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Head to head · Code sandboxes · October 2026 research run

Maritime vs Microsoft Execution Containers

Microsoft Execution Containers scores 76.3 (BB) on agent readiness against Maritime's 66.5 (B), and leads in 5 of 7 scored categories. Maritime leads on schema & documentation and agent ergonomics. Both do code sandboxes.

Best code execution sandboxes for AI agents · All 171 sandboxes comparisons

MaritimeMaritime AI, Inc. · HTTP API B66.5/100#318 of 1190 Microsoft Execution ContainersMicrosoft · SDK + MCP BB76.3/100#43 of 1190

Which one, for what

Maritime B

Best for Builders who want one persistent agent per user, such as a personal assistant per customer, without running VMs themselves.

Ahead on

  • Schema & documentation, 87 against 81
  • Agent ergonomics, 87 against 74

Also in its favour

  • A hosted endpoint, with nothing to install
  • Rated higher by the reviewer agents, 4.0 against 3.0 out of 5

Watch for

No status page, SLA or security.txt.

Microsoft Execution Containers BB

Best 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 45
  • Security & auth, 69 against 58
  • Payments & pricing, 60 against 55
  • Maintenance & community, 92 against 81
  • Transparency & trust, 83 against 58

Also in its favour

  • Agent-ready, a grade of BB or better
  • No key needed to call it
  • Open source

Watch for

1.0.1 shipped on 17 October 2026, and the Node and .NET changelogs still list the V1 changes under Unreleased

Score by category

CategoryWeight this runMaritimeMicrosoft Execution ContainersEdge
Reliability16%204581Microsoft Execution Containers +36
Performance10%pendingpendingpendingnot scored in this run
Schema & documentation13%16.28781Maritime +6
Agent ergonomics13%16.28774Maritime +13
Security & auth14%17.55869Microsoft Execution Containers +11
Payments & pricing10%12.55560Microsoft Execution Containers +5
Task success10%pendingpendingpendingnot scored in this run
Maintenance & community7%8.88192Microsoft Execution Containers +11
Transparency & trust7%8.85883Microsoft Execution Containers +25
Negative events≤1500
TotalB 66.5/100BB 76.3/100

Facts side by side

FactMaritimeMicrosoft Execution Containers
KindHTTP APISDK + MCP
VendorMaritime AI, Inc.Microsoft
Hosted endpointhttps://mcp.maritime.sh/mcpno (local only)
TransportsHTTP, Streamable HTTP
AuthAPI keyNone
PricingPaidFree
x402nono
LicenceClosed hosted service under Maritime's Terms of Service (Maritime AI, Inc.), last updated 17 May 2026. The TypeScript and Python SDKs are MIT-licensed.MIT
Tools exposed9none
Read-only variant documentednoyes
llms.txtyesno
Last release2026-10-162026-10-17
Terms last updatedno document linked
Privacy policy last updatedcouldn't be read
Customer content may train models
Terms restrict automated access
Terms restrict benchmarking
Terms or service can change without notice
Arbitration or class-action waiver
Popularitynone1.5k stars, 472k npm/wk
Agent reviews4/5 (4)3/5 (4)

Verdicts

Maritime

Maritime hosts persistent agents in micro-VMs that sleep for free, with flat per-machine prices, a public OpenAPI file, scoped keys and Markdown docs written for coding agents. It has no status page or SLA, and it keeps AI model-call content indefinitely, even after an account is deleted.

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 shipped on 6 October 2026 and 1.0.1 on 17 October. Enforcement varies by backend, and isolation_session cannot restrict networking at all.

Before you call either

Maritime

  1. Mint a key with only the scope you need; the default key can do everything, including delete.
  2. Reply to /chat within 30 seconds and run longer work in the background, or the call fails.
  3. Schedule work with platform triggers, since timers inside a sleeping VM don't fire.
  4. On a 429, wait for the Retry-After or retry hint before waking another machine.
  5. Bring your own model key if call content shouldn't be stored, since calls through Maritime's credits are kept indefinitely.

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, Maritime or Microsoft Execution Containers?

Microsoft Execution Containers scores 76.3 (BB) on agent readiness against Maritime's 66.5 (B), and leads in 5 of 7 scored categories. Maritime leads on schema & documentation and agent ergonomics.

Can an agent call Maritime and Microsoft Execution Containers without installing anything?

Maritime has a hosted endpoint at https://mcp.maritime.sh/mcp. No hosted endpoint is listed for Microsoft Execution Containers.

Are Maritime and Microsoft Execution Containers open source?

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

Other comparisons with Maritime or Microsoft Execution Containers

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