{"id":23182,"library":"ucxx-cu12","title":"ucxx (CUDA 12)","description":"Python bindings for the Unified Communication X library (UCX), optimized for CUDA 12 memory operations (e.g., UCX_CUDA_COPY_ASYNC). Version 0.49.0 is current. Release cadence: aligns with RAPIDS releases (~monthly). This package replaces `ucxx` for systems with CUDA 12.x (requires CUDA 12.2+).","status":"active","version":"0.49.0","language":"python","source_language":"en","source_url":"https://github.com/rapidsai/ucxx","tags":["ucx","cuda","gpu","communication","rapids","distributed"],"install":[{"cmd":"pip install ucxx-cu12","lang":"bash","label":"Install from PyPI"},{"cmd":"conda install -c rapidsai -c conda-forge ucxx-cu12","lang":"bash","label":"Install from conda"}],"dependencies":[{"reason":"UCX requires NUMA libraries (libnuma) at runtime for topology-aware communication.","package":"numa","optional":false},{"reason":"CUDA runtime and driver libraries are required for UCX CUDA support; replaced numba-cuda in v0.49.0.","package":"cuda-core (>=12.2)","optional":false},{"reason":"Common integration with RAPIDS cuDF or CuPy for GPU arrays.","package":"cudf or cupy","optional":true}],"imports":[{"wrong":"from ucxx import UCXWorker","symbol":"UCXWorker","correct":"from ucxx.core import UCXWorker"}],"quickstart":{"code":"import os\n# Set environment variables for UCX (optional but recommended)\nos.environ.setdefault('UCX_PROTO_ENABLE', 'y')\nos.environ.setdefault('UCX_TLS', 'tcp,cuda_copy')\n\nfrom ucxx import UCXListener, UCXWorker, get_config\n\n# Print UCX configuration to verify the environment\nprint(get_config())","lang":"python","description":"Basic import and environment setup. Always set UCX_TLS to include 'cuda_copy' for GPU transfers. Use `os.environ.setdefault` to avoid overriding user settings."},"warnings":[{"fix":"Ensure your code uses cuda-core and does not depend on numba-cuda internally. Update any direct imports from numba.cuda.","message":"In v0.49.0, the numba-cuda runtime dependency was replaced with cuda-core. Code relying on numba-cuda integration may break.","severity":"breaking","affected_versions":">=0.49.0"},{"fix":"Upgrade to CUDA 12.2 or later. If you need CUDA 11, stay on ucxx-cu11 (or ucxx <0.47).","message":"In v0.47.0, CUDA 12.2+ became mandatory. Older CUDA 11.x installations are no longer supported.","severity":"breaking","affected_versions":">=0.47.0"},{"fix":"Replace `import ucp` with `import ucxx` and adjust imports (e.g., `ucp.get_worker()` -> `ucxx.get_worker()`).","message":"The `ucp` module (from the early `ucx-py` package) is deprecated. Import from `ucxx` instead.","severity":"deprecated","affected_versions":"all"},{"fix":"Set environment variable `UCXX_SKIP_PYTHON_FUTURE_NOTIFIER=1` or upgrade to ucxx v0.49.0+ which automatically handles this.","message":"Python 3.13.12+ introduced behavior changes that may cause hangs with Python future notifiers. Skipping future notifiers is now recommended.","severity":"gotcha","affected_versions":">=0.49.0 with Python 3.13.12+"},{"fix":"Set `UCX_TLS=tcp,cuda_copy` before importing ucxx. Also ensure `UCX_PROTO_ENABLE=y`.","message":"UCX_TLS environment variable must include 'cuda_copy' for GPU transfers; otherwise UCX may fall back to CPU-only communication.","severity":"gotcha","affected_versions":"all"}],"env_vars":null,"search_vec":"'0.49.0':25 '12':3,16,43 '12.2':47 'align':30 'async':23 'bind':5 'cadenc':29 'communic':9,51 'copi':22 'cuda':2,15,21,42,46,49 'current':27 'distribut':53 'e.g':19 'gpu':50 'librari':11 'memori':17 'month':34 'oper':18 'optim':13 'packag':36 'python':4 'rapid':32,52 'releas':28,33 'replac':37 'requir':45 'system':40 'ucx':12,20,48 'ucxx':1,38 'unifi':8 'version':24 'x':10,44","created_at":"2026-05-01T06:02:51.148908+00:00","updated_at":"2026-05-01T06:02:51.148908+00:00","problems":{"verify_error":"Traceback (most recent call last):\n  File \"<string>\", line 1, in <module>\nImportError: cannot import name 'UCXWorker' from 'ucxx.core' (/tmp/tmp6qmrql0n/venv/lib/python3.12/site-packages/ucxx/core.py)"},"ecosystem":"pypi","meta_description":null,"install_score":null,"quickstart_score":null,"quickstart_tag":null,"pypi_latest":"0.50.0","cli_name":"","cli_version":null,"type":"library","homepage":null,"github":"https://github.com/rapidsai/ucxx","docs":null,"changelog":null,"pypi":"https://pypi.org/project/ucxx-cu12/","npm":null,"openapi_spec":null,"status_page":null,"smithery":null,"categories":["data","ai-ml"],"base_url":null,"auth_type":null,"provenance":{"verified_status":"import_fail","verified_at":"2026-07-03","last_verified":"2026-07-03","next_check":"2026-07-10","install_tag":null}}