{
  "id": "agent-host-transport:stdio",
  "_kind": "AgentHostTransport",
  "_file": "compute/agent-host-transports/stdio.yaml",
  "_cluster": "compute",
  "attributes": {
    "displayName": "stdio",
    "kind": "stdio",
    "description": "Plain stdin/stdout pipe to the agent process. The simplest invocation\nshape; used by CI runners, the babysitter harness, and most CLI tools\nwhen they spawn an agent for a single task.\n",
    "inboundMessageFormat": "Per-agent. Common patterns:\n  - Single JSON object on stdin, EOF terminates the request (one-shot\n    mode used by most CI invocations).\n  - Newline-delimited JSON (JSONL) when the host streams multiple\n    turns / tool results into the agent across a single session.\n  - Free-form text prompt on stdin (legacy / interactive REPL agents).\nThe agent's CLI surface (flags, env vars) configures which shape is\nexpected; no cross-vendor standard exists. Agent-specific stdin\nformats are recorded on the AgentVersion node via per-edge\nevidence rather than duplicated on this transport node.\n",
    "outboundMessageFormat": "Per-agent. Common patterns:\n  - Newline-delimited JSON (JSONL) event stream on stdout, one event\n    per line (e.g. Claude Code `--output-format stream-json`,\n    Codex CLI session events).\n  - Single JSON document on stdout for one-shot invocations.\n  - Plain text / ANSI-coloured output for interactive agents.\nstderr is reserved for human-readable diagnostics and is NOT part of\nthe structured wire surface.\n",
    "signalForwarding": "POSIX signals on the child process:\n  - SIGINT  — interrupt the current turn (graceful cancel; agent should\n    flush partial output and return).\n  - SIGTERM — request a clean shutdown.\n  - SIGKILL — last-resort termination (no cleanup).\nOn Windows, hosts typically use `GenerateConsoleCtrlEvent(CTRL_C_EVENT)`\nor `TerminateProcess`. Closing stdin (EOF) is also commonly used to\nsignal end-of-input without sending a signal.\n",
    "ptySemantics": "Plain stdio — the agent is invoked with anonymous pipes for\nstdin/stdout/stderr; `isatty()` returns false on all three. ANSI\ncolour codes, prompt redraws, and raw-mode keystrokes are not\navailable. Hosts that need TTY behaviour use\n`agent-host-transport:stdio-pty` instead.\n"
  },
  "outgoingEdges": [
    {
      "from": "agent-host-transport:stdio",
      "to": "agentVersion:claude:ge-0-0-0",
      "kind": "used_by"
    },
    {
      "from": "agent-host-transport:stdio",
      "to": "agentVersion:codex:ge-0-119-0",
      "kind": "used_by"
    }
  ],
  "incomingEdges": []
}