gate4agent

Universal Rust wrapper for CLI AI agents (Claude Code, Codex, Gemini).

Two transport modes:

• PTY mirror: Spawns agent in a real PTY, captures raw output, vt100 screen parsing
• Pipe mode: claude -p --output-format stream-json, plain OS pipes, NDJSON event streaming

Both modes produce AgentEvent values on a tokio::sync::broadcast channel.

Supported CLI tools

Quick start

use gate4agent::pipe::{PipeSession, PipeProcessOptions, ClaudeOptions};
use gate4agent::{AgentEvent, SessionConfig};

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let config = SessionConfig::default();
    let options = PipeProcessOptions {
        claude: ClaudeOptions {
            model: Some("claude-sonnet-4-20250514".into()),
            ..ClaudeOptions::default()
        },
        ..PipeProcessOptions::default()
    };

    let session = PipeSession::spawn(config, "Hello, Claude!", options).await?;
    let mut rx = session.subscribe();

    loop {
        match rx.recv().await? {
            AgentEvent::PipeText { text, .. } => print!("{text}"),
            AgentEvent::PipeSessionEnd { .. } => break,
            _ => {}
        }
    }

    Ok(())
}

Architecture

gate4agent/
├── src/
│   ├── lib.rs          — Library root, re-exports
│   ├── types.rs        — AgentEvent, SessionConfig, CliTool
│   ├── error.rs        — Error types
│   ├── cli/            — Per-tool output parsers (Claude, Codex, Gemini)
│   ├── parser/         — VTE + screen parsers for PTY mode
│   ├── ndjson/         — NDJSON stream parser for pipe mode
│   ├── pty/            — PTY session (PtyWrapper, PtySession)
│   ├── pipe/           — Pipe session (PipeProcess, PipeSession)
│   └── detection/      — Rate limit detection

Features

• Multi-turn sessions: --resume <session_id> for Claude Code continuity
• System prompt injection: --append-system-prompt for custom instructions
• Rate limit detection: Pattern-based detection of session/daily/weekly limits
• Cross-platform: Windows (ConPTY) and Unix (POSIX PTY) support
• Zero-copy streaming: tokio broadcast channels, no buffering

Prerequisites

At least one CLI agent must be installed:

• Claude Code: npm install -g @anthropic-ai/claude-code
• Codex CLI: npm install -g @openai/codex
• Gemini CLI: npm install -g @google/gemini-cli

Support the Project

If you find this tool useful, consider supporting development:

License

MIT