Show HN: KV Marketplace – share LLM attention caches across GPUs like memcached

Hi all - this is a small research prototype I built to explore cross-GPU reuse of transformer attention states.

When inference engines like vLLM implement prefix/KV caching, it's local to each replica. LMCache recently generalized this idea to multi-tier storage.

KV Marketplace focuses narrowly on the GPU-to-GPU fast path: peer-to-peer prefix reuse over RDMA or NVLink. Each process exports completed prefix KV tensors (key/value attention states) into a registry keyed by a hash of the input tokens and model version. Other processes with the same prefix can import those tensors directly from a peer GPU, bypassing host memory and avoiding redundant prefill compute.

Under optimistic conditions (perfect prefix importing), the prototype shows about a 15% reduction in latency and throughput gains without heavy tuning. The code is intentionally minimal (no distributed registry, eviction, or CPU/disk tiers yet) but it's a prototype of "memcached for attention."

I thought others exploring distributed LLM inference, caching, or RDMA transports might find the repo useful or interesting.