Persistent storage survives the sandbox that created it
Vercel moved Sandbox Drives into public beta on 22 September for Hobby, Pro and Enterprise accounts. A Drive is persistent storage mounted as a directory inside a Vercel Sandbox, and it is independent of the lifetime of that sandbox. Files written to the mount remain after the sandbox stops and the same Drive can be attached to a later sandbox instance.
Vercel positions the primitive around workloads that otherwise repeatedly reconstruct local state, including an agent workspace or on-disk memory, dependency trees, datasets and models. The storage appears through the sandbox filesystem, so applications can use ordinary file operations while the Drive lifecycle is managed separately from the execution environment.
Concurrency follows a single-writer, snapshot-reader model
A Drive can have only one read-write mount at a time. After data has been written, multiple sandboxes can read it concurrently by mounting point-in-time read-only snapshots. Each snapshot reflects the Drive when it was mounted, so writes made later are absent until a new snapshot is created.
That makes Drives useful for fan-out jobs that consume a shared prepared state, but they are not a concurrently writable shared filesystem for several agents. A parallel workflow that needs several writers must coordinate through another layer or serialise Drive writes, while snapshot readers trade freshness for isolation from subsequent changes.
Capacity, region and pricing are explicit constraints
Each sandbox can mount up to four Drives. Vercel sets the default maximum Drive size at 1 TiB, except on Hobby where the default is 1 GiB, and lets customers configure Drives up to 16 TiB before requesting a higher limit. A Drive remains in the region where it was created, sandboxes mounting it must run in that region, and those sandboxes cannot use failover regions.
Pricing is usage based across storage, reads and writes and varies by region. Vercel lists the `iad1` rates at $0.05 per GB-month for storage, $0.0015 per GB read and $0.004 per GB written. Hobby includes 15 GB of Drive storage and 30 GB each of reads and writes per month. Those figures should be treated as regional product pricing rather than a universal rate for every Vercel location.
The beta gives agents durable state with a narrower failure model
For coding and research agents, the practical change is that an execution sandbox no longer has to be the unit of persistence. A repository checkout, dependency cache or generated artefact set can outlive one run and be remounted later, reducing repeated setup and making on-disk memory possible without keeping a sandbox continuously alive.
The public beta still has clear boundaries: the Drive is region-bound, only one writer is permitted and read snapshots do not follow later mutations. Vercel's documentation establishes the storage semantics, limits and pricing, but production performance, consistency under agent-heavy workloads and the operational value of long-lived workspaces still need workload-specific testing. Vercel's release and current documentation establish those shipped details.