elicitation, the user can:
+/// - Accept: Provide the requested information and continue
+/// - Decline: Refuse to provide the information but continue the operation
+/// - Cancel: Stop the entire operation
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[serde(rename_all = "lowercase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub enum ElicitationAction {
+ /// User accepts the request and provides the requested information
+ Accept,
+ /// User declines to provide the information but allows the operation to continue
+ Decline,
+ /// User cancels the entire operation
+ Cancel,
+}
+
+/// Parameters for creating an elicitation request to gather user input.
+///
+/// This structure contains everything needed to request interactive input from a user:
+/// - A human-readable message explaining what information is needed
+/// - A JSON schema defining the expected structure of the response
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct CreateElicitationRequestParam {
+ /// Human-readable message explaining what input is needed from the user.
+ /// This should be clear and provide sufficient context for the user to understand
+ /// what information they need to provide.
+ pub message: String,
+
+ /// JSON Schema defining the expected structure and validation rules for the user's response.
+ /// This allows clients to validate input and provide appropriate UI controls.
+ /// Must be a valid JSON Schema Draft 2020-12 object.
+ pub requested_schema: JsonObject,
+}
+
+/// The result returned by a client in response to an elicitation request.
+///
+/// Contains the user's decision (accept/decline/cancel) and optionally their input data
+/// if they chose to accept the request.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct CreateElicitationResult {
+ /// The user's decision on how to handle the elicitation request
+ pub action: ElicitationAction,
+
+ /// The actual data provided by the user, if they accepted the request.
+ /// Must conform to the JSON schema specified in the original request.
+ /// Only present when action is Accept.
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub content: Option<Value>,
+}
+
+/// Request type for creating an elicitation to gather user input
+pub type CreateElicitationRequest =
+ Request<ElicitationCreateRequestMethod, CreateElicitationRequestParam>;
+
 // =============================================================================
 // TOOL EXECUTION RESULTS
 // =============================================================================
@@ -1430,7 +1501,7 @@ ts_union!(
 );
 
 ts_union!(
- export type ClientResult = CreateMessageResult | ListRootsResult | EmptyResult;
+ export type ClientResult = CreateMessageResult | ListRootsResult | CreateElicitationResult | EmptyResult;
 );
 
 impl ClientResult {
@@ -1445,7 +1516,8 @@ ts_union!(
  export type ServerRequest =
  | PingRequest
  | CreateMessageRequest
- | ListRootsRequest;
+ | ListRootsRequest
+ | CreateElicitationRequest;
 );
 
 ts_union!(
@@ -1470,6 +1542,7 @@ ts_union!(
  | ReadResourceResult
  | CallToolResult
  | ListToolsResult
+ | CreateElicitationResult
  | EmptyResult
  ;
 );

crates/rmcp/src/model/capabilities.rs

@@ -40,6 +40,22 @@ pub struct RootsCapabilities {
  pub list_changed: Option<bool>,
 }
 
+/// Capability for handling elicitation requests from servers.
+///
+/// Elicitation allows servers to request interactive input from users during tool execution.
+/// This capability indicates that a client can handle elicitation requests and present
+/// appropriate UI to users for collecting the requested information.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Default)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct ElicitationCapability {
+ /// Whether the client supports JSON Schema validation for elicitation responses.
+ /// When true, the client will validate user input against the requested_schema
+ /// before sending the response back to the server.
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub schema_validation: Option<bool>,
+}
+
 ///
 /// # Builder
 /// ```rust
@@ -59,6 +75,9 @@ pub struct ClientCapabilities {
  pub roots: Option<RootsCapabilities>,
  #[serde(skip_serializing_if = "Option::is_none")]
  pub sampling: Option<JsonObject>,
+ /// Capability to handle elicitation requests from servers for interactive user input
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub elicitation: Option<ElicitationCapability>,
 }
 
 ///
@@ -253,6 +272,7 @@ builder! {
  experimental: ExperimentalCapabilities,
  roots: RootsCapabilities,
  sampling: JsonObject,
+ elicitation: ElicitationCapability,
  }
 }
 
@@ -267,6 +287,21 @@ impl<const E: bool, const S: bool>
  }
 }
 
+#[cfg(feature = "elicitation")]
+impl<const E: bool, const R: bool, const S: bool>
+ ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<E, R, S, true>>
+{
+ /// Enable JSON Schema validation for elicitation responses.
+ /// When enabled, the client will validate user input against the requested_schema
+ /// before sending responses back to the server.
+ pub fn enable_elicitation_schema_validation(mut self) -> Self {
+ if let Some(c) = self.elicitation.as_mut() {
+ c.schema_validation = Some(true);
+ }
+ self
+ }
+}
+
 #[cfg(test)]
 mod test {
  use super::*;

crates/rmcp/src/model/meta.rs

@@ -74,6 +74,7 @@ variant_extension! {
  PingRequest
  CreateMessageRequest
  ListRootsRequest
+ CreateElicitationRequest
  }
 }
 

crates/rmcp/Cargo.toml

@@ -79,6 +79,7 @@ default = ["base64", "macros", "server"]
 client = ["dep:tokio-stream"]
 server = ["transport-async-rw", "dep:schemars"]
 macros = ["dep:rmcp-macros", "dep:paste"]
+elicitation = []
 
 # reqwest http client
 __reqwest = ["dep:reqwest"]
@@ -201,3 +202,8 @@ path = "tests/test_message_schema.rs"
 name = "test_progress_subscriber"
 required-features = ["server", "client", "macros"]
 path = "tests/test_progress_subscriber.rs"
+
+[[test]]
+name = "test_elicitation"
+required-features = ["elicitation", "client", "server"]
+path = "tests/test_elicitation.rs"

crates/rmcp/src/handler/client.rs

@@ -21,6 +21,10 @@ impl<H: ClientHandler> Service<RoleClient> for H {
  .list_roots(context)
  .await
  .map(ClientResult::ListRootsResult),
+ ServerRequest::CreateElicitationRequest(request) => self
+ .create_elicitation(request.params, context)
+ .await
+ .map(ClientResult::CreateElicitationResult),
  }
  }
 
@@ -86,6 +90,35 @@ pub trait ClientHandler: Sized + Send + Sync + 'static {
  std::future::ready(Ok(ListRootsResult::default()))
  }
 
