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Head to head · Sandbox persist · October 2026 research run

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.

Agent 37 CloudAgent 37 Inc. · HTTP API D46.1/100#514 of 578 Microsoft Execution ContainersMicrosoft · SDK + MCP BB76.3/100#33 of 578

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

CategoryWeight this runAgent 37 CloudMicrosoft Execution ContainersEdge
Reliability16%202781Microsoft Execution Containers +54
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.25781Microsoft Execution Containers +24
Agent ergonomics13%16.26074Microsoft Execution Containers +14
Security & auth14%17.54969Microsoft Execution Containers +20
Payments & pricing10%12.52060Microsoft Execution Containers +40
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.86592Microsoft Execution Containers +27
Transparency & trust7%8.85683Microsoft Execution Containers +27
Negative events≤1500
Total46.1 · D76.3 · BB

Facts side by side

FactAgent 37 CloudMicrosoft Execution Containers
KindHTTP APISDK + MCP
VendorAgent 37 Inc.Microsoft
Hosted endpointhttps://api.agent37.com/v1no (local only)
TransportsHTTP
AuthAPI keyNone
PricingPay per useFree
x402nono
LicenceProprietary 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-2.0MIT
Read-only variant documentednoyes
llms.txtyesno
Last release2026-10-052026-10-06
Terms last updated2026-08-04no document linked
Privacy policy last updated2026-09-01couldn't be read
Customer content may train modelsnot found in the text
Terms restrict automated accessnot found in the text
Terms restrict benchmarkingnot found in the text
Terms or service can change without noticenot found in the text
Arbitration or class-action waivernot found in the text
Popularity74 npm/wk1.5k 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).

Other comparisons with Agent 37 Cloud or Microsoft Execution Containers

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