Runtime changelog, 29 October 2026
What shipped in Runtime Cloud on 29 October 2026: forks start on another server when the source's server is full; and a sandbox that stops responding is reported within 5 seconds, and a restart no longer reports a kept disk as deleted.
Forks start on another server when the source's server is full
POST /v1/sandboxes/{id}:fork now returns 503 no_capacity only when no server in the region has room for the copies. When the source's server is full, each copy starts on another server in the region, and the snapshot is copied there first, including large snapshots. The fork's memory limit (a quarter of a server's free memory per fork) now applies to each server the copies can start on, not to the source's server alone.
A sandbox that stops responding is reported within 5 seconds, and a restart no longer reports a kept disk as deleted
A running sandbox that stops responding now returns unreachable, with since and reason (agent_not_answering, disk_stalled or host_quarantined), from GET /v1/sandboxes/{id}, and the new events sandbox.unreachable and sandbox.reachable are sent to webhooks. Previously such a sandbox returned running with no indication. When the sandbox's server cannot finish writing to its disk, a new command now returns sandbox_unreachable (503, retryable) after 5 seconds, with details.reason set to disk_stalled. Previously the request waited about 30 seconds and returned guest_busy (429). The request runs nothing, and commands already running continue. POST /v1/sandboxes/{id}:restart on a running sandbox whose server has not confirmed the reboot's stop now returns sandbox_unreachable (503, retryable) and keeps the disk. Previously it returned not_resumable (409) with diskKept: false. A retry with the same Idempotency-Key waits for the stop, then starts the sandbox from its disk. A command sent to a stopping sandbox now returns sandbox_stopped with "is stopping" instead of "is stopped (ended earlier)". When the server could not pause a sandbox to free disk space, the sandbox keeps running instead of refusing every call. See troubleshooting.