+ /// Handle an elicitation request from a server asking for user input.
+ ///
+ /// This method is called when a server needs interactive input from the user
+ /// during tool execution. Implementations should present the message to the user,
+ /// collect their input according to the requested schema, and return the result.
+ ///
+ /// # Arguments
+ /// * `request` - The elicitation request with message and schema
+ /// * `context` - The request context
+ ///
+ /// # Returns
+ /// The user's response including action (accept/decline/cancel) and optional data
+ ///
+ /// # Default Behavior
+ /// The default implementation automatically declines all elicitation requests.
+ /// Real clients should override this to provide user interaction.
+ fn create_elicitation(
+ &self,
+ request: CreateElicitationRequestParam,
+ context: RequestContext<RoleClient>,
+ ) -> impl Future<Output = Result<CreateElicitationResult, McpError>> + Send + '_ {
+ // Default implementation declines all requests - real clients should override this
+ let _ = (request, context);
+ std::future::ready(Ok(CreateElicitationResult {
+ action: ElicitationAction::Decline,
+ content: None,
+ }))
+ }
+
  fn on_cancelled(
  &self,
  params: CancelledNotificationParam,

crates/rmcp/src/model.rs

@@ -143,6 +143,7 @@ impl std::fmt::Display for ProtocolVersion {
 }
 
 impl ProtocolVersion {
+ pub const V_2025_06_18: Self = Self(Cow::Borrowed("2025-06-18"));
  pub const V_2025_03_26: Self = Self(Cow::Borrowed("2025-03-26"));
  pub const V_2024_11_05: Self = Self(Cow::Borrowed("2024-11-05"));
  pub const LATEST: Self = Self::V_2025_03_26;
@@ -167,6 +168,7 @@ impl<'de> Deserialize<'de> for ProtocolVersion {
  match s.as_str() {
  "2024-11-05" => return Ok(ProtocolVersion::V_2024_11_05),
  "2025-03-26" => return Ok(ProtocolVersion::V_2025_03_26),
+ "2025-06-18" => return Ok(ProtocolVersion::V_2025_06_18),
  _ => {}
  }
  Ok(ProtocolVersion(Cow::Owned(s)))
@@ -1173,6 +1175,75 @@ pub struct ListRootsResult {
 const_string!(RootsListChangedNotificationMethod = "notifications/roots/list_changed");
 pub type RootsListChangedNotification = NotificationNoParam<RootsListChangedNotificationMethod>;
 
+// =============================================================================
+// ELICITATION (INTERACTIVE USER INPUT)
+// =============================================================================
+
+// Method constants for elicitation operations.
+// Elicitation allows servers to request interactive input from users during tool execution.
+const_string!(ElicitationCreateRequestMethod = "elicitation/create");
+const_string!(ElicitationResponseNotificationMethod = "notifications/elicitation/response");
+
+/// Represents the possible actions a user can take in response to an elicitation request.
+///
+/// When a server requests user input through elicitation, the user can:
+/// - Accept: Provide the requested information and continue
+/// - Decline: Refuse to provide the information but continue the operation
+/// - Cancel: Stop the entire operation
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[serde(rename_all = "lowercase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub enum ElicitationAction {
+ /// User accepts the request and provides the requested information
+ Accept,
+ /// User declines to provide the information but allows the operation to continue
+ Decline,
+ /// User cancels the entire operation
+ Cancel,
+}
+
+/// Parameters for creating an elicitation request to gather user input.
+///
+/// This structure contains everything needed to request interactive input from a user:
+/// - A human-readable message explaining what information is needed
+/// - A JSON schema defining the expected structure of the response
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct CreateElicitationRequestParam {
+ /// Human-readable message explaining what input is needed from the user.
+ /// This should be clear and provide sufficient context for the user to understand
+ /// what information they need to provide.
+ pub message: String,
+
+ /// JSON Schema defining the expected structure and validation rules for the user's response.
+ /// This allows clients to validate input and provide appropriate UI controls.
+ /// Must be a valid JSON Schema Draft 2020-12 object.
+ pub requested_schema: JsonObject,
+}
+
+/// The result returned by a client in response to an elicitation request.
+///
+/// Contains the user's decision (accept/decline/cancel) and optionally their input data
+/// if they chose to accept the request.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct CreateElicitationResult {
+ /// The user's decision on how to handle the elicitation request
+ pub action: ElicitationAction,
+
+ /// The actual data provided by the user, if they accepted the request.
+ /// Must conform to the JSON schema specified in the original request.
+ /// Only present when action is Accept.
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub content: Option<Value>,
+}
+
+/// Request type for creating an elicitation to gather user input
+pub type CreateElicitationRequest =
+ Request<ElicitationCreateRequestMethod, CreateElicitationRequestParam>;
+
 // =============================================================================
 // TOOL EXECUTION RESULTS
 // =============================================================================
@@ -1430,7 +1501,7 @@ ts_union!(
 );
 
 ts_union!(
- export type ClientResult = CreateMessageResult | ListRootsResult | EmptyResult;
+ export type ClientResult = CreateMessageResult | ListRootsResult | CreateElicitationResult | EmptyResult;
 );
 
 impl ClientResult {
@@ -1445,7 +1516,8 @@ ts_union!(
  export type ServerRequest =
  | PingRequest
  | CreateMessageRequest
- | ListRootsRequest;
+ | ListRootsRequest
+ | CreateElicitationRequest;
 );
 
 ts_union!(
@@ -1470,6 +1542,7 @@ ts_union!(
  | ReadResourceResult
  | CallToolResult
  | ListToolsResult
+ | CreateElicitationResult
  | EmptyResult
  ;
 );

crates/rmcp/src/model/capabilities.rs

@@ -40,6 +40,22 @@ pub struct RootsCapabilities {
  pub list_changed: Option<bool>,
 }
 
+/// Capability for handling elicitation requests from servers.
+///
+/// Elicitation allows servers to request interactive input from users during tool execution.
+/// This capability indicates that a client can handle elicitation requests and present
+/// appropriate UI to users for collecting the requested information.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Default)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct ElicitationCapability {
+ /// Whether the client supports JSON Schema validation for elicitation responses.
+ /// When true, the client will validate user input against the requested_schema
+ /// before sending the response back to the server.
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub schema_validation: Option<bool>,
+}
+
 ///
 /// # Builder
 /// ```rust
@@ -59,6 +75,9 @@ pub struct ClientCapabilities {
  pub roots: Option<RootsCapabilities>,
  #[serde(skip_serializing_if = "Option::is_none")]
  pub sampling: Option<JsonObject>,
+ /// Capability to handle elicitation requests from servers for interactive user input
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub elicitation: Option<ElicitationCapability>,
 }
 
