Cloudflare Sandboxes
CloudflareCloudflare offers two paths for running agent-generated code on its own network. Dynamic Workers lets a Worker load fresh code at runtime into a separate V8 isolate, starting in milliseconds with network access blocked or intercepted per load; the Sandbox SDK backs the same idea with containers on Workers and Durable Objects, for arbitrary commands, files, background processes and exposed services. Both are reached only through Cloudflare's platform.
Scored as one product per the registry name, though the two paths differ sharply in performance and in what they can run: the isolate path is JavaScript and TypeScript, the container path is general. Verified 2026-08-13 via Cloudflare's "Sandboxing AI agents, 100x faster" post and the cloudflare/sandbox-sdk repository.
Openness
1 high confidence- license
- Proprietary
- source
- closed
- service
- proprietary Cloudflare edge (Workers/Durable Objects/Dynamic Worker Loader - no self-host of the isolate/container plane)
- open-part
- Sandbox SDK only (@cloudflare/sandbox Apache-2.0, cloudflare/sandbox-sdk on GitHub)
- pricing
- Workers paid plan, Dynamic Workers $0.002/unique-worker/day
Closed managed service. The Sandbox SDK is Apache-2.0, but execution requires Cloudflare’s proprietary managed edge network, with no way to self-host the isolate or container plane; an open client SDK over a closed runtime is not open core. One classification wrinkle is worth recording: GitHub reports cloudflare/sandbox-sdk as NOASSERTION because the root LICENSE file is a one-line pointer to packages/sandbox/LICENSE, and that file is the verbatim Apache License 2.0 - the SDK is Apache-2.0 as recorded, and the classifier is simply defeated by the redirect.
- https://github.com/cloudflare/sandbox-sdk recorded 2026-06-04
Apache-2.0 SDK; runs on Cloudflare Containers/Workers/Durable Objects (managed edge)
- https://blog.cloudflare.com/dynamic-workers/ recorded 2026-06-04
Dynamic Worker Loader open beta, isolate sandboxing, post-beta $0.002/worker/day pricing
- https://blog.cloudflare.com/dynamic-workers/ recorded 2026-08-13
Dynamic Worker Loader is an API by which a Cloudflare Worker instantiates another Worker in its own sandbox, running on Cloudflare's platform; open beta to all paid Workers users; priced at $0.002 per unique Worker loaded per day on top of normal Workers CPU and invocation charges. No self-hosted deployment of the isolate or container plane is offered.
- https://api.github.com/repos/cloudflare/sandbox-sdk recorded 2026-08-13
Repository public and unarchived, described as "Run sandboxed code environments on Cloudflare's edge network"; license reported as NOASSERTION because the root LICENSE is a pointer file.
- https://raw.githubusercontent.com/cloudflare/sandbox-sdk/main/packages/sandbox/LICENSE recorded 2026-08-13
The verbatim Apache License 2.0 body, governing the published SDK package that the root LICENSE pointer names.
Adoption
4 medium confidenceThe npm downloads API reports 1,136,848 downloads of @cloudflare/sandbox over the window 2026-07-11 to 2026-08-09, past the 1M floor, which bands at level 4 / 1M-10M. The package is the product’s own - registry metadata points at github.com/cloudflare/sandbox-sdk, the same repository the openness axis reads. The npm figure can be fetched again by hand but no automated feed reads it, so it is a measured number rather than a computed one. Dynamic Workers are in open beta to all paid Workers users, with a named customer (Zite) reporting "millions of execution requests daily" - execution-request volume, which is per-customer rather than distinct-user adoption. Confidence stays medium: the margin over the floor is modest and package pulls carry the usual CI and mirror inflation.
- https://api.npmjs.org/downloads/point/last-month/@cloudflare/sandbox recorded 2026-06-04
~533,043 downloads May 4-Jun 2 2026
- https://api.npmjs.org/downloads/point/last-month/@cloudflare%2Fsandbox recorded 2026-08-14
1,136,848 downloads of package @cloudflare/sandbox over the window start 2026-07-11 to end 2026-08-09. The scoped name is URL-encoded because the npm point endpoint requires it.
- https://registry.npmjs.org/@cloudflare%2Fsandbox recorded 2026-08-14
Registry metadata for the package - repository git+https://github.com/cloudflare/sandbox-sdk.git, homepage github.com/cloudflare/sandbox-sdk#readme, described as "A sandboxed environment for running commands", latest 0.12.5. Confirms the package is the product's own SDK rather than a same-name match.
- https://blog.cloudflare.com/dynamic-workers/ recorded 2026-06-04
open beta to all paid Workers users; Zite millions of execution requests/day
Capability
4 medium confidenceA distinctive isolate-based approach gives best-in-class cold-start and density on the JS/TS isolate path, plus a container path for arbitrary code; held at 4 because isolate sandboxing is JS/TS-centric (narrower than any-image microVMs), Dynamic Workers is still open beta, and the scale evidence is per-customer rather than category-leading. The isolate path and the container path are scored together, as one product. The Dynamic Workers post claims millisecond-scale isolate start, roughly 100x the density of containers and no limit on global concurrent sandboxes or creation rate, and the SDK repository exposes the container-backed path for arbitrary commands, files, background processes and exposed services. Independent ComputeSDK TTI benchmarks measure that container-backed path - the one that runs arbitrary code - at a 4.42s median cold-start, 21st of 24 sandbox providers, where an earlier run had it at ~1.76s and 18th of 19; the sub-millisecond figures apply to the JS/TS Dynamic Workers path, not to the arbitrary-code sandbox the benchmark exercises. On measured full-sandbox latency alone this would be a 3, and it is held at 4 on the strength of the dual isolate-plus-container isolation model, but the measured gap is now wide enough that the hold is the weakest part of this score.
- https://blog.cloudflare.com/dynamic-workers/ recorded 2026-06-04
V8 isolate sandboxing, ~ms start, 100x faster/100x more memory-efficient than containers
- https://github.com/cloudflare/sandbox-sdk recorded 2026-06-04
container-backed sandbox: run commands, manage files, background processes, expose services
- https://www.computesdk.com/benchmarks/sandboxes/ recorded 2026-07-09
ComputeSDK TTI leaderboard (independent, 100 iters/day, 2026-07-09 run): container-backed sandbox median time-to-interactive ~1760ms sequential / ~4290ms burst @100 concurrent; 18th of 19 providers
- https://blog.cloudflare.com/dynamic-workers/ recorded 2026-08-13
V8 isolate sandboxing with ms-scale start and ~100x the memory efficiency of containers; no limit on global concurrent sandboxes or creation rate; network access blockable or interceptable per loaded Worker.
- https://api.github.com/repos/cloudflare/sandbox-sdk recorded 2026-08-13
Repository active and unarchived, described as "Run sandboxed code environments on Cloudflare's edge network" - the container-backed path for arbitrary code.
- https://www.computesdk.com/benchmarks/sandboxes/ recorded 2026-08-13
ComputeSDK TTI leaderboard, run of 2026-08-07 across 24 providers - Cloudflare median 4.42s, P95 5.63s, P99 5.77s, 100% success, composite 50.8; 21st of 24 by median.
Verified 2026-08-13