# Failure and recovery What survives when something goes wrong, and what doesn't. ccr-cloud is built so that **dropped connections and control plane restarts don't lose task activity**. It does **not** make a task's actions exactly-once, and a crashed task loses what it hadn't reported yet. ## How delivery works - **Activity from a task** (Claude's messages, tool calls, approval requests, status) is numbered by the task's runner and kept in its memory until the control plane confirms it has written it to the task's log. After a reconnect, the runner resends everything unconfirmed, and the control plane skips numbers it already has. - **Your actions** (follow-ups, approvals, interrupts) are saved in the task's record first, then sent until the runner confirms receipt. The runner ignores repeats during one run. - **The app** replays the task's log from where it left off when you reconnect. ## What happens when… | Situation | Effect on the task | |---|---| | Your browser, phone or SSH tunnel disconnects | None. The task keeps running; the app catches up when you reconnect. | | The control plane restarts or is updated | Tasks keep running. Their runners reconnect and resend unconfirmed activity; your saved actions are delivered. Open approvals stay open. | | The connection between a runner and the control plane drops | Same as a restart: activity and actions are resent when it reconnects. | | The runner or Claude Code crashes or exits | The task becomes **Stopped** or **Failed**, within about 10 seconds if nothing reports it. Open approvals are cancelled. See [below](#what-a-crash-can-lose). | | You select **Interrupt turn** or **Stop session** | Claude stops the current turn or exits. Open approvals are cancelled. | | The server reboots | Everything stops. Restart the service, then resume tasks; see [Operate your server](https://ccr-cloud.uubright.com/docs/operations/#after-a-reboot). | **Resume** restarts the task's runner, which continues Claude Code's saved conversation in the same workspace. ## What a crash can lose When a runner or Claude Code process dies unexpectedly: - **Unreported activity.** Anything the runner hadn't yet had confirmed by the control plane is lost with it. On a normal exit, the runner waits up to 10 seconds to deliver everything first. - **Follow-ups waiting for the current turn.** The runner holds them until Claude finishes the turn. If it dies first, they're lost; send them again after resuming. - **Open approvals.** They're cancelled and shown as **Cancelled**. Claude never got a decision, so it may ask again after you resume. - **The tool call in progress.** It isn't retried. Its side effects, such as edited files or a command that already ran, stay as they were. Check the workspace before asking Claude to continue. ## What isn't guaranteed - **Exactly-once actions.** A follow-up or decision can, rarely, be delivered twice: if a runner restarts after receiving it but before its confirmation reaches the control plane, the next run receives it again. A decision only applies to the exact request it answers, and a new run starts with no open requests, so a repeated decision can't approve something else; it fails harmlessly. - **Exactly-once tool effects.** ccr-cloud records what Claude did; it can't undo or deduplicate commands. That's why approvals show the exact command. - **Power-loss durability.** Logs are written as each event arrives but aren't forced to disk. A power failure or kernel crash can lose the last moments of activity. - **Partial tool output.** Tool output is recorded when the tool finishes, not while it runs, so a long command shows nothing until it ends. ## Approvals - A decision applies only to the one request it answers, in that task. - A request can be answered once. A second answer, from another device or from Discord, is rejected. - Interrupting, stopping, restarting or crashing a task cancels its open requests. - **Allow once** runs the tool with exactly the input you reviewed. ## Next steps - [Operate your server](https://ccr-cloud.uubright.com/docs/operations/) - [How it works](https://ccr-cloud.uubright.com/docs/how-it-works/) - [Troubleshooting](https://ccr-cloud.uubright.com/docs/troubleshooting/)