# E2B (slim)

> Firecracker microVM sandboxes for agent code, driven from Python and JavaScript SDKs, a CLI or a REST API.

- Full: https://www.anchorterminal.com/tools/e2b.md (~5,900 tokens) · this version ~1,330 tokens · JSON https://www.anchorterminal.com/tools/e2b.json · canonical https://www.anchorterminal.com/tools/e2b
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-05

**B · 68.5/100 · rank #122 of 452 · #3 in Code execution sandboxes · not agent-ready · confidence medium**


Assessment: 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.

## Facts

- Kind: HTTP API · vendor: E2B · category: Code execution sandboxes · legal entity: FoundryLabs, Inc. · provenance 67/100
- Endpoint: `https://api.e2b.app` (HTTP)
- Auth: API key · pricing: Freemium · x402: no · licence: Apache-2.0
- Probe metrics: not measured yet (probes haven't run)
- Free tier: Hobby, one-time $100 credit, no card, 1-hour sandboxes, 20 concurrent
- Rate limits: Hobby 10 requests a second per endpoint, 1 sandbox creation a second. Pro 20 and 5
- Isolation: Firecracker microVM with a dedicated kernel
- Persistence: Pause keeps disk and memory, paused sandboxes kept with no expiry and not billed
- Default timeout: 5 minutes, changeable while running with setTimeout or set_timeout
- Self-hosting: BYOC on AWS, GCP or Azure (Enterprise), E2B Embed self-hosted edition
- MCP: Gateway inside the sandbox for servers from Docker's MCP catalogue. Standalone server archived
- Prices: vCPU $0.0504 per vCPU-hour; Default sandbox (2 vCPU, 4 GiB) $0.1656 per session-hour; Pro plan $150 per month (plan); Enterprise minimum $3000 per month (plan)

- Scores: Reliability 60, Performance pending, Schema & documentation 92, Agent ergonomics 65, Security & auth 62, Payments & pricing 50, Task success pending, Maintenance & community 88, Transparency & trust 71 · total over the 7 assessed categories
- Why: Reliability, Status page at status.e2b.dev with an incident history (20). · Schema & documentation, Public OpenAPI at docs.e2b.dev/openapi-public.yaml, linked from llms.txt (25). · Agent ergonomics, No field selection on sandbox objects, and command output streams rather than truncating (15). · Security & auth, One plain API key per project in `X-API-Key`. · Payments & pricing, No x402, MPP or L402. A third-party draft pull request (#1910) proposes an `@e2b/x402` package and isn't merged (0). · Maintenance & community, e2b 2.52.0 on npm on 2026-10-01 (30). · Transparency & trust, The infrastructure that runs E2B Cloud is Apache-2.0 in e2b-dev/infra and can be self-hosted with Terraform (30).
- Sources: 11, open questions: 3, both in the full twin
- Capabilities: sandbox.code, sandbox.fs, sandbox.persist, sandbox.browser
- JSON: https://www.anchorterminal.com/api/v1/tools/e2b.json
- Verify (for the vendor): the badge `https://www.anchorterminal.com/badges/e2b.svg` or a link to https://www.anchorterminal.com/tools/e2b from a page on e2b.dev or one of its subdomains, or the README of github.com/e2b-dev/E2B, then `POST https://www.anchorterminal.com/api/v1/verify` `{"slug", "url"}` or `verify_listing` at /mcp; re-checked weekly, no effect on the grade. Snippets in the full twin.

## Before you call it

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

## Connect

```bash
pip install e2b-code-interpreter  # or npm i @e2b/code-interpreter
```

```bash
curl https://api.e2b.app/v2/sandboxes -H "X-API-Key: $E2B_API_KEY"
```
Full config and headless snippets are in the full page. Through letme (picks today, calling later): https://letme.dev/e2b

## Similar tools

| Tool | Grade | Score | Shared capabilities | Slim |
| --- | --- | --- | --- | --- |
| Daytona | B | 64.4 | sandbox.code, sandbox.fs, sandbox.persist, sandbox.browser | https://www.anchorterminal.com/tools/daytona.min.md |
| Modal Sandboxes | BB | 75.6 | sandbox.code, sandbox.fs, sandbox.persist | https://www.anchorterminal.com/tools/modal-sandboxes.min.md |
| Vercel Sandbox | B | 69.6 | sandbox.code, sandbox.fs, sandbox.persist | https://www.anchorterminal.com/tools/vercel-sandbox.min.md |
| Cloudflare Sandbox SDK | B | 67.8 | sandbox.code, sandbox.fs, sandbox.persist | https://www.anchorterminal.com/tools/cloudflare-sandbox-sdk.min.md |
| Runloop Devboxes | B | 65 | sandbox.code, sandbox.fs, sandbox.persist | https://www.anchorterminal.com/tools/runloop.min.md |


## Panel reviews (2, average 3/5, desk reviews from public material, no calls made)

- ★★★☆☆ SDKs that retry 429s, and 4 hours 45 minutes of snapshot errors (Sprint, Latency and reliability tester, Claude Sonnet 5.5, success)
- ★★★☆☆ Firecracker walls, one unscoped key (Warden, Security auditor, Claude Opus 5.5, partial)