sc-machin MCP Server Setup

sc-machin mcp serve exposes all installed SuperCLI commands (800+) plus built-in tools as MCP tools over JSON-RPC 2.0 (JSONL stdio transport). Any MCP client that spawns it gets the full SuperCLI tool graph.

Quick Install (Claude Code)

# 1. Build sc-machin (if not already built)
cd ~/ai/supercli/supercli-machin-cli && bash build.sh

# 2. Register at user scope (available in all projects)
claude mcp add supercli -s user -- "$(pwd)/sc-machin" mcp serve

# 3. Verify connection
claude mcp get supercli
# Should show: Status: ✔ Connected

Quick Install (Claude Desktop)

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "supercli": {
      "command": "/home/user/path/to/sc-machin",
      "args": ["mcp", "serve"]
    }
  }
}

Built-in MCP Tools

Beyond lockfile commands, sc-machin exposes two built-in tools:

skills.match

Searches all skill directories for SKILL.md files matching a task description. Returns top 5 matches with paths and descriptions.

Tool: mcp__supercli__skills_match
Arguments: { "task": "generate a changelog from git history" }

Directories scanned: ~/.agents/skills, ~/.claude/skills, ~/.config/devin/skills, ~/.codeium/windsurf/skills, .agents/skills, .claude/skills

rtk passthrough

Run rtk subcommands through MCP to filter output and save 60-90% tokens.

Tool: mcp__supercli__rtk____
Arguments: { "_args": "git status" }

Pre-allow Tools (optional)

Add to ~/.claude/settings.json to skip per-call permission prompts:

{
  "permissions": {
    "allow": [
      "mcp__supercli__skills_match",
      "mcp__supercli__rtk____",
      "mcp__supercli__rtk_analytics_gain",
      "mcp__supercli__yek_serialize_run",
      "mcp__supercli__yek_tree_show",
      "mcp__supercli__yek____",
      "mcp__supercli__agentmemory-cli_memory_save",
      "mcp__supercli__agentmemory-cli_memory_search",
      "mcp__supercli__agentmemory-cli_memory_list",
      "mcp__supercli__agentmemory-cli____"
    ]
  }
}

Tool Naming Convention

• Lockfile commands: mcp__supercli__<ns>_<res>_<act> (dots → underscores)
  • e.g. rtk._._ → mcp__supercli__rtk____
  • e.g. agentmemory-cli.memory.search → mcp__supercli__agentmemory-cli_memory_search
• Built-in tools: mcp__supercli__<name> (dots → underscores)
  • e.g. skills.match → mcp__supercli__skills_match

How It Works

1. MCP client spawns sc-machin mcp serve as a subprocess
2. Client sends initialize → server responds with protocol version + capabilities
3. Client sends tools/list → server returns all lockfile commands + built-in tools
4. Client sends tools/call → server executes and returns result

The server auto-prepends ~/.local/bin to PATH (MCP clients pass sanitized environments that omit user-level bin dirs).

Troubleshooting

• "rtk: not found" — already handled by PATH fix; if it persists, ensure rtk is in ~/.local/bin/
• Tool not in list — run sc-machin commands --json to verify the command is in the lockfile
• Permission denied — add the tool to permissions.allow in settings.json
• Connection failed — verify the binary path is absolute and executable