KV caches are a major bottleneck in long-context inference and long-form generation with large language models. Existing training-free eviction policies largely rely on proxy importance signals, such as attention mass, to decide which past tokens to retain. We argue that cache compression should instead preserve the predictive behavior of the full-cache model, retaining entries whose removal would substantially change the model’s output distribution. We propose Behavior-Preserving KV Cache Compression, a training-free framework that scores candidate evictions by estimating the compressed-cache logits induced by their removal and evaluating the resulting KL to the full-cache next-token distribution. Using pre-eviction forward statistics, the method avoids running separate masked forward passes for each candidate. Across diverse architectures and both prefill-time and generation-time compression, our method delivers substantial gains in downstream task quality over lightweight attention-based heuristics at matched retained-KV budgets, with the largest gains under aggressive compression. It achieves these gains with additional compression-time computation while retaining an end-to-end speedup over full-cache inference in our evaluated settings.

Concurrent multi-agent LLM systems increasingly rely on role-specialized Workers that act in parallel, but effective coordination depends not only on what Workers generate, but also on what task state each Worker observes before generating. Existing systems usually fix this observation interface through workflow rules, retrieval heuristics, or full-history sharing, so information flow cannot adapt as task state and feedback evolve. We introduce Dynamic Context Allocation (DCA), which treats per-Worker observation control as a trainable coordination problem for a fixed-role team. An RL-trained Context Allocator maintains a bounded Context Board and decides before each round which evolving task-state entries should be retained, revised, removed, or exposed to each Worker, rather than learning agent selection, execution order, or workflow topology. We evaluate DCA on cooperative code generation, Customer Relationship Management (CRM) lead qualification, and MultiWebGen, a new benchmark for multi-agent full-stack web development. Across these settings, DCA improves over fixed-protocol coordination and fixed-context multi-agent RL baselines, and it outperforms all evaluated frontier single-agent LLMs on CRM lead qualification despite using smaller role-specialized Workers.