 ///
@@ -253,6 +272,7 @@ builder! {
  experimental: ExperimentalCapabilities,
  roots: RootsCapabilities,
  sampling: JsonObject,
+ elicitation: ElicitationCapability,
  }
 }
 
@@ -267,6 +287,21 @@ impl<const E: bool, const S: bool>
  }
 }
 
+#[cfg(feature = "elicitation")]
+impl<const E: bool, const R: bool, const S: bool>
+ ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<E, R, S, true>>
+{
+ /// Enable JSON Schema validation for elicitation responses.
+ /// When enabled, the client will validate user input against the requested_schema
+ /// before sending responses back to the server.
+ pub fn enable_elicitation_schema_validation(mut self) -> Self {
+ if let Some(c) = self.elicitation.as_mut() {
+ c.schema_validation = Some(true);
+ }
+ self
+ }
+}
+
 #[cfg(test)]
 mod test {
  use super::*;

crates/rmcp/src/model/meta.rs

@@ -74,6 +74,7 @@ variant_extension! {
  PingRequest
  CreateMessageRequest
  ListRootsRequest
+ CreateElicitationRequest
  }
 }
 

crates/rmcp/Cargo.toml

@@ -79,6 +79,7 @@ default = ["base64", "macros", "server"]
 client = ["dep:tokio-stream"]
 server = ["transport-async-rw", "dep:schemars"]
 macros = ["dep:rmcp-macros", "dep:paste"]
+elicitation = []
 
 # reqwest http client
 __reqwest = ["dep:reqwest"]
@@ -201,3 +202,8 @@ path = "tests/test_message_schema.rs"
 name = "test_progress_subscriber"
 required-features = ["server", "client", "macros"]
 path = "tests/test_progress_subscriber.rs"
+
+[[test]]
+name = "test_elicitation"
+required-features = ["elicitation", "client", "server"]
+path = "tests/test_elicitation.rs"

crates/rmcp/src/handler/client.rs

@@ -21,6 +21,10 @@ impl<H: ClientHandler> Service<RoleClient> for H {
  .list_roots(context)
  .await
  .map(ClientResult::ListRootsResult),
+ ServerRequest::CreateElicitationRequest(request) => self
+ .create_elicitation(request.params, context)
+ .await
+ .map(ClientResult::CreateElicitationResult),
  }
  }
 
@@ -86,6 +90,35 @@ pub trait ClientHandler: Sized + Send + Sync + 'static {
  std::future::ready(Ok(ListRootsResult::default()))
  }
 
+ /// Handle an elicitation request from a server asking for user input.
+ ///
+ /// This method is called when a server needs interactive input from the user
+ /// during tool execution. Implementations should present the message to the user,
+ /// collect their input according to the requested schema, and return the result.
+ ///
+ /// # Arguments
+ /// * `request` - The elicitation request with message and schema
+ /// * `context` - The request context
+ ///
+ /// # Returns
+ /// The user's response including action (accept/decline/cancel) and optional data
+ ///
+ /// # Default Behavior
+ /// The default implementation automatically declines all elicitation requests.
+ /// Real clients should override this to provide user interaction.
+ fn create_elicitation(
+ &self,
+ request: CreateElicitationRequestParam,
+ context: RequestContext<RoleClient>,
+ ) -> impl Future<Output = Result<CreateElicitationResult, McpError>> + Send + '_ {
+ // Default implementation declines all requests - real clients should override this
+ let _ = (request, context);
+ std::future::ready(Ok(CreateElicitationResult {
+ action: ElicitationAction::Decline,
+ content: None,
+ }))
+ }
+
  fn on_cancelled(
  &self,
  params: CancelledNotificationParam,

crates/rmcp/src/model.rs

@@ -143,6 +143,7 @@ impl std::fmt::Display for ProtocolVersion {
 }
 
 impl ProtocolVersion {
+ pub const V_2025_06_18: Self = Self(Cow::Borrowed("2025-06-18"));
  pub const V_2025_03_26: Self = Self(Cow::Borrowed("2025-03-26"));
  pub const V_2024_11_05: Self = Self(Cow::Borrowed("2024-11-05"));
  pub const LATEST: Self = Self::V_2025_03_26;
@@ -167,6 +168,7 @@ impl<'de> Deserialize<'de> for ProtocolVersion {
  match s.as_str() {
  "2024-11-05" => return Ok(ProtocolVersion::V_2024_11_05),
  "2025-03-26" => return Ok(ProtocolVersion::V_2025_03_26),
+ "2025-06-18" => return Ok(ProtocolVersion::V_2025_06_18),
  _ => {}
  }
  Ok(ProtocolVersion(Cow::Owned(s)))
@@ -1173,6 +1175,75 @@ pub struct ListRootsResult {
 const_string!(RootsListChangedNotificationMethod = "notifications/roots/list_changed");
 pub type RootsListChangedNotification = NotificationNoParam<RootsListChangedNotificationMethod>;
 
+// =============================================================================
+// ELICITATION (INTERACTIVE USER INPUT)
+// =============================================================================
+
+// Method constants for elicitation operations.
+// Elicitation allows servers to request interactive input from users during tool execution.
+const_string!(ElicitationCreateRequestMethod = "elicitation/create");
+const_string!(ElicitationResponseNotificationMethod = "notifications/elicitation/response");
+
+/// Represents the possible actions a user can take in response to an elicitation request.
+///
+/// When a server requests user input through elicitation, the user can:
+/// - Accept: Provide the requested information and continue
+/// - Decline: Refuse to provide the information but continue the operation
+/// - Cancel: Stop the entire operation
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[serde(rename_all = "lowercase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub enum ElicitationAction {
+ /// User accepts the request and provides the requested information
+ Accept,
+ /// User declines to provide the information but allows the operation to continue
+ Decline,
+ /// User cancels the entire operation
+ Cancel,
+}
+
+/// Parameters for creating an elicitation request to gather user input.
+///
+/// This structure contains everything needed to request interactive input from a user:
+/// - A human-readable message explaining what information is needed
+/// - A JSON schema defining the expected structure of the response
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct CreateElicitationRequestParam {
+ /// Human-readable message explaining what input is needed from the user.
+ /// This should be clear and provide sufficient context for the user to understand
+ /// what information they need to provide.
+ pub message: String,
+
+ /// JSON Schema defining the expected structure and validation rules for the user's response.
+ /// This allows clients to validate input and provide appropriate UI controls.
+ /// Must be a valid JSON Schema Draft 2020-12 object.
+ pub requested_schema: JsonObject,
+}
+
+/// The result returned by a client in response to an elicitation request.
+///
+/// Contains the user's decision (accept/decline/cancel) and optionally their input data
+/// if they chose to accept the request.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct CreateElicitationResult {
+ /// The user's decision on how to handle the elicitation request
+ pub action: ElicitationAction,
+
+ /// The actual data provided by the user, if they accepted the request.
+ /// Must conform to the JSON schema specified in the original request.
+ /// Only present when action is Accept.
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub content: Option<Value>,
+}
+
+/// Request type for creating an elicitation to gather user input
+pub type CreateElicitationRequest =
+ Request<ElicitationCreateRequestMethod, CreateElicitationRequestParam>;
+
 // =============================================================================
 // TOOL EXECUTION RESULTS
 // =============================================================================
@@ -1430,7 +1501,7 @@ ts_union!(
 );
 
