Universal Rust wrapper for CLI AI agents (Claude Code, Codex, Gemini). PTY mirror and pipe/NDJSON modes with tokio broadcast fan-out.

gate4agent

Universal Rust transport library for CLI AI agents. Spawn, stream, resume — for four different CLI agents through one unified API.

Not a harness. Not a sandbox. gate4agent is the thin wiring layer between your Rust app and the CLI agent's subprocess: spawn the binary, write the prompt, read structured events, resume by session id. That's it.

Supported CLI tools

Transport classes:

• Pipe: spawn the CLI directly, read NDJSON over stdout
• PTY: spawn inside a pseudo-terminal, scrape the screen with vt100 (for agents without structured output)
• ACP (Agent Client Protocol): spawn the CLI in ACP mode, communicate via bidirectional JSON-RPC 2.0 over stdio. Multi-turn sessions, structured events, agent→host callbacks (fs, terminal, permissions).

Quick start

use gate4agent::{CliTool, SessionConfig, AgentEvent, PipeSession, PipeProcessOptions};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let config = SessionConfig {
        tool: CliTool::ClaudeCode,
        working_dir: std::env::current_dir()?,
        env_vars: vec![],
        name: None,
    };
    let session = PipeSession::spawn(config, "Say hello in 3 words", PipeProcessOptions::default()).await?;

    let mut rx = session.subscribe();
    while let Ok(event) = rx.recv().await {
        match event {
            AgentEvent::Text { text, .. } => p