mfl-mcp-client

name	mfl-mcp-client
description	Using machin-mcp as a tool server from any MCP-compatible client (Claude Code, Claude Desktop) or directly via bash from pi or other agents. Covers registration, tool discovery, and direct protocol calls.

Using machin-mcp as a Tool Server

machin-mcp is a 31 KB static binary MCP server. It exposes 6 tools over stdio using JSON-RPC 2.0.

Option 1: Claude Code (native MCP support)

# Register the server
claude mcp add machin-mcp -- /path/to/machin-mcp

# Verify it's connected
claude mcp get machin-mcp

# Now Claude Code can use all 6 tools in conversations
# It discovers them automatically via tools/list

Once registered, Claude Code will automatically:

1. Call tools/list on startup to discover available tools
2. Display them in the 🔌 MCP servers panel
3. Call tools/call when it decides a tool would help
4. Pass the results back to the LLM

Option 2: Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "machin-mcp": {
      "command": "/path/to/machin-mcp"
    }
  }
}

Option 3: Direct from any agent (pi, Claude Code CLI, etc.)

Call the MCP server directly via bash. Each request is one JSON line → one JSON line response.

Initialize session

echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{}}' | ./mcp
# → {"jsonrpc":"2.0","id":1,"result":{"protocolVersion":"2024-11-05","capabilities":{"tools":{}},"serverInfo":{"name":"machin-mcp","version":"1.0.0"}}}

Discover tools

echo '{"jsonrpc":"2.0","id":1,"method":"tools/list"}' | ./mcp
# → lists all 6 tools with their JSON schemas

Call a tool

echo '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"now","arguments":{}}}' | ./mcp
# → {"jsonrpc":"2.0","id":1,"result":{"content":[{"type":"text","text":"2026-06-25 12:34:56"}]}}

echo '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"read_file","arguments":{"path":"/etc/hostname"}}}' | ./mcp

Multi-request session (persistent)

For multiple requests, pipe them all to one server process:

{
  echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{}}'
  echo '{"jsonrpc":"2.0","method":"notifications/initialized"}'
  echo '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"now","arguments":{}}}'
  echo '{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"list_dir","arguments":{"path":"."}}}'
} | ./mcp

Available tools

Tool	What it does	When an agent should use it
echo	Echoes back input	Testing MCP connectivity
now	Returns current date/time	When the agent needs to know the current time
read_file	Reads any file	Inspecting logs, configs, source files
write_file	Writes content to a file	Creating/modifying files with structured content
list_dir	Lists directory entries	Exploring directory structure
sqlite_query	Runs SQL queries	Querying SQLite databases, inspecting data

Protocol notes for agents

• JSON must be compact (single line) — the stdio transport reads one line per message
• Initialize first — initialize must be the first call; notifications/initialized is optional
• Notifications (no id field) get no response — send them but don't wait for a reply
• String arguments — use json() in MFL or json.dumps() in Python to properly escape strings with newlines, quotes, etc.
• Error responses have "isError":true in the result — check for this before using the content
• Unknown methods return error code -32601 (MethodNotFound)

Example: pi using machin-mcp via bash

In a pi session, the agent can call machin-mcp tools using the bash tool:

# Agent needs the current time
echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{}}' | /path/to/machin-mcp | tail -1 | python3 -c "import json,sys; print(json.load(sys.stdin)['result']['serverInfo'])"

# Agent needs to read a file
printf '%s\n' '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{}}' '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"read_file","arguments":{"path":"/var/log/syslog"}}}' | /path/to/machin-mcp | tail -1