# Celesto (formerly SmolVM) vs Freestyle

> Celesto scores 68 (B) to Freestyle's 59.6 (C) for code sandboxes. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/celesto-vs-freestyle
- Markdown: https://www.anchorterminal.com/compare/celesto-vs-freestyle.md (~4,500 tokens)
- Site index for agents: https://www.anchorterminal.com/llms.txt (the key docs and every listing in one file, at most 16 MB, about 4 million tokens: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- MCP: https://www.anchorterminal.com/mcp (the whole catalogue as tools, no key)
- DNS: dig +short TXT <slug>.grade.anchorterminal.com (the grade as a DNS TXT record, for a sandbox with no HTTP where names still resolve; also top., best.<category>. and <a>.vs.<b>. under the zone, and the same under grade.letme.dev)
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)
- Updated: 2026-11-07

Celesto (formerly SmolVM) scores 68 (B) on agent readiness against Freestyle's 59.6 (C), and leads in 4 of 7 scored categories. Both do code sandboxes.

- Celesto (formerly SmolVM): grade B, 68/100, rank #298 of 1486. Markdown https://www.anchorterminal.com/tools/celesto.md · JSON https://www.anchorterminal.com/api/v1/tools/celesto.json
- Freestyle: grade C, 59.6/100, rank #693 of 1486. Markdown https://www.anchorterminal.com/tools/freestyle.md · JSON https://www.anchorterminal.com/api/v1/tools/freestyle.json
- Best code execution sandboxes for AI agents: https://www.anchorterminal.com/best/code-sandboxes/index.md
- All 231 sandboxes comparisons: https://www.anchorterminal.com/compare/code-sandboxes/index.md

## Which one, for what

### Celesto (formerly SmolVM) (B)

Good for: Local microVM sandboxes for agent code, browsers and desktops on Linux and macOS, with a path to a hosted cloud.

Ahead on:
- Reliability, 66 against 47
- Payments & pricing, 60 against 45
- Maintenance & community, 81 against 71
- Transparency & trust, 70 against 44

Also in its favour:
- No key needed to call it
- Open source

Watch for: Version 0.1.13 and declared pre-1.0 in SECURITY.md, with the TypeScript SDK an alpha installed from a GitHub tarball

### 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.

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


## Why the edge

### Transparency & trust: Celesto (formerly SmolVM) +26

- Celesto (formerly SmolVM) (70): Apache-2.0 in LICENSE and on PyPI (30). The privacy policy of 30 October 2026 links a subprocessor registry and describes the CLI telemetry in the same terms as the docs, but gives no retention periods beyond as long as necessary. Stopped cloud disks are kept 30 days per the pricing page (18 of 30). The changelog marks removals and the breaking rename, and the glossary lists older names still accepted, with no written deprecation policy (10 of 20). Telemetry is disclosed in the README, CLI reference and privacy policy, with three opt-outs, but it is on by default after the notice (16 of 20). Total 74.
- Freestyle (44): The platform is closed. The SDK and CLI are MIT on npm, and no terms of service or service agreement was found on www.freestyle.sh (`/terms`, `/tos` and `/legal` still answer 404 on 4 November), so the terms of use are unclear (8 of 30). The privacy policy, last updated 15 June 2025, covers the website only, and no DPA, retention period or statement on customer VM data was found (3 of 30). The 9 September 2026 changelog deprecates the Git, code execution, web deployment and scheduled trigger APIs, and the OpenAPI file marks every unversioned route deprecated, in both cases without a removal date (6 of 20). The privacy policy names Google Analytics and PostHog for the website. No sub-processor list or data location for VMs was found (3 of 20). 8 + 3 + 6 + 3 = 20.

