# Agent 37 Cloud vs Microsoft Execution Containers

> Microsoft Execution Containers scores 76.3 (BB) on agent readiness against Agent 37 Cloud's 46.1 (D), and leads in every scored category. Both do sandbox persist. Category scores, facts, verdicts and agent notes side by side.

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- Updated: 2026-10-08

Microsoft Execution Containers scores 76.3 (BB) on agent readiness against Agent 37 Cloud's 46.1 (D), and leads in every scored category. Both do sandbox persist.

- Agent 37 Cloud: grade D, 46.1/100, rank #564 of 629. Markdown https://www.anchorterminal.com/tools/agent37.md · JSON https://www.anchorterminal.com/api/v1/tools/agent37.json
- Microsoft Execution Containers: grade BB, 76.3/100, rank #34 of 629. 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

### Agent 37 Cloud (D)

Good for: A product that gives each end user a long-lived agent machine that is idle most of the day and needs a harness preinstalled.

Also in its favour:
- A hosted endpoint, with nothing to install

Watch for: No status page was found. status.agent37.com returns 404, and the terms promise no uptime level

### 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 27
- Schema & documentation, 81 against 57
- Agent ergonomics, 74 against 60
- Security & auth, 69 against 49
- Payments & pricing, 60 against 20
- Maintenance & community, 92 against 65
- Transparency & trust, 83 against 56

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 | Agent 37 Cloud | Microsoft Execution Containers | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 27 | 81 | Microsoft Execution Containers +54 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 57 | 81 | Microsoft Execution Containers +24 |
| Agent ergonomics | 13% (16.2 this run) | 60 | 74 | Microsoft Execution Containers +14 |
| Security & auth | 14% (17.5 this run) | 49 | 69 | Microsoft Execution Containers +20 |
| 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) | 65 | 92 | Microsoft Execution Containers +27 |
| Transparency & trust | 7% (8.8 this run) | 56 | 83 | Microsoft Execution Containers +27 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **46.1 · D** | **76.3 · BB** | |

## Facts side by side

| Fact | Agent 37 Cloud | Microsoft Execution Containers |
| --- | --- | --- |
| Kind | HTTP API | SDK + MCP |
| Vendor | Agent 37 Inc. | Microsoft |
| Hosted endpoint | `https://api.agent37.com/v1` | no (local only) |
| Transports | HTTP |  |
| Auth | API key | None |
| Pricing | Pay per use | Free |
| x402 | no | no |
| Licence | Proprietary service under Agent 37's terms of service. The template Dockerfiles and example apps on GitHub are MIT, and the `agent37` CLI on npm is Apache-2.0 | MIT |
| Read-only variant documented | no | yes |
| llms.txt | yes | no |
| Last release | 2026-10-05 | 2026-10-06 |
| Terms last updated | 2026-08-04 | no document linked |
| Privacy policy last updated | 2026-09-01 | 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 | not found in the text |  |
| Terms or service can change without notice | not found in the text |  |
| Arbitration or class-action waiver | not found in the text |  |
| Popularity | 74 npm/wk | 1.5k stars, 472k npm/wk |

## Verdicts

**Agent 37 Cloud.** Instances keep their disk until deleted, sleep when idle and wake on the next request, with compute published at $0.80 a vCPU-month and stable error codes on both APIs. The product launched on 29 September 2026. No status page, OpenAPI file, SDK library or published rate limits were found, and the starter credit needs a card.

**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

### Agent 37 Cloud

1. Send the key as `Authorization: Bearer` to api.agent37.com and as `X-Agent37-Key` to the instance URL. The Bearer form on instance URLs is deprecated
2. Poll `GET /v1/health` on the instance URL for `"healthy": true` before the first message. `status: running` only means the machine is up
3. Check whether `error` is a string before reading `error.code`. Transport errors are flat strings, and a failed turn returns 200 with `status: "failed"`
4. Don't blindly retry an exec that timed out after 13 minutes. The command keeps running, so a retry starts a second copy
5. Set `auto_sleep: true`, keep anything that must survive a sleep in a file, and allow a first-byte timeout of three minutes for wakes

### 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, Agent 37 Cloud or Microsoft Execution Containers?

Microsoft Execution Containers scores 76.3 (BB) on agent readiness against Agent 37 Cloud's 46.1 (D), and leads in every scored category.

### Can an agent call Agent 37 Cloud and Microsoft Execution Containers without installing anything?

Agent 37 Cloud has a hosted endpoint at https://api.agent37.com/v1. No hosted endpoint is listed for Microsoft Execution Containers.

### Are Agent 37 Cloud and Microsoft Execution Containers open source?

No open-source release is listed for Agent 37 Cloud. Microsoft Execution Containers is open source (MIT).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/agent37-vs-microsoft-execution-containers.json, and with the fewest tokens: https://www.anchorterminal.com/compare/agent37-vs-microsoft-execution-containers.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "agent37", "b": "microsoft-execution-containers"}`. From a terminal: `anchor compare agent37 microsoft-execution-containers`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/agent37.json and https://www.anchorterminal.com/api/v1/tools/microsoft-execution-containers.json

## Other comparisons with Agent 37 Cloud or Microsoft Execution Containers

- [Blaxel Sandboxes vs Microsoft Execution Containers](https://www.anchorterminal.com/compare/blaxel-sandboxes-vs-microsoft-execution-containers.md)
- [Cloudflare Sandbox SDK vs Microsoft Execution Containers](https://www.anchorterminal.com/compare/cloudflare-sandbox-sdk-vs-microsoft-execution-containers.md)
- [Daytona vs Microsoft Execution Containers](https://www.anchorterminal.com/compare/daytona-vs-microsoft-execution-containers.md)
- [E2B vs Microsoft Execution Containers](https://www.anchorterminal.com/compare/e2b-vs-microsoft-execution-containers.md)
- [Microsoft Execution Containers vs Modal Sandboxes](https://www.anchorterminal.com/compare/microsoft-execution-containers-vs-modal-sandboxes.md)
- [Microsoft Execution Containers vs Morph Cloud](https://www.anchorterminal.com/compare/microsoft-execution-containers-vs-morph-cloud.md)
- [Microsoft Execution Containers vs Runloop Devboxes](https://www.anchorterminal.com/compare/microsoft-execution-containers-vs-runloop.md)
- [Microsoft Execution Containers vs Vercel Sandbox](https://www.anchorterminal.com/compare/microsoft-execution-containers-vs-vercel-sandbox.md)
- [Agent 37 Cloud vs Blaxel Sandboxes](https://www.anchorterminal.com/compare/agent37-vs-blaxel-sandboxes.md)
- [Agent 37 Cloud vs Cloudflare Sandbox SDK](https://www.anchorterminal.com/compare/agent37-vs-cloudflare-sandbox-sdk.md)
- [Agent 37 Cloud vs Daytona](https://www.anchorterminal.com/compare/agent37-vs-daytona.md)
- [Agent 37 Cloud vs E2B](https://www.anchorterminal.com/compare/agent37-vs-e2b.md)
- [Agent 37 Cloud vs Modal Sandboxes](https://www.anchorterminal.com/compare/agent37-vs-modal-sandboxes.md)
- [Agent 37 Cloud vs Morph Cloud](https://www.anchorterminal.com/compare/agent37-vs-morph-cloud.md)
- [Agent 37 Cloud vs Runloop Devboxes](https://www.anchorterminal.com/compare/agent37-vs-runloop.md)
- [Agent 37 Cloud vs Vercel Sandbox](https://www.anchorterminal.com/compare/agent37-vs-vercel-sandbox.md)