 ts_union!(
- export type ClientResult = CreateMessageResult | ListRootsResult | EmptyResult;
+ export type ClientResult = CreateMessageResult | ListRootsResult | CreateElicitationResult | EmptyResult;
 );
 
 impl ClientResult {
@@ -1445,7 +1516,8 @@ ts_union!(
  export type ServerRequest =
  | PingRequest
  | CreateMessageRequest
- | ListRootsRequest;
+ | ListRootsRequest
+ | CreateElicitationRequest;
 );
 
 ts_union!(
@@ -1470,6 +1542,7 @@ ts_union!(
  | ReadResourceResult
  | CallToolResult
  | ListToolsResult
+ | CreateElicitationResult
  | EmptyResult
  ;
 );

crates/rmcp/src/model/capabilities.rs

@@ -40,6 +40,22 @@ pub struct RootsCapabilities {
  pub list_changed: Option<bool>,
 }
 
+/// Capability for handling elicitation requests from servers.
+///
+/// Elicitation allows servers to request interactive input from users during tool execution.
+/// This capability indicates that a client can handle elicitation requests and present
+/// appropriate UI to users for collecting the requested information.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Default)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct ElicitationCapability {
+ /// Whether the client supports JSON Schema validation for elicitation responses.
+ /// When true, the client will validate user input against the requested_schema
+ /// before sending the response back to the server.
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub schema_validation: Option<bool>,
+}
+
 ///
 /// # Builder
 /// ```rust
@@ -59,6 +75,9 @@ pub struct ClientCapabilities {
  pub roots: Option<RootsCapabilities>,
  #[serde(skip_serializing_if = "Option::is_none")]
  pub sampling: Option<JsonObject>,
+ /// Capability to handle elicitation requests from servers for interactive user input
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub elicitation: Option<ElicitationCapability>,
 }
 
 ///
@@ -253,6 +272,7 @@ builder! {
  experimental: ExperimentalCapabilities,
  roots: RootsCapabilities,
  sampling: JsonObject,
+ elicitation: ElicitationCapability,
  }
 }
 
@@ -267,6 +287,21 @@ impl<const E: bool, const S: bool>
  }
 }
 
+#[cfg(feature = "elicitation")]
+impl<const E: bool, const R: bool, const S: bool>
+ ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<E, R, S, true>>
+{
+ /// Enable JSON Schema validation for elicitation responses.
+ /// When enabled, the client will validate user input against the requested_schema
+ /// before sending responses back to the server.
+ pub fn enable_elicitation_schema_validation(mut self) -> Self {
+ if let Some(c) = self.elicitation.as_mut() {
+ c.schema_validation = Some(true);
+ }
+ self
+ }
+}
+
 #[cfg(test)]
 mod test {
  use super::*;

crates/rmcp/src/model/meta.rs

@@ -74,6 +74,7 @@ variant_extension! {
  PingRequest
  CreateMessageRequest
  ListRootsRequest
+ CreateElicitationRequest
  }
 }
 

crates/rmcp/Cargo.toml

@@ -79,6 +79,7 @@ default = ["base64", "macros", "server"]
 client = ["dep:tokio-stream"]
 server = ["transport-async-rw", "dep:schemars"]
 macros = ["dep:rmcp-macros", "dep:paste"]
+elicitation = []
 
 # reqwest http client
 __reqwest = ["dep:reqwest"]
@@ -201,3 +202,8 @@ path = "tests/test_message_schema.rs"
 name = "test_progress_subscriber"
 required-features = ["server", "client", "macros"]
 path = "tests/test_progress_subscriber.rs"
+
+[[test]]
+name = "test_elicitation"
+required-features = ["elicitation", "client", "server"]
+path = "tests/test_elicitation.rs"

crates/rmcp/src/handler/client.rs

@@ -21,6 +21,10 @@ impl<H: ClientHandler> Service<RoleClient> for H {
  .list_roots(context)
  .await
  .map(ClientResult::ListRootsResult),
+ ServerRequest::CreateElicitationRequest(request) => self
+ .create_elicitation(request.params, context)
+ .await
+ .map(ClientResult::CreateElicitationResult),
  }
  }
 
@@ -86,6 +90,35 @@ pub trait ClientHandler: Sized + Send + Sync + 'static {
  std::future::ready(Ok(ListRootsResult::default()))
  }
 