### Reliability: Celesto (formerly SmolVM) +19

- Celesto (formerly SmolVM) (66): Read with the local-software lines, because the graded surface runs on the owner's machine. Installs from PyPI as `celesto` with Python 3.11 or newer on Linux and macOS stated, plus an install script (20). The repository has pytest, e2e, lint, TypeScript and smoke-test workflows and 38 test packages, but GitHub's API answered with a rate limit, so no run result was read (15 of 25, unchecked). 22 open issues and pull requests against about 188 commits in 90 days. The open bugs include a snapshot restore that can lose a VM's disk if interrupted and a thread-safety issue with five replies (18 of 25). A dated changelog with Security, Fixed, Added and Removed sections, and the rename to Celesto marked as a breaking release, though versions stay below 1.0 (13 of 15). Pre-1.0 per SECURITY.md (0). Total 66.
- Freestyle (47): Graded on the hosted lines. www.freestyle.sh/status is the vendor's own page with three components (Freestyle VMs, API, Dashboard), all operational, last updated 25 October 2026 on 4 November, with no incident list or component history (10 of 20). No readable history (5). Plan limits are published with numbers (10, 40 and 400 concurrent VMs, per-VM and total resource budgets), but no request rate limit for the API was found in the reviewed documentation (5 of 15). The OpenAPI file documents 429 `LIMIT_EXCEEDED` on VM creation and resize and marks which 409s are safe to retry, per the 8 October check (the file wasn't re-read on 4 November), resumable uploads take retryable chunks, and the SDK's terminal sessions reconnect with exponential backoff and jitter without rerunning a command. No Retry-After header or idempotency keys found. That is safe-retry guidance without idempotency keys, 12 in this run, where 8 was given on 8 October (12 of 15). The pricing page lists a 99.99% SLA for Enterprise with no SLA document published (5 of 10). The API is served under `/v5` with no beta label (10). 10 + 5 + 5 + 12 + 5 + 10 = 47.

### Payments & pricing: Celesto (formerly SmolVM) +15

- Celesto (formerly SmolVM) (60): Read with the self-hosted rule, scoring the hosted option for the price lines. No x402, MPP or L402 (0 of 40). Celesto Cloud publishes hourly prices for six sizes without a login (20). A one-time $5 Micro credit needs no card, and the local SDK is free (20). The graded local SDK installs from PyPI and runs with no account, so an agent needs no signup (20). Cloud use needs a browser signup and a card top-up. Total 60.
- Freestyle (45): No x402, MPP or L402 found in the docs, the OpenAPI file or the pricing page (0). Per-unit prices are public, $0.04032 a vCPU-hour, $0.0129 a GiB-hour of memory, $0.000086 a GiB-hour of storage and $0.02 a GB of data transfer (20). The Free plan costs $0 with 200 vCPU-hours and 400 GiB-hours of memory a month and needs no card (20). A person has to sign in through a browser first. After that an agent can mint its own key with `freestyle tokens create --output json`, so 5 of 20 (5). Pricing re-read on 4 November, unchanged. 0 + 20 + 20 + 5 = 45.

### Maintenance & community: Celesto (formerly SmolVM) +10

- Celesto (formerly SmolVM) (81): 0.1.13 on PyPI on 5 November 2026, tagged 6 November (30). 22 PyPI releases in the 90 days to 6 November (20). Most open issues are filed by maintainers. Outside reports such as the thread-safety issue got replies, and several recent ones have none yet; pull-request reply times were not read (15 of 25). The Python SDK is current, the TypeScript SDK is an alpha not published to npm (8 of 15). uv and Cargo lock files, CodeQL and publish workflows, with run results unread (8 of 10). Total 81.
- Freestyle (71): The newest dated change is the 14 October 2026 changelog entry (browser terminals, expiring identity tokens, 24-hour commands, scoped S3 access), 21 days before this check. `freestyle` 0.2.16 was published to npm on 27 September 2026, per the 8 October check (30). 25 npm versions between 13 August and 27 September 2026 per the 8 October check, and changelog entries on 9 September and 14 October, all inside the 90 days from 6 August. npm couldn't be re-read on 4 November (20). Closed service with a public changelog of four entries in 2026 and a Discord server, whose response times we did not check (8 of 15). One current official SDK, TypeScript, with the CLI in the same package (10 of 15). The package has three dependencies and no `repository` field, and no public CI was found, per the 8 October check (3 of 10). 30 + 20 + 8 + 10 + 3 = 71.

## Score by category

| Category | Weight | Celesto (formerly SmolVM) | Freestyle | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 66 | 47 | Celesto (formerly SmolVM) +19 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 85 | 86 | Freestyle +1 |
| Agent ergonomics | 13% (16.2 this run) | 69 | 69 | even |
| Security & auth | 14% (17.5 this run) | 52 | 53 | Freestyle +1 |
| Payments & pricing | 10% (12.5 this run) | 60 | 45 | Celesto (formerly SmolVM) +15 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 81 | 71 | Celesto (formerly SmolVM) +10 |
| Transparency & trust | 7% (8.8 this run) | 70 | 44 | Celesto (formerly SmolVM) +26 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **68 · B** | **59.6 · C** | |

