Accordion

Accordion is a free and open-source desktop application that makes an AI agent's context window visible and steerable. Instead of silently dropping old conversation when the context fills up, Accordion displays the entire history as a list of sections—one per turn—that you can fold into summaries or expand back to full detail. Nothing is ever thrown away; every action is reversible. Built primarily for developers using agentic coding assistants like Claude Code, Accordion lets three parties operate the same context: you, the agent, and an automated Conductor. You can manually fold, unfold, pin sections, or peek inside folded sections without affecting the agent's view. The agent can unfold or pin sections it needs but never decides what to discard. The Conductor automatically manages the context budget between turns, folding cold sections and unfolding relevant ones. Accordion reserves a protected working tail of the newest ~20k tokens (configurable) that never gets folded, ensuring the agent's recent reasoning is always intact. The tool also provides a token-count view so you can monitor usage in real time. It runs on macOS (Apple Silicon and Intel), Windows, and Linux, and is licensed under MIT. What makes Accordion unique is its philosophy that context is a view, not a store. By keeping a complete record and only controlling what the agent sees, it avoids lossy compression and irreversible compaction, giving you total control over your agent's memory.