Context Rotation for AI Coding Agents: What Happens When They Run Out of Memory

Your AI coding agent has been working for 20 minutes. The output quality drops. It starts repeating itself. It "forgets" a file it edited 5 minutes ago and makes conflicting changes. Then it prints something like "I've reached my context limit" and stops. Context exhaustion. Every developer running AI agents hits it. Most don't realize what's happening until the damage is done. What Context Exhaustion Looks Like AI agents have a fixed context window — the total amount of text they can "remember" in a single session. When they approach the limit, the symptoms are subtle before they're obvious: Early signs (easy to miss): Agent re-reads files it already read earlier in the session Suggestions contradict changes it made minutes ago Code quality degrades — more boilerplate, less precision Agent asks questions it already has the answer to Late signs (obvious but costly): Agent explicitly says it's hitting context limits Output becomes repetitive or circular Agent starts hallucinating functi