mcp_elicit

The mcp_elicit macro generates type-safe elicitation request and response handling.

#[macros::mcp_elicit(message = "Please enter your info", mode = form)]
#[derive(JsonSchema)]
pub struct UserInfo {
    #[json_schema(title = "Name", min_length = 5, max_length = 100)]
    pub name: String,
    #[json_schema(title = "Email", format = "email")]
    pub email: Option<String>,
    #[json_schema(title = "Age", minimum = 15, maximum = 125)]
    pub age: i32,
}

Generated methods:

• UserInfo::elicit_request_params() - creates ElicitRequestParams
• UserInfo::from_elicit_result_content(content) - parses the response

Modes

• form - Client shows a structured form (default)
• url - Client shows a URL for the user to visit; requires a companion url = "https://..." attribute

Usage

For form mode, elicit_request_params() takes no arguments:

let result: ElicitResult = server.request_elicitation(UserInfo::elicit_request_params()).await?;
let user = UserInfo::from_elicit_result_content(result.content)?;
println!("Hello, {}!", user.name);

For url mode, elicit_request_params() requires the elicitation ID from the server:

#[macros::mcp_elicit(message = "Please authorize access", mode = url, url = "https://example.com/authorize")]
#[derive(JsonSchema)]
pub struct AuthConfirmation { /* ... */ }

let params = AuthConfirmation::elicit_request_params(elicitation_id);
let result: ElicitResult = server.request_elicitation(params).await?;