ccht for Python

The same Rust conversation model used by ccht's native and Wasm consumers, available as pip install ccht. Python 3.10 or newer is required.

from ccht import Conversation

chat = Conversation("creator")
changed = chat.apply_event({
    "version": 1,
    "conversation_id": "creator",
    "request_id": "turn-1",
    "sequence": 1,
    "event": {
        "kind": "update",
        "update": {
            "sessionUpdate": "agent_message_chunk",
            "content": {"type": "text", "text": "Hello"},
        },
    },
})
assert changed
assert chat.snapshot()["turns"][0]["text"] == "Hello"

Conversation.apply_event() accepts a JSON string or mapping and returns whether it changed the model. Replayed events return False. A wrong conversation, sequence gap, invalid envelope, or event after completion raises ConversationError (a ValueError subclass) without changing the state. snapshot() returns a detached dictionary; snapshot_json() returns its JSON. Tool calls, permissions, thought and non-text content retain the same wire contract as the Rust and Wasm packages. Sequence numbers start at one per request.

This package binds the portable model through PyO3. It does not expose the Rust native process host. Your application connects to an authorized host, delivers its ccht events, and owns UI, prompts, persistence, transport and authorization. Use the Rust ccht::native API to host installed Codex, Claude or OpenCode ACP executables. No agent, credentials, provider HTTP client or paid fallback is included in the Python package.

The first binary wheel targets Linux x86-64 (glibc 2.34 or newer) with CPython's stable ABI. Other platforms build the source distribution with a compatible Rust compiler, C linker, Python development headers and the declared maturin build backend. Only platforms exercised by release CI are claimed as tested.

License and source replacement

ccht is LGPL-3.0-only WITH LGPL-3.0-linking-exception. Both LGPL and GPL texts and upstream notices accompany the distributions. The wheel includes its corresponding source distribution at ccht/source/ccht-<version>.tar.gz; PyPI also serves it separately. It contains the binding, exact published Rust ccht source, every locked Cargo dependency and Cargo's vendor configuration. No application source is part of this kit.

To rebuild and replace the extension, extract that archive, make your changes, then run python -m pip wheel --no-deps . and install the resulting wheel into your application's environment. Cargo can build without registry access using the supplied vendor directory (CARGO_NET_OFFLINE=true). Python build tools and the compiler are separate prerequisites. CI also rebuilds the extracted source with an empty Cargo cache and runs the same independent consumer against the replacement. This proves source replacement, not byte-identical compilation.

Release builds use maturin's ABI audit with the actual Rust target. On Nix, the release check removes the extension's build-host RPATH with patchelf and repacks it with the standard wheel tool before testing. This changes no ABI tags or bundled source. Build the source directly on your own platform to use its normal linker configuration.

Keep the notices, corresponding source and users' replacement rights when distributing applications with ccht. Product licensing and installation must permit the applicable LGPL replacement/debugging rights; consult the included license texts for the actual terms.