#mcpc

A standalone Model Context Protocol (MCP) client CLI written in Rust.

mcpc talks to MCP servers over Streamable HTTP or stdio JSON-RPC and keeps a small local daemon so that multiple CLI invocations share the same connection/session.

#Install

cargo install --path .
# or via Homebrew
brew install lloydzhou/tap/mcpc

# or via APT (Debian/Ubuntu; the repository is hosted alongside bash-agent)
curl -fsSL https://lloydzhou.github.io/bash-agent/install.sh | sudo bash
sudo apt-get install mcpc

# or via AUR (Arch Linux; mcpc-bin for the prebuilt binary)
yay -S mcpc

#Usage

# Streamable HTTP server
mcpc connect https://example.com/mcp @myserver

# stdio JSON-RPC server
mcpc connect cmd:"node server.js" @myserver

# list cached/live sessions
mcpc ls

# call a tool
mcpc @myserver tools-call echo msg=hello

# ping a session
mcpc @myserver ping

# close a session
mcpc close @myserver

# stop the daemon
mcpc daemon stop

#CLI overview

mcpc connect URL [@NAME]
mcpc connect cmd:COMMAND [@NAME]
mcpc ls | close @NAME | daemon stop | grep PATTERN
mcpc @NAME tools-list [--full] | tools-get TOOL | tools-call TOOL [K=V|K:=JSON...] | ping

Global flags: --json, --insecure, --timeout N, -H HEADER, --protocol-version VER.

#Daemon design

• Every mcpc command is a short-lived process that talks to a local Unix socket.
• If the daemon is not running it is started implicitly in the background.
• The daemon holds the actual transport connection and mirrors session metadata to $MCPC_HOME/servers/*.json so tools can be listed/grepped offline.
• daemon stop kills stdio child processes and cleans up the socket/pid files.

#Data directory

$MCPC_HOME → $BA_HOME/mcpc → ~/.local/share/mcpc.

#Development

cargo build
cargo test
bash tests/test.sh          # e2e tests (stdio + HTTP + SSE)

#Relationship to bash-agent

This tool implements the MCP client half of the functionality discussed in bash-agent#88. It is a standalone Rust port of the mcpc applet from lloydzhou/busyagent PR #4, sharing the same CLI/JSON contract so it can be composed with bash-agent or used on its own.

#License

MIT