+ /// Handle an elicitation request from a server asking for user input.
+ ///
+ /// This method is called when a server needs interactive input from the user
+ /// during tool execution. Implementations should present the message to the user,
+ /// collect their input according to the requested schema, and return the result.
+ ///
+ /// # Arguments
+ /// * `request` - The elicitation request with message and schema
+ /// * `context` - The request context
+ ///
+ /// # Returns
+ /// The user's response including action (accept/decline/cancel) and optional data
+ ///
+ /// # Default Behavior
+ /// The default implementation automatically declines all elicitation requests.
+ /// Real clients should override this to provide user interaction.
+ fn create_elicitation(
+ &self,
+ request: CreateElicitationRequestParam,
+ context: RequestContext<RoleClient>,
+ ) -> impl Future<Output = Result<CreateElicitationResult, McpError>> + Send + '_ {
+ // Default implementation declines all requests - real clients should override this
+ let _ = (request, context);
+ std::future::ready(Ok(CreateElicitationResult {
+ action: ElicitationAction::Decline,
+ content: None,
+ }))
+ }
+
  fn on_cancelled(
  &self,
  params: CancelledNotificationParam,

crates/rmcp/src/model.rs

@@ -143,6 +143,7 @@ impl std::fmt::Display for ProtocolVersion {
 }
 
 impl ProtocolVersion {
+ pub const V_2025_06_18: Self = Self(Cow::Borrowed("2025-06-18"));
  pub const V_2025_03_26: Self = Self(Cow::Borrowed("2025-03-26"));
  pub const V_2024_11_05: Self = Self(Cow::Borrowed("2024-11-05"));
  pub const LATEST: Self = Self::V_2025_03_26;
@@ -167,6 +168,7 @@ impl<'de> Deserialize<'de> for ProtocolVersion {
  match s.as_str() {
  "2024-11-05" => return Ok(ProtocolVersion::V_2024_11_05),
  "2025-03-26" => return Ok(ProtocolVersion::V_2025_03_26),
+ "2025-06-18" => return Ok(ProtocolVersion::V_2025_06_18),
  _ => {}
  }
  Ok(ProtocolVersion(Cow::Owned(s)))
@@ -1173,6 +1175,75 @@ pub struct ListRootsResult {
 const_string!(RootsListChangedNotificationMethod = "notifications/roots/list_changed");
 pub type RootsListChangedNotification = NotificationNoParam<RootsListChangedNotificationMethod>;
 
+// =============================================================================
+// ELICITATION (INTERACTIVE USER INPUT)
+// =============================================================================
+
+// Method constants for elicitation operations.
+// Elicitation allows servers to request interactive input from users during tool execution.
+const_string!(ElicitationCreateRequestMethod = "elicitation/create");
+const_string!(ElicitationResponseNotificationMethod = "notifications/elicitation/response");
+
+/// Represents the possible actions a user can take in response to an elicitation request.
+///
+/// When a server requests user input through elicitation, the user can:
+/// - Accept: Provide the requested information and continue
+/// - Decline: Refuse to provide the information but continue the operation
+/// - Cancel: Stop the entire operation
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[serde(rename_all = "lowercase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub enum ElicitationAction {
+ /// User accepts the request and provides the requested information
+ Accept,
+ /// User declines to provide the information but allows the operation to continue
+ Decline,
+ /// User cancels the entire operation
+ Cancel,
+}
+
+/// Parameters for creating an elicitation request to gather user input.
+///
+/// This structure contains everything needed to request interactive input from a user:
+/// - A human-readable message explaining what information is needed
+/// - A JSON schema defining the expected structure of the response
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct CreateElicitationRequestParam {
+ /// Human-readable message explaining what input is needed from the user.
+ /// This should be clear and provide sufficient context for the user to understand
+ /// what information they need to provide.
+ pub message: String,
+
+ /// JSON Schema defining the expected structure and validation rules for the user's response.
+ /// This allows clients to validate input and provide appropriate UI controls.
+ /// Must be a valid JSON Schema Draft 2020-12 object.
+ pub requested_schema: JsonObject,
+}
+
+/// The result returned by a client in response to an elicitation request.
+///
+/// Contains the user's decision (accept/decline/cancel) and optionally their input data
+/// if they chose to accept the request.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct CreateElicitationResult {
+ /// The user's decision on how to handle the elicitation request
+ pub action: ElicitationAction,
+
+ /// The actual data provided by the user, if they accepted the request.
+ /// Must conform to the JSON schema specified in the original request.
+ /// Only present when action is Accept.
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub content: Option<Value>,
+}
+
+/// Request type for creating an elicitation to gather user input
+pub type CreateElicitationRequest =
+ Request<ElicitationCreateRequestMethod, CreateElicitationRequestParam>;
+
 // =============================================================================
 // TOOL EXECUTION RESULTS
 // =============================================================================
@@ -1430,7 +1501,7 @@ ts_union!(
 );
 
 ts_union!(
- export type ClientResult = CreateMessageResult | ListRootsResult | EmptyResult;
+ export type ClientResult = CreateMessageResult | ListRootsResult | CreateElicitationResult | EmptyResult;
 );
 
 impl ClientResult {
@@ -1445,7 +1516,8 @@ ts_union!(
  export type ServerRequest =
  | PingRequest
  | CreateMessageRequest
- | ListRootsRequest;
+ | ListRootsRequest
+ | CreateElicitationRequest;
 );
 
 ts_union!(
@@ -1470,6 +1542,7 @@ ts_union!(
  | ReadResourceResult
  | CallToolResult
  | ListToolsResult
+ | CreateElicitationResult
  | EmptyResult
  ;
 );

crates/rmcp/src/model/capabilities.rs

@@ -40,6 +40,22 @@ pub struct RootsCapabilities {
  pub list_changed: Option<bool>,
 }
 
+/// Capability for handling elicitation requests from servers.
+///
+/// Elicitation allows servers to request interactive input from users during tool execution.
+/// This capability indicates that a client can handle elicitation requests and present
+/// appropriate UI to users for collecting the requested information.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Default)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct ElicitationCapability {
+ /// Whether the client supports JSON Schema validation for elicitation responses.
+ /// When true, the client will validate user input against the requested_schema
+ /// before sending the response back to the server.
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub schema_validation: Option<bool>,
+}
+
 ///
 /// # Builder
 /// ```rust
@@ -59,6 +75,9 @@ pub struct ClientCapabilities {
  pub roots: Option<RootsCapabilities>,
  #[serde(skip_serializing_if = "Option::is_none")]
  pub sampling: Option<JsonObject>,
+ /// Capability to handle elicitation requests from servers for interactive user input
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub elicitation: Option<ElicitationCapability>,
 }
 
 ///
@@ -253,6 +272,7 @@ builder! {
  experimental: ExperimentalCapabilities,
  roots: RootsCapabilities,
  sampling: JsonObject,
+ elicitation: ElicitationCapability,
  }
 }
 
