rmcp-server-builder

Composable MCP server builder for zero-boilerplate capability composition.

Overview

This crate provides a builder pattern for composing MCP servers from individual capability providers, eliminating the boilerplate of implementing ServerHandler and manually delegating methods.

Instead of implementing the full ServerHandler trait:

// Traditional approach - lots of boilerplate
impl ServerHandler for MyServer {
    fn list_tools(&self, ...) -> ... { self.tools.list_tools(...) }
    fn call_tool(&self, ...) -> ... { self.tools.call_tool(...) }
    fn list_prompts(&self, ...) -> ... { self.prompts.list_prompts(...) }
    fn get_prompt(&self, ...) -> ... { self.prompts.get_prompt(...) }
    // ... many more delegations
}

You can compose a server from individual providers:

use rmcp_server_builder::ServerBuilder;
use rmcp::model::Implementation;

let server = ServerBuilder::new()
    .info(Implementation::from_build_env())
    .instructions("A helpful assistant with access to various tools.")
    .tools(my_tools_provider)
    .prompts(my_prompts_provider)
    .build();

Installation

Add to your Cargo.toml:

[dependencies]
rmcp-server-builder = "0.1"
rmcp = { version = "0.12", features = ["server"] }

Development

cargo build
cargo test
cargo clippy --all-targets --all-features -- -D warnings
cargo fmt --all -- --check

License

MIT