c-two 0.4.10

C-Two is a resource-RPC framework that enables resource-oriented classes to be remotely invoked across different processes or machines.

C-Two Python SDK

This directory contains the Python package for C-Two.

Development

Run development commands from the repository root.

Prerequisites:

• Python 3.10 or newer
• Python 3.12 for standard local development
• Python 3.14.3t when testing free-threading support
• Rust toolchain
• uv

Install dependencies and build the Python native extension. This also compiles the required Rust core crates; no separate Rust prebuild step is needed:

uv sync

Rebuild the native extension after changing Rust code:

uv sync --reinstall-package c-two

Relay-dependent tests and examples require the standalone c3 binary. From a source checkout, build and link it before running relay flows:

python tools/dev/c3_tool.py --build --link

The Python SDK does not embed or start a relay server. Start the standalone Rust relay with c3 relay, Docker Compose, or orchestration such as Kubernetes, then point Python code at its relay anchor with C2_RELAY_ANCHOR_ADDRESS or cc.set_relay_anchor(). The anchor is used for registration and name resolution. Remote HTTP calls still use the resolved route's relay_url directly, and local direct IPC is selected only for a loopback/local anchor. Relay-aware clients preflight routes before the first call and re-resolve structured stale-route responses; set C2_RELAY_ROUTE_MAX_ATTEMPTS to tune the maximum route acquisition attempts (default 3, valid range 1..=32, 0 is treated as 1). Ambiguous data-plane failures are not replayed.

Run the Python SDK tests:

C2_RELAY_ANCHOR_ADDRESS= uv run pytest sdk/python/tests -q --timeout=30

Run Rust core checks when validating shared native runtime changes:

cargo test --manifest-path core/Cargo.toml --workspace

For CLI build, link, and test commands, see ../../cli/README.md.

Examples

Python examples live under ../../examples/python/:

uv sync --group examples
uv run python examples/python/local.py

Relay examples also need a running standalone relay, for example:

python tools/dev/c3_tool.py --build --link
c3 relay --bind 127.0.0.1:8080

Benchmarks

Python-specific benchmarks live in benchmarks/:

C2_RELAY_ANCHOR_ADDRESS= uv run python sdk/python/benchmarks/segment_size_benchmark.py