ACP: protocolVersion type mismatch with Gemini CLI (--acp)

[xqicxx]

Bug

When using acpx with Gemini CLI (gemini --acp), the ACP handshake fails because of a protocolVersion type mismatch.

Error

Gemini CLI returns:

{
  "error": {
    "code": -32603,
    "message": "Internal error",
    "data": [{
      "expected": "number",
      "code": "invalid_type",
      "path": ["protocolVersion"],
      "message": "Invalid input: expected number, received string"
    }]
  }
}

Root Cause

• acpx sends: "protocolVersion": "1.0" (string)
• Gemini CLI expects: "protocolVersion": 1 (number)

Reproduce

echo '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"1.0","capabilities":{},"clientInfo":{"name":"acpx","version":"0.3.1"}}}' | gemini --acp

Environment

• acpx: 0.3.1
• Gemini CLI: 0.34.0

Expected

acpx should send protocolVersion as a number to comply with Gemini CLI's ACP implementation.

Notes

• Codex and Claude work fine with acpx
• Gemini CLI ACP docs: https://geminicli.com/docs/cli/acp-mode/
• ACP spec may allow both types, but Gemini CLI strictly requires number