What changed
On 8 October, Vercel changed Sandbox.create() to resolve after snapshot restoration completes. Startup failures now appear during creation, instead of during the first command or file operation.
Vercel says the change is automatic and requires no SDK upgrade. Restoration time moves into creation; the total time through the first operation is unchanged.
Our perspective
Agent builders should distinguish environment startup from execution. Otherwise a startup failure can look like a failed code-generation step and trigger the wrong recovery action.
Review timeout boundaries and lifecycle telemetry before comparing old and new latency charts. A longer creation step alone does not establish a regression. Track time to the first completed operation as well as each stage.
Go to the source
Primary reporting behind this brief. Our perspective is editorial analysis.