Crate cap_rs 

cap-rs — Rust reference implementation of the CAP (CLI Agent Protocol).

See https://cap-protocol.org for the protocol specification.

Layout

• core — protocol types (events, frames, capabilities, manifest). Always available, no IO dependencies.
• driver — backends that drive an actual CLI agent. Each backend is gated behind a feature flag.

Quick start

[dependencies]
cap-rs = { version = "0.1", features = ["stream-json"] }

use cap_rs::driver::stream_json::ClaudeCodeDriver;
use cap_rs::core::{ClientFrame, Content};

let mut driver = ClaudeCodeDriver::spawn(std::env::current_dir()?).await?;
driver.send(ClientFrame::Prompt {
    content: vec![Content::Text("What is 2 + 2?".into())],
}).await?;

while let Some(event) = driver.next_event().await {
    println!("{event:?}");
}

Modules

core

Core protocol types — events, frames, content blocks, usage.

driver

Driver backends — concrete implementations that drive a CLI agent.

Constants

CRATE_NAME

Crate name (build-time constant).

CRATE_VERSION

Crate version (build-time constant).

PROTOCOL_VERSION

CAP protocol version targeted by this crate.