MCP server configuration in punch.toml

[humancto]

Problem

Punch has no way to configure MCP servers. Fighters cannot connect to external tools (Gmail, Calendar, Slack, GitHub, etc.).

Proposed Solution

Add [mcp_servers] section to punch.toml:

[mcp_servers.gmail]
command = "npx"
args = ["-y", "@anthropic-ai/mcp-server-gmail"]
transport = "stdio"

[mcp_servers.github]
command = "npx"
args = ["-y", "@modelcontextprotocol/server-github"]
transport = "stdio"
env = { GITHUB_TOKEN_ENV = "GITHUB_TOKEN" }

Requirements

• Parse [mcp_servers] in punch-types::config
• Support stdio transport (child process, JSON-RPC 2.0 over stdin/stdout)
• Support http transport (Streamable HTTP, per Nov 2025 MCP spec)
• Scoped env vars isolated to the server process
• Validate config on punch start with clear error messages