AI coding agents can't feel when they're stuck. They'll retry the same broken fix five times because they can see each error but not the pattern. Metacog is a Claude Code hook that watches for these loops, and six other failure modes, silently. When things go wrong, it nudges the agent to reflect. When problems resolve, it learns what fixed them. Most memory systems prune rules that stop firing. Metacog treats that silence as proof the rule worked. Zero dependencies. One-command install.