# Deno Sandbox vs Microsoft Execution Containers

> Microsoft Execution Containers scores 76.3 (BB) on agent readiness against Deno Sandbox's 50.3 (D), and leads in every scored category. Both do sandbox code. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/deno-sandbox-vs-microsoft-execution-containers
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- Updated: 2026-10-09

Microsoft Execution Containers scores 76.3 (BB) on agent readiness against Deno Sandbox's 50.3 (D), and leads in every scored category. Both do sandbox code.

- Deno Sandbox: grade D, 50.3/100, rank #689 of 842. Markdown https://www.anchorterminal.com/tools/deno-sandbox.md · JSON https://www.anchorterminal.com/api/v1/tools/deno-sandbox.json
- Microsoft Execution Containers: grade BB, 76.3/100, rank #35 of 842. Markdown https://www.anchorterminal.com/tools/microsoft-execution-containers.md · JSON https://www.anchorterminal.com/api/v1/tools/microsoft-execution-containers.json

## Which one, for what

### Deno Sandbox (D)

Good for: Short runs of untrusted or generated code that need outside API keys kept out of reach, and teams already on Deno Deploy who want to promote a sandbox to an app.

Watch for: Beta since 3 February 2026. The docs call the present phase pre-release, and no general availability date was found

### Microsoft Execution Containers (BB)

Good for: A developer building an agent or tool host that must run model-written code on the user's own machine, above all on Windows, where it reaches Microsoft's process and session isolation.

Ahead on:
- Reliability, 81 against 48
- Schema & documentation, 81 against 66
- Agent ergonomics, 74 against 60
- Security & auth, 69 against 61
- Payments & pricing, 60 against 20
- Maintenance & community, 92 against 45
- Transparency & trust, 83 against 58

Also in its favour:
- Agent-ready, a grade of BB or better
- No key needed to call it
- Free to start without a card
- Open source

Watch for: 1.0.0 shipped on 6 October 2026, and the Node changelog still lists the V1 changes under Unreleased


## Score by category

| Category | Weight | Deno Sandbox | Microsoft Execution Containers | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 48 | 81 | Microsoft Execution Containers +33 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 66 | 81 | Microsoft Execution Containers +15 |
| Agent ergonomics | 13% (16.2 this run) | 60 | 74 | Microsoft Execution Containers +14 |
| Security & auth | 14% (17.5 this run) | 61 | 69 | Microsoft Execution Containers +8 |
| Payments & pricing | 10% (12.5 this run) | 20 | 60 | Microsoft Execution Containers +40 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 45 | 92 | Microsoft Execution Containers +47 |
| Transparency & trust | 7% (8.8 this run) | 58 | 83 | Microsoft Execution Containers +25 |
| Negative events | ≤15 | -2 | 0 | |
| **Total** | | **50.3 · D** | **76.3 · BB** | |

## Facts side by side

| Fact | Deno Sandbox | Microsoft Execution Containers |
| --- | --- | --- |
| Kind | HTTP API | SDK + MCP |
| Vendor | Deno Land Inc. | Microsoft |
| Hosted endpoint | no (local only) | no (local only) |
| Transports | HTTP |  |
| Auth | API key | None |
| Pricing | Paid | Free |
| x402 | no | no |
| Licence | Proprietary service under the Deno Deploy terms and conditions. The `@deno/sandbox` and `deno-sandbox` SDKs are MIT | MIT |
| Read-only variant documented | yes | yes |
| llms.txt | yes | no |
| Last release | 2026-07-22 | 2026-10-06 |
| Terms last updated | 2026-09-30 | no document linked |
| Privacy policy last updated | 2026-09-30 | couldn't be read |
| Customer content may train models | not found in the text |  |
| Terms restrict automated access | not found in the text |  |
| Terms restrict benchmarking | yes |  |
| Terms or service can change without notice | yes |  |
| Arbitration or class-action waiver | yes |  |
| Popularity | 6 stars, 2k npm/wk, 32k PyPI/wk | 1.5k stars, 472k npm/wk |

## Verdicts

**Deno Sandbox.** Secrets stay outside the microVM and are substituted only on outbound requests to approved hosts, and an allowlist limits egress. The service is still in beta, sandboxes need the $20 Pro plan, lifetime is capped at 30 minutes, and no sandbox operation appears in the published OpenAPI document.

**Microsoft Execution Containers.** MXC puts nine operating-system sandbox backends behind one typed request, with network access denied by default and a JSON Schema for the stable 1.0.0 contract. Version 1.0.0 is two days old as of 8 October 2026. Enforcement varies by backend, and `isolation_session` cannot restrict networking at all.

## Before you call either

### Deno Sandbox

1. Set `DENO_DEPLOY_TOKEN` to an organisation token (prefix `ddo_`) from Settings in console.deno.com. The organisation must be on Pro or above
2. Pass `allowNet` on every `Sandbox.create()`. The Security page says outbound access is unrestricted when it is omitted
3. Pass credentials through `secrets` with a `hosts` list, not `env`, so code in the VM sees only a placeholder
4. The default timeout ends the VM when the client disconnects. Pass a duration such as `"10m"` and reconnect with `Sandbox.connect({ id })`, up to 30 minutes
5. Create volumes in `ord` and start the sandbox in `ord`. A volume mounts only in its own region
6. `exposeHttp` URLs are public with no authentication. Treat the random subdomain as a secret

### Microsoft Execution Containers

1. Import from `@microsoft/mxc-sdk/v1`. The package root exports nothing.
2. Call `getPlatformSupport()` first and stop if `isSupported` is false. `getAvailableBackends()` is advisory and launch-time validation still applies.
3. Set `network.egress.default` to `allow` only when the task needs it. Omitted network policy resolves to deny in every direction.
4. Never pass `--audit` to an executor for untrusted code. It turns off all sandbox security for the workload.
5. Read `ExecutionResult.warnings` after each run. Security warnings arrive there and are not written to stdout or stderr.

## Questions

### Which is better for AI agents, Deno Sandbox or Microsoft Execution Containers?

Microsoft Execution Containers scores 76.3 (BB) on agent readiness against Deno Sandbox's 50.3 (D), and leads in every scored category.

### Can an agent call Deno Sandbox and Microsoft Execution Containers without installing anything?

No hosted endpoint is listed for Deno Sandbox. No hosted endpoint is listed for Microsoft Execution Containers.

### Are Deno Sandbox and Microsoft Execution Containers open source?

No open-source release is listed for Deno Sandbox. Microsoft Execution Containers is open source (MIT).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/deno-sandbox-vs-microsoft-execution-containers.json, and with the fewest tokens: https://www.anchorterminal.com/compare/deno-sandbox-vs-microsoft-execution-containers.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "deno-sandbox", "b": "microsoft-execution-containers"}`. From a terminal: `anchor compare deno-sandbox microsoft-execution-containers`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/deno-sandbox.json and https://www.anchorterminal.com/api/v1/tools/microsoft-execution-containers.json

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