agent-harness 0.4.0

//! Drive an external **ACP agent** (OpenCode, Gemini, Goose, …) over the Agent
//! Client Protocol and stream the same normalized [`RunEvent`]s as every other
//! harness — agent-harness spawns the agent and relays its session.
//!
//! ```text
//! cargo run --example run_acp --features acp   # needs `opencode` on PATH
//! ```

use harness::{AcpHarness, Harness, HarnessError, RunEvent, RunMode, RunRequest, RunTuning};

fn main() -> Result<(), HarnessError> {
    // OpenCode over ACP — spawns `opencode acp` and relays its session stream.
    // Point at any other ACP agent with `AcpHarness::custom`, e.g.:
    //   AcpHarness::custom(AcpHarnessConfig { id: "gemini".into(),
    //       display_name: "Gemini".into(), command: "gemini".into(),
    //       args: vec!["--experimental-acp".into()] })
    let agent = AcpHarness::opencode();

    let (_handle, rx) = agent.run_channel(RunRequest {
        run_id: "demo".into(),
        prompt: "In one sentence, what is the Agent Client Protocol?".into(),
        cwd: None,
        mode: RunMode::Ask,
        // ACP carries no model; opencode takes a launch-time one out-of-band.
        // Set `tuning.model` (e.g. "opencode/big-pickle") and it's written to a
        // temp config at spawn. `default()` ⇒ the agent's own default.
        tuning: RunTuning::default(),
        resume: None,
        attachments: Vec::new(),
    })?;

    // One normalized stream, whichever ACP agent produced it.
    for ev in rx {
        match ev {
            RunEvent::Text { delta, .. } => print!("{delta}"),
            RunEvent::Thinking { delta, .. } => eprint!("{delta}"),
            RunEvent::ToolStart { title, .. } => eprintln!("\n[tool] {title}"),
            RunEvent::Error { message, .. } => eprintln!("\n[error] {message}"),
            RunEvent::Exited { .. } => break,
            _ => {}
        }
    }
    Ok(())
}