@@ -267,6 +287,21 @@ impl<const E: bool, const S: bool>
  }
 }
 
+#[cfg(feature = "elicitation")]
+impl<const E: bool, const R: bool, const S: bool>
+ ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<E, R, S, true>>
+{
+ /// Enable JSON Schema validation for elicitation responses.
+ /// When enabled, the client will validate user input against the requested_schema
+ /// before sending responses back to the server.
+ pub fn enable_elicitation_schema_validation(mut self) -> Self {
+ if let Some(c) = self.elicitation.as_mut() {
+ c.schema_validation = Some(true);
+ }
+ self
+ }
+}
+
 #[cfg(test)]
 mod test {
  use super::*;

crates/rmcp/src/model/meta.rs

@@ -74,6 +74,7 @@ variant_extension! {
  PingRequest
  CreateMessageRequest
  ListRootsRequest
+ CreateElicitationRequest
  }
 }
 

crates/rmcp/Cargo.toml

@@ -79,6 +79,7 @@ default = ["base64", "macros", "server"]
 client = ["dep:tokio-stream"]
 server = ["transport-async-rw", "dep:schemars"]
 macros = ["dep:rmcp-macros", "dep:paste"]
+elicitation = []
 
 # reqwest http client
 __reqwest = ["dep:reqwest"]
@@ -201,3 +202,8 @@ path = "tests/test_message_schema.rs"
 name = "test_progress_subscriber"
 required-features = ["server", "client", "macros"]
 path = "tests/test_progress_subscriber.rs"
+
+[[test]]
+name = "test_elicitation"
+required-features = ["elicitation", "client", "server"]
+path = "tests/test_elicitation.rs"

crates/rmcp/src/handler/client.rs

@@ -21,6 +21,10 @@ impl<H: ClientHandler> Service<RoleClient> for H {
  .list_roots(context)
  .await
  .map(ClientResult::ListRootsResult),
+ ServerRequest::CreateElicitationRequest(request) => self
+ .create_elicitation(request.params, context)
+ .await
+ .map(ClientResult::CreateElicitationResult),
  }
  }
 
@@ -86,6 +90,35 @@ pub trait ClientHandler: Sized + Send + Sync + 'static {
  std::future::ready(Ok(ListRootsResult::default()))
  }
 
+ /// Handle an elicitation request from a server asking for user input.
+ ///
+ /// This method is called when a server needs interactive input from the user
+ /// during tool execution. Implementations should present the message to the user,
+ /// collect their input according to the requested schema, and return the result.
+ ///
+ /// # Arguments
+ /// * `request` - The elicitation request with message and schema
+ /// * `context` - The request context
+ ///
+ /// # Returns
+ /// The user's response including action (accept/decline/cancel) and optional data
+ ///
+ /// # Default Behavior
+ /// The default implementation automatically declines all elicitation requests.
+ /// Real clients should override this to provide user interaction.
+ fn create_elicitation(
+ &self,
+ request: CreateElicitationRequestParam,
+ context: RequestContext<RoleClient>,
+ ) -> impl Future<Output = Result<CreateElicitationResult, McpError>> + Send + '_ {
+ // Default implementation declines all requests - real clients should override this
+ let _ = (request, context);
+ std::future::ready(Ok(CreateElicitationResult {
+ action: ElicitationAction::Decline,
+ content: None,
+ }))
+ }
+
  fn on_cancelled(
  &self,
  params: CancelledNotificationParam,

crates/rmcp/src/model.rs

@@ -143,6 +143,7 @@ impl std::fmt::Display for ProtocolVersion {
 }
 
 impl ProtocolVersion {
+ pub const V_2025_06_18: Self = Self(Cow::Borrowed("2025-06-18"));
  pub const V_2025_03_26: Self = Self(Cow::Borrowed("2025-03-26"));
  pub const V_2024_11_05: Self = Self(Cow::Borrowed("2024-11-05"));
  pub const LATEST: Self = Self::V_2025_03_26;
@@ -167,6 +168,7 @@ impl<'de> Deserialize<'de> for ProtocolVersion {
  match s.as_str() {
  "2024-11-05" => return Ok(ProtocolVersion::V_2024_11_05),
  "2025-03-26" => return Ok(ProtocolVersion::V_2025_03_26),
+ "2025-06-18" => return Ok(ProtocolVersion::V_2025_06_18),
  _ => {}
  }
  Ok(ProtocolVersion(Cow::Owned(s)))
@@ -1173,6 +1175,75 @@ pub struct ListRootsResult {
 const_string!(RootsListChangedNotificationMethod = "notifications/roots/list_changed");
 pub type RootsListChangedNotification = NotificationNoParam<RootsListChangedNotificationMethod>;
 
+// =============================================================================
+// ELICITATION (INTERACTIVE USER INPUT)
+// =============================================================================
+
+// Method constants for elicitation operations.
+// Elicitation allows servers to request interactive input from users during tool execution.
+const_string!(ElicitationCreateRequestMethod = "elicitation/create");
+const_string!(ElicitationResponseNotificationMethod = "notifications/elicitation/response");
+
+/// Represents the possible actions a user can take in response to an elicitation request.
+///
+/// When a server requests user input through elicitation, the user can:
+/// - Accept: Provide the requested information and continue
+/// - Decline: Refuse to provide the information but continue the operation
+/// - Cancel: Stop the entire operation
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[serde(rename_all = "lowercase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub enum ElicitationAction {
+ /// User accepts the request and provides the requested information
+ Accept,
+ /// User declines to provide the information but allows the operation to continue
+ Decline,
+ /// User cancels the entire operation
+ Cancel,
+}
+
+/// Parameters for creating an elicitation request to gather user input.
+///
+/// This structure contains everything needed to request interactive input from a user:
+/// - A human-readable message explaining what information is needed
+/// - A JSON schema defining the expected structure of the response
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct CreateElicitationRequestParam {
+ /// Human-readable message explaining what input is needed from the user.
+ /// This should be clear and provide sufficient context for the user to understand
+ /// what information they need to provide.
+ pub message: String,
+
+ /// JSON Schema defining the expected structure and validation rules for the user's response.
+ /// This allows clients to validate input and provide appropriate UI controls.
+ /// Must be a valid JSON Schema Draft 2020-12 object.
+ pub requested_schema: JsonObject,
+}
+
+/// The result returned by a client in response to an elicitation request.
+///
+/// Contains the user's decision (accept/decline/cancel) and optionally their input data
+/// if they chose to accept the request.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct CreateElicitationResult {
+ /// The user's decision on how to handle the elicitation request
+ pub action: ElicitationAction,
+
+ /// The actual data provided by the user, if they accepted the request.
+ /// Must conform to the JSON schema specified in the original request.
+ /// Only present when action is Accept.
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub content: Option<Value>,
+}
+
+/// Request type for creating an elicitation to gather user input
+pub type CreateElicitationRequest =
+ Request<ElicitationCreateRequestMethod, CreateElicitationRequestParam>;
+
 // =============================================================================
 // TOOL EXECUTION RESULTS
 // =============================================================================
@@ -1430,7 +1501,7 @@ ts_union!(
 );
 