## Facts side by side

| Fact | Celesto (formerly SmolVM) | Freestyle |
| --- | --- | --- |
| Kind | SDK + MCP | HTTP API |
| Vendor | Celesto AI, Inc. | Freestyle Cloud Inc. |
| Hosted endpoint | no (local only) | `https://api.freestyle.sh/v5` |
| Transports |  | HTTP |
| Auth | None | API key |
| Pricing | Freemium | Freemium |
| x402 | no | no |
| Licence | Apache-2.0 | Proprietary service with no published terms of service found. The `freestyle` SDK and CLI package on npm is MIT |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-11-05 | 2026-09-27 |
| Terms last updated | 2026-10-30 | no document linked |
| Privacy policy last updated | 2026-10-30 | no document linked |
| Customer content may train models | not found in the text | not read yet |
| Terms restrict automated access | not found in the text | not read yet |
| Terms restrict benchmarking | not found in the text | not read yet |
| Terms or service can change without notice | not found in the text | not read yet |
| Arbitration or class-action waiver | not found in the text | not read yet |
| Popularity | 1.1k stars, 699 PyPI/wk | 72k npm/wk |

## How the scores have moved

### Celesto (formerly SmolVM)

No score change since it was listed.

### Freestyle

- +0.8 on 4 November 2026: correction
- +0.3 on 27 October 2026: new evidence

## Verdicts

**Celesto (formerly SmolVM).** Celesto runs each agent task in a local Firecracker or QEMU microVM with its own kernel, driven by a CLI with a stable JSON envelope and a Python SDK, free under Apache-2.0. It is pre-1.0, renamed from SmolVM on 19 September 2026, sends usage telemetry after a first-use notice, and leaves outbound networking open unless a mode is set.

**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.

## Before you call either

### Celesto (formerly SmolVM)

1. Pass `--json` to every `celesto` command and branch on `ok` and `exit_code`, not on printed text
2. Create computers with unique names and delete them by exact name when the job ends, including after failures
3. Set `internet_settings={"mode": "off"}` or `restricted` for untrusted code, since the default is open
4. Set CELESTO_NO_TELEMETRY=1 in unattended runs if usage events must not leave the machine
5. Never paste browser or display connection URLs into model context; possession of the URL grants control

### 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 300 seconds on older guest agents. The 14 October changelog lets `vm.exec()` run up to 24 hours on VMs with an updated guest agent
5. Call the `/v5` paths. The unversioned duplicates in the OpenAPI file are marked deprecated

## Questions

### Which is better for AI agents, Celesto (formerly SmolVM) or Freestyle?

Celesto (formerly SmolVM) scores 68 (B) on agent readiness against Freestyle's 59.6 (C), and leads in 4 of 7 scored categories.

### Can an agent call Celesto (formerly SmolVM) and Freestyle without installing anything?

No hosted endpoint is listed for Celesto (formerly SmolVM). Freestyle has a hosted endpoint at https://api.freestyle.sh/v5.

### Are Celesto (formerly SmolVM) and Freestyle open source?

Celesto (formerly SmolVM) is open source (Apache-2.0). No open-source release is listed for Freestyle.


