Protocol Like MCP, codex app-server supports bidirectional communication using JSON-RPC 2.0 messages (with the "jsonrpc":"2.0" header omitted on the wire). Supported transports: stdio (--listen stdio://, default): newline-delimited JSON (JSONL). websocket (--listen ws://IP:PORT, experimental): one JSON-RPC message per WebSocket text frame. In WebSocket mode, app-server uses bounded queues. When re