 ts_union!(
- export type ClientResult = CreateMessageResult | ListRootsResult | EmptyResult;
+ export type ClientResult = CreateMessageResult | ListRootsResult | CreateElicitationResult | EmptyResult;
 );
 
 impl ClientResult {
@@ -1445,7 +1516,8 @@ ts_union!(
  export type ServerRequest =
  | PingRequest
  | CreateMessageRequest
- | ListRootsRequest;
+ | ListRootsRequest
+ | CreateElicitationRequest;
 );
 
 ts_union!(
@@ -1470,6 +1542,7 @@ ts_union!(
  | ReadResourceResult
  | CallToolResult
  | ListToolsResult
+ | CreateElicitationResult
  | EmptyResult
  ;
 );

crates/rmcp/src/model/capabilities.rs

@@ -40,6 +40,22 @@ pub struct RootsCapabilities {
  pub list_changed: Option<bool>,
 }
 
+/// Capability for handling elicitation requests from servers.
+///
+/// Elicitation allows servers to request interactive input from users during tool execution.
+/// This capability indicates that a client can handle elicitation requests and present
+/// appropriate UI to users for collecting the requested information.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Default)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct ElicitationCapability {
+ /// Whether the client supports JSON Schema validation for elicitation responses.
+ /// When true, the client will validate user input against the requested_schema
+ /// before sending the response back to the server.
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub schema_validation: Option<bool>,
+}
+
 ///
 /// # Builder
 /// ```rust
@@ -59,6 +75,9 @@ pub struct ClientCapabilities {
  pub roots: Option<RootsCapabilities>,
  #[serde(skip_serializing_if = "Option::is_none")]
  pub sampling: Option<JsonObject>,
+ /// Capability to handle elicitation requests from servers for interactive user input
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub elicitation: Option<ElicitationCapability>,
 }
 
 ///
@@ -253,6 +272,7 @@ builder! {
  experimental: ExperimentalCapabilities,
  roots: RootsCapabilities,
  sampling: JsonObject,
+ elicitation: ElicitationCapability,
  }
 }
 
@@ -267,6 +287,21 @@ impl<const E: bool, const S: bool>
  }
 }
 
+#[cfg(feature = "elicitation")]
+impl<const E: bool, const R: bool, const S: bool>
+ ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<E, R, S, true>>
+{
+ /// Enable JSON Schema validation for elicitation responses.
+ /// When enabled, the client will validate user input against the requested_schema
+ /// before sending responses back to the server.
+ pub fn enable_elicitation_schema_validation(mut self) -> Self {
+ if let Some(c) = self.elicitation.as_mut() {
+ c.schema_validation = Some(true);
+ }
+ self
+ }
+}
+
 #[cfg(test)]
 mod test {
  use super::*;

crates/rmcp/src/model/meta.rs

@@ -74,6 +74,7 @@ variant_extension! {
  PingRequest
  CreateMessageRequest
  ListRootsRequest
+ CreateElicitationRequest
  }
 }
 

crates/rmcp/Cargo.toml

@@ -79,6 +79,7 @@ default = ["base64", "macros", "server"]
 client = ["dep:tokio-stream"]
 server = ["transport-async-rw", "dep:schemars"]
 macros = ["dep:rmcp-macros", "dep:paste"]
+elicitation = []
 
 # reqwest http client
 __reqwest = ["dep:reqwest"]
@@ -201,3 +202,8 @@ path = "tests/test_message_schema.rs"
 name = "test_progress_subscriber"
 required-features = ["server", "client", "macros"]
 path = "tests/test_progress_subscriber.rs"
+
+[[test]]
+name = "test_elicitation"
+required-features = ["elicitation", "client", "server"]
+path = "tests/test_elicitation.rs"

crates/rmcp/src/handler/client.rs

@@ -21,6 +21,10 @@ impl<H: ClientHandler> Service<RoleClient> for H {
  .list_roots(context)
  .await
  .map(ClientResult::ListRootsResult),
+ ServerRequest::CreateElicitationRequest(request) => self
+ .create_elicitation(request.params, context)
+ .await
+ .map(ClientResult::CreateElicitationResult),
  }
  }
 
@@ -86,6 +90,35 @@ pub trait ClientHandler: Sized + Send + Sync + 'static {
  std::future::ready(Ok(ListRootsResult::default()))
  }
 
+ /// Handle an elicitation request from a server asking for user input.
+ ///
+ /// This method is called when a server needs interactive input from the user
+ /// during tool execution. Implementations should present the message to the user,
+ /// collect their input according to the requested schema, and return the result.
+ ///
+ /// # Arguments
+ /// * `request` - The elicitation request with message and schema
+ /// * `context` - The request context
+ ///
+ /// # Returns
+ /// The user's response including action (accept/decline/cancel) and optional data
+ ///
+ /// # Default Behavior
+ /// The default implementation automatically declines all elicitation requests.
+ /// Real clients should override this to provide user interaction.
+ fn create_elicitation(
+ &self,
+ request: CreateElicitationRequestParam,
+ context: RequestContext<RoleClient>,
+ ) -> impl Future<Output = Result<CreateElicitationResult, McpError>> + Send + '_ {
+ // Default implementation declines all requests - real clients should override this
+ let _ = (request, context);
+ std::future::ready(Ok(CreateElicitationResult {
+ action: ElicitationAction::Decline,
+ content: None,
+ }))
+ }
+
  fn on_cancelled(
  &self,
  params: CancelledNotificationParam,

crates/rmcp/src/model.rs

@@ -143,6 +143,7 @@ impl std::fmt::Display for ProtocolVersion {
 }
 
 impl ProtocolVersion {
+ pub const V_2025_06_18: Self = Self(Cow::Borrowed("2025-06-18"));
  pub const V_2025_03_26: Self = Self(Cow::Borrowed("2025-03-26"));
  pub const V_2024_11_05: Self = Self(Cow::Borrowed("2024-11-05"));
  pub const LATEST: Self = Self::V_2025_03_26;
@@ -167,6 +168,7 @@ impl<'de> Deserialize<'de> for ProtocolVersion {
  match s.as_str() {
  "2024-11-05" => return Ok(ProtocolVersion::V_2024_11_05),
  "2025-03-26" => return Ok(ProtocolVersion::V_2025_03_26),
+ "2025-06-18" => return Ok(ProtocolVersion::V_2025_06_18),
  _ => {}
  }
  Ok(ProtocolVersion(Cow::Owned(s)))
@@ -1173,6 +1175,75 @@ pub struct ListRootsResult {
 const_string!(RootsListChangedNotificationMethod = "notifications/roots/list_changed");
 pub type RootsListChangedNotification = NotificationNoParam<RootsListChangedNotificationMethod>;
 
