Cryochamber

Cryochamber is a hibernation chamber for AI agents (Claude, OpenCode, Codex, Pi, Kimi Code). It hibernates an agent between sessions and wakes it at the right time — not on a fixed schedule. The agent reads its plan, completes a task, and decides for itself when to wake next. That lets AI agents run tasks that span days, weeks, or even years, like interstellar travelers in stasis.

Why not cron?

Cron wakes on a fixed schedule, whether or not there is anything to do. Cryochamber hands the scheduling decision to the agent:

• It saves tokens. A cron-driven agent burns a full session on every tick, even when nothing has changed. A cryochamber agent sleeps until there is a reason to wake — a TODO it scheduled, or a message in its inbox.
• It saves your brain. With cron, a human has to guess the right schedule up front: too fast wastes money, too slow misses things. Here the agent reasons about the situation — a deadline that slipped, a review waiting on the author, a chess opponent’s pace — and picks its own next wake.
• It handles emergencies. When something demands attention, the agent can schedule a wake minutes out, and an inbox message can wake it immediately. Cron cannot speed up when it matters.

Get running in two minutes

Platform support: macOS and Linux only.

cargo install cryochamber
mkdir my-chamber && cd my-chamber
cryo init          # scaffold plan.md and cryo.toml (or let the make-plan skill guide you)
cryo start         # start the daemon, installed as an OS service
cryohub start      # open the printed dashboard URL in your browser

Then edit plan.md to describe the agent’s goal and tasks. Runnable example chambers (mr-lazy, chess-by-mail, and more) live in examples/chambers/ on GitHub.

Watch it work

cryohub start    # prints the local dashboard URL — open it in your browser

Cryohub is the local web dashboard: chamber status, message history, TODOs, notes, log tail, and lifecycle controls, plus a send widget to talk to the agent. For remote messaging from the web or your phone, bridge the chamber to Zulip with cryo-zulip.

What a chamber guarantees

• Every wake produces a visible message. If the agent exits without replying, the daemon writes a fallback message — a session is never silent.
• Every inbox message is answered. Even if the agent crashes mid-session, the sender still gets a reply.
• Every TODO is honoured. Failed sessions are rescheduled as visible retry attempts with exponential backoff.
• Nothing is consumed twice. Claimed messages and TODOs never silently become pending again.

Next

• How it works — a five-minute walkthrough: the chamber files and the session loop.
• CLI reference — every cryo, cryohub, cryo-agent, and cryo-zulip command.
• Configuration — every cryo.toml and cryohub.toml field.