KVShareArena benchmarks KV-cache reuse beyond exact prefixes

KVShareArena scores methods that repair KV caches for non-exact-prefix reuse (RAG-retrieved chunks, multi-agent reports) on the fraction of the no-cache-to-full-recompute gap recovered, while computing compute/memory/per-request latency. Key findings: position correction alone suffices unless the query requires multiple sources; paid methods (re-encoding / training) recover 1/2-2/3 of the gap; uncorrected reuse can be worse than no cache; and trained adapters lose more quality than training-free methods when reusing across model checkpoints. Shipped as a pip package with automated submission and a public leaderboard.

This method family (ReCache, CacheBridge, position repair) has been growing all month without a fair comparison. KVShareArena gives it a leaderboard and two decision rules: don't reuse uncorrected caches across queries needing multiple sources, and prefer training-free repair when crossing checkpoints.