Bloom Filters for AI Agents: The Small Cache Trick That Saved My Retrieval Pipeline

Bloom filters felt like a purely academic data structure—until an agent pipeline started repeating work. At that point, they became immediately practical. Problem The system needed a fast, low-cost way to check whether something had probably been seen before. Not certainty. A strong enough signal to avoid redundant work. Failure Mode The agent repeatedly: revisited identical document IDs re-triggered the same tool calls reprocessed items already handled minutes earlier This created: unnecessary