Function codex_create 

pub fn codex_create(
    cwd: &Path,
    prompt: &str,
    from_name: &str,
    yolo: bool,
    output_path: &Path,
    timeout: Option<Duration>,
    agent_self: Option<&str>,
    model: Option<&str>,
    reasoning_effort: Option<&str>,
    add_dir: Option<&str>,
) -> Result<CodexResult, CodexAskError>

Spawn codex exec --json -C <cwd> ... and parse the JSONL stream. agent_self is the name of this agent (injected into spawn env for nested fno agents ask attribution).