# A2CR Guide
A2CR saves AI work state as a WorkBaton so another AI window, model, or MCP-capable client can resume the work.
A2CR is not an AI. It is the baton that lets AI agents hand work to one another.
Let your AI read it:
- Show the AI agent guide to the AI agent you already use and ask it to explain A2CR.
- The guide is written for agents, so it can turn the app's role, limits, and setup into plain guidance for your situation.
Important points:
- WorkBaton is client-encrypted only.
- A2CR does not accept plaintext WorkBaton bodies.
- The local stdio MCP wrapper encrypts before upload, and A2CR stores and returns ciphertext only.
- Direct remote HTTP MCP saving is disabled for WorkBaton.
- The local client key is managed by the user, not by the service administrator.
- If the local client key is lost, old client-encrypted slots cannot be recovered by A2CR.
- Slots saved after creating a new local client key can be read with that new key, but old slots still need the old key.
Related pages:
- AI agent guide: https://a2cr.app/en/agent-guide
- Japanese guide: https://a2cr.app/guide
- MCP service URL: https://a2cr.app/mcp
Compression / summarization vs A2CR / WorkBaton:
- Compression and summarization shorten a long conversation.
- A2CR / WorkBaton passes a state that lets the next AI resume work.
- Compression and summarization target history inside that chat.
- A2CR / WorkBaton targets another chat, another AI, or another tool.
- Compression and summarization output summary text.
- A2CR / WorkBaton outputs work state such as goal, current_state, next_action, and blockers.
- Compression is a diet for a conversation log. A2CR is a baton for work state.
Sub-agents vs A2CR:
- Sub-agents divide work inside the same environment.
- A2CR carries the environment itself forward.
- Sub-agents are effective inside that chat and its parent agent.
- A2CR can work across ChatGPT, Claude, Codex, Cursor, Roo, and local LLMs.
- Sub-agent state sharing depends on the parent agent's context.
- A2CR stores state in an external temporary relay DB and expires it by TTL.