elicitation_derive

Derive macros for the elicitation crate.

Usage

use elicitation::Elicit;
use schemars::JsonSchema;

#[derive(Debug, Clone, Elicit, JsonSchema)]
struct Config {
    host: String,
    port: u16,
}

Important: You must include #[derive(schemars::JsonSchema)] along with #[derive(Elicit)]. This is required because the generated elicit_checked() function returns Self, which must implement JsonSchema for rmcp's #[tool] attribute to work properly.

What Gets Generated

The #[derive(Elicit)] macro generates:

1. Elicitation trait implementation - Async elicitation logic
2. elicit_checked() function - MCP tool decorated with #[rmcp::tool]
3. Supporting traits - Prompt, Select (for enums), Survey (for structs)

Why JsonSchema is Required

The generated tool function looks like:

#[rmcp::tool]
pub async fn elicit_checked(peer: Peer<RoleServer>) -> Result<Self, ElicitError> {
    // ...
}

The #[rmcp::tool] macro requires the return type (Self) to implement JsonSchema for OpenAPI/JSON Schema generation.

Example with Tool Router

use elicitation::{Elicit, elicit_router};
use schemars::JsonSchema;

#[derive(Debug, Clone, Elicit, JsonSchema)]
struct ServerConfig {
    host: String,
    port: u16,
}

#[derive(Debug, Clone, Elicit, JsonSchema)]
struct UserProfile {
    username: String,
    email: String,
}

// Generate router with all tools
elicit_router! {
    pub MyTools: ServerConfig, UserProfile
}

This generates MCP tools:

• elicit_checked_ServerConfig(peer)
• elicit_checked_UserProfile(peer)

All automatically registered and ready to use!