stdio

mcp/stdio — local MCP stdio transport

Runs the supported MCP surface as newline-delimited JSON-RPC over stdin and stdout. stdout carries protocol responses only; diagnostics use stderr.

Lifecycle and flow control

This is a local child-process adapter. It accepts one complete line, handles it synchronously, writes at most one response, then reads the next line. There is no request queue, concurrent execution, or partial-result mode: a slow tool call applies backpressure through stdin. EOF is the supported shutdown signal. notifications/initialized and notifications/cancelled are accepted notifications and deliberately write no response. Cancellation cannot interrupt an already-running synchronous call; hosts should stop the child process if they need hard cancellation.

Values

main

pub fn main() -> Nil

Start a local MCP server with a fresh in-memory AaronDB instance.

parse_request

pub fn parse_request(
  line: String,
) -> Result(server.JsonRpcRequest, json.DecodeError)

serve

pub fn serve(db: process.Subject(transactor.Message)) -> Nil

Serve one JSON-RPC request per stdin line until EOF.

serve_line

pub fn serve_line(
  db: process.Subject(transactor.Message),
  line: String,
) -> option.Option(server.JsonRpcResponse)

Decode and synchronously handle one stdin line.

A request produces Some(response). JSON-RPC notifications intentionally produce None, including malformed notifications only when they cannot be identified as notifications.