# Freestyle vs Microsoft Execution Containers

> Microsoft Execution Containers scores 76.3 (BB) on agent readiness against Freestyle's 58.5 (C), and leads in 6 of 7 scored categories. Freestyle leads on schema & documentation. Both do sandbox code. Category scores, facts, verdicts and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/freestyle-vs-microsoft-execution-containers
- Markdown: https://www.anchorterminal.com/compare/freestyle-vs-microsoft-execution-containers.md (~2,700 tokens)
- Slim: https://www.anchorterminal.com/compare/freestyle-vs-microsoft-execution-containers.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/freestyle-vs-microsoft-execution-containers.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-09

Microsoft Execution Containers scores 76.3 (BB) on agent readiness against Freestyle's 58.5 (C), and leads in 6 of 7 scored categories. Freestyle leads on schema & documentation. Both do sandbox code.

- Freestyle: grade C, 58.5/100, rank #520 of 842. Markdown https://www.anchorterminal.com/tools/freestyle.md · JSON https://www.anchorterminal.com/api/v1/tools/freestyle.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

### Freestyle (C)

Good for: Suited to long-running agent work that needs a full Linux VM, memory-preserving pause, snapshots to branch from and private networking.

Ahead on:
- Schema & documentation, 86 against 81

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

Watch for: No terms of service or service agreement found on the site, and the privacy policy covers the website only

### 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 43
- Agent ergonomics, 74 against 69
- Security & auth, 69 against 53
- Payments & pricing, 60 against 45
- Maintenance & community, 92 against 71
- Transparency & trust, 83 against 41

Also in its favour:
- Agent-ready, a grade of BB or better
- No key needed to call it
- 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 | Freestyle | Microsoft Execution Containers | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 43 | 81 | Microsoft Execution Containers +38 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 86 | 81 | Freestyle +5 |
| Agent ergonomics | 13% (16.2 this run) | 69 | 74 | Microsoft Execution Containers +5 |
| Security & auth | 14% (17.5 this run) | 53 | 69 | Microsoft Execution Containers +16 |
| Payments & pricing | 10% (12.5 this run) | 45 | 60 | Microsoft Execution Containers +15 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 71 | 92 | Microsoft Execution Containers +21 |
| Transparency & trust | 7% (8.8 this run) | 41 | 83 | Microsoft Execution Containers +42 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **58.5 · C** | **76.3 · BB** | |

## Facts side by side

| Fact | Freestyle | Microsoft Execution Containers |
| --- | --- | --- |
| Kind | HTTP API | SDK + MCP |
| Vendor | Freestyle Cloud Inc. | Microsoft |
| Hosted endpoint | `https://api.freestyle.sh/v5` | no (local only) |
| Transports | HTTP |  |
| Auth | API key | None |
| Pricing | Freemium | Free |
| x402 | no | no |
| Licence | Proprietary service with no published terms of service found. The `freestyle` SDK and CLI package on npm is MIT | MIT |
| Read-only variant documented | no | yes |
| llms.txt | yes | no |
| Last release | 2026-09-27 | 2026-10-06 |
| Terms last updated | no document linked | no document linked |
| Privacy policy last updated | no document linked | couldn'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 |  |  |
| Popularity | 72k npm/wk | 1.5k stars, 472k npm/wk |

## Verdicts

**Freestyle.** A public OpenAPI 3.1 file describes 88 operations with a stable error code on every failure, and per-VM identity tokens keep the team API key away from end users. No terms of service, product privacy policy, request rate limit or incident history was found, and the only SDK is TypeScript.

**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

### Freestyle

1. Send a `firewall` object on every `POST /v5/vms`. It is required, and a VM with no rules has no outbound internet
2. Ask the owner to run `freestyle login` in a browser once, then mint a key with `freestyle tokens create --output json`
3. Do not retry an exec that answers 409 `VM_NON_RESPONSIVE`. The command may already have run
4. Keep `exec-await` under its 300,000 ms cap and use a PTY session or `x-freestyle-background-after-secs` for longer work
5. Call the `/v5` paths. The unversioned duplicates in the OpenAPI file are marked deprecated

### 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, Freestyle or Microsoft Execution Containers?

Microsoft Execution Containers scores 76.3 (BB) on agent readiness against Freestyle's 58.5 (C), and leads in 6 of 7 scored categories. Freestyle leads on schema & documentation.

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

Freestyle has a hosted endpoint at https://api.freestyle.sh/v5. No hosted endpoint is listed for Microsoft Execution Containers.

### Are Freestyle and Microsoft Execution Containers open source?

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


## For agents

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

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