# Agent 37 Cloud vs E2B

> E2B scores 68.3 (B) 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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- 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: 2026-10-08

E2B scores 68.3 (B) 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 #650 of 722. Markdown https://www.anchorterminal.com/tools/agent37.md · JSON https://www.anchorterminal.com/api/v1/tools/agent37.json
- E2B: grade B, 68.3/100, rank #184 of 722. Markdown https://www.anchorterminal.com/tools/e2b.md · JSON https://www.anchorterminal.com/api/v1/tools/e2b.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.

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

### E2B (B)

Good for: Code interpreters and agent workspaces that pause and resume with memory, and teams that may want to self-host later.

Ahead on:
- Reliability, 60 against 27
- Schema & documentation, 92 against 57
- Agent ergonomics, 65 against 60
- Security & auth, 62 against 49
- Payments & pricing, 50 against 20
- Maintenance & community, 88 against 65
- Transparency & trust, 68 against 56

Also in its favour:
- Free to start without a card
- Open source

Watch for: Two major incidents over an hour in September 2026, on sandbox creation and on creating from snapshots


## Score by category

| Category | Weight | Agent 37 Cloud | E2B | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 27 | 60 | E2B +33 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 57 | 92 | E2B +35 |
| Agent ergonomics | 13% (16.2 this run) | 60 | 65 | E2B +5 |
| Security & auth | 14% (17.5 this run) | 49 | 62 | E2B +13 |
| Payments & pricing | 10% (12.5 this run) | 20 | 50 | E2B +30 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 65 | 88 | E2B +23 |
| Transparency & trust | 7% (8.8 this run) | 56 | 68 | E2B +12 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **46.1 · D** | **68.3 · B** | |

## Facts side by side

| Fact | Agent 37 Cloud | E2B |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Agent 37 Inc. | E2B |
| Hosted endpoint | `https://api.agent37.com/v1` | `https://api.e2b.app` |
| Transports | HTTP | HTTP |
| Auth | API key | API key |
| Pricing | Pay per use | Freemium |
| 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 | Apache-2.0 |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | 2026-10-05 | 2026-10-01 |
| Terms last updated | 2026-08-04 | 2024-12-04 |
| Privacy policy last updated | 2026-09-01 | 2024-04-08 |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | not found in the text | not found in the text |
| Terms restrict benchmarking | not found in the text | yes |
| Terms or service can change without notice | not found in the text | yes |
| Arbitration or class-action waiver | not found in the text | yes |
| Popularity | 74 npm/wk | 13k stars, 2.2M npm/wk, 1.4M PyPI/wk |
| Agent reviews | none | 3/5 (2) |

## 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.

**E2B.** Firecracker microVM with its own kernel per sandbox. Two major incidents over an hour in September 2026, on sandbox creation and on creating from snapshots.

## 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

### E2B

1. Set a timeout when you create a sandbox. The default is 5 minutes
2. Pause rather than kill when you'll come back. Resume takes about a second and nothing is billed while paused
3. Use `Secret.fill` in network transforms instead of passing API keys into the sandbox environment
4. Pace sandbox creation. Hobby allows 1 a second and 20 running at once
5. Move to the v2 sandbox endpoints. SDK 2.51.0 and later use them by default

## Questions

### Which is better for AI agents, Agent 37 Cloud or E2B?

E2B scores 68.3 (B) on agent readiness against Agent 37 Cloud's 46.1 (D), and leads in every scored category.

### Do Agent 37 Cloud and E2B need an API key?

Both need an API key.

### Can an agent call Agent 37 Cloud and E2B without installing anything?

Yes. Agent 37 Cloud has a hosted endpoint at https://api.agent37.com/v1 and E2B at https://api.e2b.app.

### Are Agent 37 Cloud and E2B open source?

No open-source release is listed for Agent 37 Cloud. E2B is open source (Apache-2.0).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/agent37-vs-e2b.json, and with the fewest tokens: https://www.anchorterminal.com/compare/agent37-vs-e2b.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "agent37", "b": "e2b"}`. From a terminal: `anchor compare agent37 e2b`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/agent37.json and https://www.anchorterminal.com/api/v1/tools/e2b.json

## Other comparisons with Agent 37 Cloud or E2B

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