+// =============================================================================
+// ELICITATION (INTERACTIVE USER INPUT)
+// =============================================================================
+
+// Method constants for elicitation operations.
+// Elicitation allows servers to request interactive input from users during tool execution.
+const_string!(ElicitationCreateRequestMethod = "elicitation/create");
+const_string!(ElicitationResponseNotificationMethod = "notifications/elicitation/response");
+
+/// Represents the possible actions a user can take in response to an elicitation request.
+///
+/// When a server requests user input through elicitation, the user can:
+/// - Accept: Provide the requested information and continue
+/// - Decline: Refuse to provide the information but continue the operation
+/// - Cancel: Stop the entire operation
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
+#[serde(rename_all = "lowercase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub enum ElicitationAction {
+ /// User accepts the request and provides the requested information
+ Accept,
+ /// User declines to provide the information but allows the operation to continue
+ Decline,
+ /// User cancels the entire operation
+ Cancel,
+}
+
+/// Parameters for creating an elicitation request to gather user input.
+///
+/// This structure contains everything needed to request interactive input from a user:
+/// - A human-readable message explaining what information is needed
+/// - A JSON schema defining the expected structure of the response
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct CreateElicitationRequestParam {
+ /// Human-readable message explaining what input is needed from the user.
+ /// This should be clear and provide sufficient context for the user to understand
+ /// what information they need to provide.
+ pub message: String,
+
+ /// JSON Schema defining the expected structure and validation rules for the user's response.
+ /// This allows clients to validate input and provide appropriate UI controls.
+ /// Must be a valid JSON Schema Draft 2020-12 object.
+ pub requested_schema: JsonObject,
+}
+
+/// The result returned by a client in response to an elicitation request.
+///
+/// Contains the user's decision (accept/decline/cancel) and optionally their input data
+/// if they chose to accept the request.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct CreateElicitationResult {
+ /// The user's decision on how to handle the elicitation request
+ pub action: ElicitationAction,
+
+ /// The actual data provided by the user, if they accepted the request.
+ /// Must conform to the JSON schema specified in the original request.
+ /// Only present when action is Accept.
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub content: Option<Value>,
+}
+
+/// Request type for creating an elicitation to gather user input
+pub type CreateElicitationRequest =
+ Request<ElicitationCreateRequestMethod, CreateElicitationRequestParam>;
+
 // =============================================================================
 // TOOL EXECUTION RESULTS
 // =============================================================================
@@ -1430,7 +1501,7 @@ ts_union!(
 );
 
 ts_union!(
- export type ClientResult = CreateMessageResult | ListRootsResult | EmptyResult;
+ export type ClientResult = CreateMessageResult | ListRootsResult | CreateElicitationResult | EmptyResult;
 );
 
 impl ClientResult {
@@ -1445,7 +1516,8 @@ ts_union!(
  export type ServerRequest =
  | PingRequest
  | CreateMessageRequest
- | ListRootsRequest;
+ | ListRootsRequest
+ | CreateElicitationRequest;
 );
 
 ts_union!(
@@ -1470,6 +1542,7 @@ ts_union!(
  | ReadResourceResult
  | CallToolResult
  | ListToolsResult
+ | CreateElicitationResult
  | EmptyResult
  ;
 );

crates/rmcp/src/model/capabilities.rs

@@ -40,6 +40,22 @@ pub struct RootsCapabilities {
  pub list_changed: Option<bool>,
 }
 
+/// Capability for handling elicitation requests from servers.
+///
+/// Elicitation allows servers to request interactive input from users during tool execution.
+/// This capability indicates that a client can handle elicitation requests and present
+/// appropriate UI to users for collecting the requested information.
+#[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Default)]
+#[serde(rename_all = "camelCase")]
+#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+pub struct ElicitationCapability {
+ /// Whether the client supports JSON Schema validation for elicitation responses.
+ /// When true, the client will validate user input against the requested_schema
+ /// before sending the response back to the server.
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub schema_validation: Option<bool>,
+}
+
 ///
 /// # Builder
 /// ```rust
@@ -59,6 +75,9 @@ pub struct ClientCapabilities {
  pub roots: Option<RootsCapabilities>,
  #[serde(skip_serializing_if = "Option::is_none")]
  pub sampling: Option<JsonObject>,
+ /// Capability to handle elicitation requests from servers for interactive user input
+ #[serde(skip_serializing_if = "Option::is_none")]
+ pub elicitation: Option<ElicitationCapability>,
 }
 
 ///
@@ -253,6 +272,7 @@ builder! {
  experimental: ExperimentalCapabilities,
  roots: RootsCapabilities,
  sampling: JsonObject,
+ elicitation: ElicitationCapability,
  }
 }
 
@@ -267,6 +287,21 @@ impl<const E: bool, const S: bool>
  }
 }
 
+#[cfg(feature = "elicitation")]
+impl<const E: bool, const R: bool, const S: bool>
+ ClientCapabilitiesBuilder<ClientCapabilitiesBuilderState<E, R, S, true>>
+{
+ /// Enable JSON Schema validation for elicitation responses.
+ /// When enabled, the client will validate user input against the requested_schema
+ /// before sending responses back to the server.
+ pub fn enable_elicitation_schema_validation(mut self) -> Self {
+ if let Some(c) = self.elicitation.as_mut() {
+ c.schema_validation = Some(true);
+ }
+ self
+ }
+}
+
 #[cfg(test)]
 mod test {
  use super::*;

crates/rmcp/src/model/meta.rs

@@ -74,6 +74,7 @@ variant_extension! {
  PingRequest
  CreateMessageRequest
  ListRootsRequest
+ CreateElicitationRequest
  }
 }