supercli: Skill for Claude Code

Supercli MCP Development

Work on MCP (Model Context Protocol) features in supercli including adapter implementation, SSE streaming support, and server integration.

MCP Adapter Architecture

The MCP adapter (cli/adapters/mcp.js) supports multiple transport modes:

Transport Modes

1. HTTP/SSE MCP: HTTP-based MCP servers with SSE streaming
2. Stdio MCP with Daemon: Local stdio MCP servers routed through daemon
3. Stdio MCP Direct: Direct stdio calls (may have compatibility issues)

Key Components

• execute(): Main entry point, routes to appropriate transport
• callHttpMcpTool(): HTTP/SSE MCP handler with JSON-RPC support
• parseSseResponse(): SSE event parser
• callStdioTool(): Direct stdio execution
• stdioCallToolJsonRpc(): Stdio JSON-RPC protocol handler
• callDaemonTool(): Daemon-routed stdio calls

HTTP/SSE Implementation

Request Format

Uses JSON-RPC 2.0 format for HTTP MCP calls:

{
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "name": toolName,
    "arguments": input
  },
  "id": 1
}

Headers

Must include both content types for SSE negotiation:

{
  "Content-Type": "application/json",
  "Accept": "text/event-stream, application/json"
}

SSE Response Parsing

Parses Server-Sent Events format:

• Lines starting with event: define event type
• Lines starting with data: contain event data
• Empty lines terminate events
• Accumulates chunks and returns final result

Auto-detection

Automatically detects SSE responses via Content-Type header and falls back to JSON if not SSE.

Stdio MCP with Daemon

Configuration

{
  "adapterConfig": {
    "server": "mcp-server-name",
    "tool": "tool-name",
    "stateful": true,
    "timeout_ms": 60000
  }
}

Daemon Client

• File: cli/mcp-daemon-client.js
• Functions: callDaemonTool(), listDaemonTools()
• Maintains persistent sessions for stateful MCP servers
• Daemon runs on CLI side (not server) - starts on-demand when first command with stateful: true is executed via CLI
• Runs as detached background process with Unix socket at ~/.supercli/mcp-daemon.sock
• Persists across command executions to maintain MCP server sessions
• Better for long-running stdio MCP servers