nccl-communication
NVIDIA Collective Communications Library integration for multi-GPU operations. Initialize NCCL communicators, execute collective operations, configure communication topologies, profile collective performance, and support RCCL for AMD compatibility.
npx skills add a5c-ai/babysitter --skill nccl-communication --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# nccl-communication You are **nccl-communication** - a specialized skill for NVIDIA Collective Communications Library (NCCL) integration. This skill provides expert capabilities for multi-GPU collective operations. ## Overview This skill enables AI-powered multi-GPU communication including: - Initialize NCCL communicators - Execute all-reduce, all-gather, reduce-scatter operations - Configure ring and tree communication topologies - Handle multi-node NCCL communication - Profile collective operation performance - Optimize for NVLink vs PCIe topology - Integrate with CUDA streams for async collectives - Support RCCL for AMD GPU compatibility ## Prerequisites - CUDA Toolkit 11.0+ - NCCL 2.10+ - Multiple GPUs (for meaningful use) - MPI (for multi-node, optional) ## Capabilities ### 1. NCCL Initialization Initialize communicators: ```c #include <nccl.h> // Single-node multi-GPU initialization int numGPUs = 4; ncclComm_t comms[4]; int devs[4] = {0, 1, 2, 3}; ncclCommInitAll(comms, numGPUs, devs); // Per-rank initialization for MPI integration ncclUniqueId id; ncclComm_t comm; if (rank == 0) { ncclGetUniqueId(&id); } MPI_Bcast(&id, sizeof(id), MPI_BYTE, 0, MPI_COMM_WORLD); cudaSetDevice
- Overview
- Prerequisites
- Capabilities
- 1. NCCL Initialization
- 2. All-Reduce Operations
- 3. All-Gather Operations
- 4. Reduce-Scatter Operations
- 5. Broadcast and Reduce
- 6. Group Operations
- 7. Point-to-Point Communication
- 8. Topology Optimization
- 9. Multi-Node Setup
- 10. Performance Profiling
- Process Integration
Check GPU topology nvidia-smi topo -m Environment variables for optimization export NCCL_TOPO_FILE=/path/to/topo.xml export NCCL_GRAPH_FILE=/path/to/graph.xml Algorithm selection export NCCL_ALGO=Tree # Tree reduction export NCCL_ALGO=Ring # Ring reduction export NCCL_ALGO=CollnetDirect # NVSwitch direct Protocol selection
What does the nccl-communication skill do?
NVIDIA Collective Communications Library integration for multi-GPU operations. Initialize NCCL communicators, execute collective operations, configure communication topologies, profile collective performance, and support RCCL for AMD compatibility.
How do I install it?
Run `npx skills add a5c-ai/babysitter --skill nccl-communication --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From a5c-ai/babysitter, a repository with 1,642 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.