## For agents

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

## Other comparisons with Celesto (formerly SmolVM) or Freestyle

- [Amazon Bedrock AgentCore Code Interpreter vs Celesto (formerly SmolVM)](https://www.anchorterminal.com/compare/agentcore-code-interpreter-vs-celesto.md)
- [Amazon Bedrock AgentCore Code Interpreter vs Freestyle](https://www.anchorterminal.com/compare/agentcore-code-interpreter-vs-freestyle.md)
- [Blaxel Sandboxes vs Celesto (formerly SmolVM)](https://www.anchorterminal.com/compare/blaxel-sandboxes-vs-celesto.md)
- [Blaxel Sandboxes vs Freestyle](https://www.anchorterminal.com/compare/blaxel-sandboxes-vs-freestyle.md)
- [Celesto (formerly SmolVM) vs Cloudflare Sandbox SDK](https://www.anchorterminal.com/compare/celesto-vs-cloudflare-sandbox-sdk.md)
- [Celesto (formerly SmolVM) vs Daytona](https://www.anchorterminal.com/compare/celesto-vs-daytona.md)
- [Celesto (formerly SmolVM) vs DeltaBox Lite](https://www.anchorterminal.com/compare/celesto-vs-deltabox-lite.md)
- [Celesto (formerly SmolVM) vs Deno Sandbox](https://www.anchorterminal.com/compare/celesto-vs-deno-sandbox.md)
- [Celesto (formerly SmolVM) vs E2B](https://www.anchorterminal.com/compare/celesto-vs-e2b.md)
- [Celesto (formerly SmolVM) vs InstaVM](https://www.anchorterminal.com/compare/celesto-vs-instavm.md)
- [Celesto (formerly SmolVM) vs Maritime](https://www.anchorterminal.com/compare/celesto-vs-maritime.md)
- [Celesto (formerly SmolVM) vs Microsoft Execution Containers](https://www.anchorterminal.com/compare/celesto-vs-microsoft-execution-containers.md)
- [Celesto (formerly SmolVM) vs Modal Sandboxes](https://www.anchorterminal.com/compare/celesto-vs-modal-sandboxes.md)
- [Celesto (formerly SmolVM) vs Morph Cloud](https://www.anchorterminal.com/compare/celesto-vs-morph-cloud.md)
- [Celesto (formerly SmolVM) vs Offscreen](https://www.anchorterminal.com/compare/celesto-vs-offscreen.md)
- [Celesto (formerly SmolVM) vs SPACE](https://www.anchorterminal.com/compare/celesto-vs-perplexity-space.md)
- [Celesto (formerly SmolVM) vs Runloop Devboxes](https://www.anchorterminal.com/compare/celesto-vs-runloop.md)
- [Celesto (formerly SmolVM) vs Sandbox0](https://www.anchorterminal.com/compare/celesto-vs-sandbox0.md)
- [Celesto (formerly SmolVM) vs Sprites](https://www.anchorterminal.com/compare/celesto-vs-sprites.md)
- [Celesto (formerly SmolVM) vs Together Code Sandbox](https://www.anchorterminal.com/compare/celesto-vs-together-code-sandbox.md)
- [Celesto (formerly SmolVM) vs Vercel Sandbox](https://www.anchorterminal.com/compare/celesto-vs-vercel-sandbox.md)
- [Cloudflare Sandbox SDK vs Freestyle](https://www.anchorterminal.com/compare/cloudflare-sandbox-sdk-vs-freestyle.md)
- [Daytona vs Freestyle](https://www.anchorterminal.com/compare/daytona-vs-freestyle.md)
- [Deno Sandbox vs Freestyle](https://www.anchorterminal.com/compare/deno-sandbox-vs-freestyle.md)
- [E2B vs Freestyle](https://www.anchorterminal.com/compare/e2b-vs-freestyle.md)
- [Freestyle vs InstaVM](https://www.anchorterminal.com/compare/freestyle-vs-instavm.md)
- [Freestyle vs Maritime](https://www.anchorterminal.com/compare/freestyle-vs-maritime.md)
- [Freestyle vs Microsoft Execution Containers](https://www.anchorterminal.com/compare/freestyle-vs-microsoft-execution-containers.md)
- [Freestyle vs Modal Sandboxes](https://www.anchorterminal.com/compare/freestyle-vs-modal-sandboxes.md)
- [Freestyle vs Morph Cloud](https://www.anchorterminal.com/compare/freestyle-vs-morph-cloud.md)
- [Freestyle vs Offscreen](https://www.anchorterminal.com/compare/freestyle-vs-offscreen.md)
- [Freestyle vs SPACE](https://www.anchorterminal.com/compare/freestyle-vs-perplexity-space.md)
- [Freestyle vs Runloop Devboxes](https://www.anchorterminal.com/compare/freestyle-vs-runloop.md)
- [Freestyle vs Sandbox0](https://www.anchorterminal.com/compare/freestyle-vs-sandbox0.md)
- [Freestyle vs Sprites](https://www.anchorterminal.com/compare/freestyle-vs-sprites.md)
- [Freestyle vs Together Code Sandbox](https://www.anchorterminal.com/compare/freestyle-vs-together-code-sandbox.md)
- [Freestyle vs Vercel Sandbox](https://www.anchorterminal.com/compare/freestyle-vs-vercel-sandbox.md)
- [Agent 37 Cloud vs Celesto (formerly SmolVM)](https://www.anchorterminal.com/compare/agent37-vs-celesto.md)
- [Agent 37 Cloud vs Freestyle](https://www.anchorterminal.com/compare/agent37-vs-freestyle.md)
- [DeltaBox Lite vs Freestyle](https://www.anchorterminal.com/compare/deltabox-lite-vs-freestyle.md)

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Query this catalogue directly over MCP: https://www.anchorterminal.com/mcp (Streamable HTTP, no key). How: https://www.anchorterminal.com/agents/#mcp