rmcp 3.0.1

Rust SDK for Model Context Protocol
Documentation 
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#![cfg(all(feature = "client", not(feature = "local")))]

use rmcp::{
    ClientHandler, ServerHandler, ServiceExt,
    model::{
        ClientCapabilities, Implementation, ProtocolVersion, RequestMetaObject, ServerCapabilities,
        ServerInfo,
    },
    select_protocol_version,
};

#[derive(Clone, Default)]
struct DiscoveryServer;

impl ServerHandler for DiscoveryServer {
    fn get_info(&self) -> ServerInfo {
        ServerInfo::new(ServerCapabilities::builder().enable_tools().build())
            .with_server_info(Implementation::new("discovery-server", "1.0.0"))
    }
}

#[derive(Clone, Default)]
struct DiscoveryClient;

impl ClientHandler for DiscoveryClient {}

#[test]
fn select_protocol_version_uses_client_preference_order() {
    let selected = select_protocol_version(
        &[ProtocolVersion::V_2026_07_28, ProtocolVersion::V_2025_11_25],
        &[ProtocolVersion::V_2025_11_25, ProtocolVersion::V_2026_07_28],
    );

    assert_eq!(selected, Some(ProtocolVersion::V_2026_07_28));
}

#[test]
fn select_protocol_version_returns_none_without_overlap() {
    let selected = select_protocol_version(
        &[ProtocolVersion::V_2026_07_28],
        &[ProtocolVersion::V_2025_11_25],
    );

    assert_eq!(selected, None);
}

#[tokio::test]
async fn client_discover_helper_returns_typed_result() {
    let (server_transport, client_transport) = tokio::io::duplex(4096);
    tokio::spawn(async move {
        let _ = DiscoveryServer
            .serve(server_transport)
            .await
            .expect("server should start")
            .waiting()
            .await;
    });
    let client = DiscoveryClient
        .serve(client_transport)
        .await
        .expect("client should connect");
    let mut meta = RequestMetaObject::new();
    meta.set_protocol_version(ProtocolVersion::V_2026_07_28);
    meta.set_client_info(Implementation::new("discovery-client", "1.0.0"));
    meta.set_client_capabilities(ClientCapabilities::default());

    let result = client
        .discover(meta)
        .await
        .expect("discover should succeed");

    assert_eq!(
        result.server_info(),
        Some(Implementation::new("discovery-server", "1.0.0"))
    );
    client.cancel().await.expect("client should cancel");
}