bote

MCP core service for Rust.

JSON-RPC 2.0 protocol, tool registry, schema validation, and dispatch — in a single crate. Eliminates 23 separate MCP server implementations across the AGNOS ecosystem.

Name: Bote (German) — messenger. The messenger between agents and tools.

What it does

bote is the MCP protocol layer — it handles the JSON-RPC 2.0 wire format, tool registration, schema validation, and call dispatch so individual apps don't each reimplement the same protocol.

Feature Flags

None are enabled by default — enable only what you need.

Quick start

[dependencies]
bote = "0.22"

use std::sync::Arc;
use std::collections::HashMap;
use bote::{Dispatcher, ToolRegistry, ToolDef, ToolSchema, JsonRpcRequest};

// Register tools
let mut registry = ToolRegistry::new();
registry.register(ToolDef {
    name: "my_tool".into(),
    description: "Does something useful".into(),
    input_schema: ToolSchema {
        schema_type: "object".into(),
        properties: HashMap::new(),
        required: vec!["input".into()],
    },
});

// Wire up handlers
let mut dispatcher = Dispatcher::new(registry);
dispatcher.handle("my_tool", Arc::new(|params| {
    let input = params["input"].as_str().unwrap_or("none");
    serde_json::json!({
        "content": [{ "type": "text", "text": format!("result: {input}") }]
    })
}));

// Dispatch requests
let request = JsonRpcRequest::new(1, "tools/call")
    .with_params(serde_json::json!({
        "name": "my_tool",
        "arguments": { "input": "hello" }
    }));

let response = dispatcher.dispatch(&request).unwrap();
// response.result = {"content": [{"type": "text", "text": "result: hello"}]}

MCP server (stdio)

use bote::transport::stdio;

// Runs a blocking loop: reads JSON-RPC from stdin, dispatches, writes to stdout.
stdio::run(&dispatcher)?;

HTTP transport

[dependencies]
bote = { version = "0.22", features = ["http"] }

use bote::transport::http::{serve, HttpConfig};
use std::sync::Arc;

let config = HttpConfig { addr: "127.0.0.1:3000".parse().unwrap() };
serve(Arc::new(dispatcher), config, shutdown_signal).await?;
// POST / for JSON-RPC, GET /health for liveness

MCP Protocol

bote implements the Model Context Protocol over JSON-RPC 2.0:

Error codes

Why bote?

Every AGNOS consumer app currently implements its own MCP server:

Before bote:                          After bote:
─────────────                         ────────────
jalwa/src/mcp.rs    (150 lines)       jalwa: bote::Dispatcher + 5 handlers
shruti/src/mcp.rs   (180 lines)       shruti: bote::Dispatcher + 7 handlers
tazama/src/mcp.rs   (160 lines)       tazama: bote::Dispatcher + 7 handlers
rasa/src/mcp.rs     (200 lines)       rasa: bote::Dispatcher + 9 handlers
... × 23 apps       (~4000 lines)     ... × 23 apps (0 protocol code)

4000 lines of duplicated JSON-RPC parsing replaced by bote = "0.22" in Cargo.toml.

Who uses this

Roadmap

Full details: docs/development/roadmap.md

Building from source

git clone https://github.com/MacCracken/bote.git
cd bote
make check          # fmt + clippy + test + audit
make test-all       # test every feature flag
make bench          # run benchmarks + log history
make coverage       # HTML coverage report

Versioning

Pre-1.0: 0.D.M SemVer (day.month). Post-1.0: standard SemVer.

License

AGPL-3.0-only. See LICENSE for details.