# Steel (slim)

> Steel runs cloud browser sessions for AI agents, controlled through a REST API, a CDP WebSocket, SDKs, a CLI and an official MCP server. Its browser runtime, steel-browser, is open source and can be self-hosted.

- Full: https://www.anchorterminal.com/tools/steel.md (~8,900 tokens) · this version ~2,080 tokens · JSON https://www.anchorterminal.com/tools/steel.json · canonical https://www.anchorterminal.com/tools/steel
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-08

**BB · 70.4/100 · rank #129 of 629 · #5 in Browser automation · agent-ready · confidence medium**


Assessment: The hosted API has a public OpenAPI document, per-unit prices, $30 of starting credit and x402 payment for scrape, screenshot and PDF calls. The status page records three API or session-creation incidents of more than an hour in 90 days, and the documented CDP connection puts the API key in the URL.

## Facts

- Kind: HTTP API · vendor: Nen Labs, Inc. · category: Browser automation · legal entity: Nen Labs, Inc. · provenance 75/100
- Endpoint: `https://api.steel.dev` (HTTP, stdio)
- Auth: API key · pricing: Freemium · x402: yes, from $0.01/call · licence: Proprietary cloud service under Steel's terms. steel-browser and the Node and Python SDKs are Apache-2.0. The MCP server and the CLI are MIT
- Probe metrics: not measured yet (probes haven't run)
- Surface graded: Steel Cloud, the hosted API at https://api.steel.dev with CDP at wss://connect.steel.dev. The open-source steel-browser and the MCP server are described but not graded separately
- API: OpenAPI 3.0.3 with 51 paths and 75 operations under /v1. Sessions, Browser Tools (scrape, screenshot, PDF), Files, Profiles, Credentials, Extensions, Captchas, Projects, Secrets, Environments and Computers
- MCP server: Official, MIT, stdio from GitHub with `npx -y github:steel-dev/steel-mcp-server`, Node 20 or later. 16 tools in the `browse` profile, 3 in `scrape`. Latest tagged release v2.0.1 on 24 August 2026, 3.0.0 on main. Not on npm, not in the MCP registry, no hosted endpoint yet
- Free tier: Launch plan, $30 of one-time credit valid 90 days, 10 concurrent sessions, 15 minutes a session, 7-day data retention, up to 3 seats
- Rate limits: 60 requests a minute on Launch and 600 on Scale. Browser Tools 20 requests a minute per organisation. Concurrent sessions 10 on Launch, 100 on Scale, 1,000+ on Enterprise
- Session limits: Default timeout 5 minutes. Maximum 15 minutes on Launch, 1 hour on Scale, up to 24 hours on Enterprise. `inactivityTimeout` releases an idle session early
- Errors: JSON error body with `message`, optional `error`, `linkToDocs` and validation `context`. Browser Tools document 402, 408, 429 and 503, with 503 marked safe to retry. The SDKs retry 408, 409, 429 and 5xx twice with backoff
- Machine payment: x402 version 2 at x402.steel.dev for /v1/scrape, /v1/screenshot and /v1/pdf, $0.01 a call, USDC on Base or Solana
- SDKs and CLI: Node `steel-sdk` 0.18.0 on npm (16 March 2026, with 0.21.0 previews from September) and Python `steel-sdk` 0.19.0 on PyPI (23 June 2026), both generated by Stainless. Rust and Go SDKs per Steel's blog. CLI `@steel-dev/cli` 0.3.1 on npm, with 0.5.0 previews tagged on GitHub
- Self-hosting: steel-browser, Apache-2.0, Docker image, latest tag v0.5.4-beta on 25 August 2026. One concurrent session, bring your own proxies
- Observability: Live session viewer, recordings (can be turned off per session with `recording: false`), session logs, Agent Traces as JSON, and a per-session cost endpoint
- Security: HIPAA-ready BAA and SSO on Scale and Enterprise per the pricing page. Vanta trust centre at trust.steel.dev. No security.txt
- Region: Browsers run in us-east only per the session configuration docs. The privacy notice says servers are in the United States
- Prices: Browser, Launch plan $0.10 per browser-hour; Browser, Scale plan $0.08 per browser-hour; Proxy traffic, Launch $10 per GB of traffic; Proxy traffic, Scale $6 per GB of traffic; Scrape, screenshot or PDF $5 per 1,000 requests; Scrape, screenshot or PDF by x402 $0.01 per call; CAPTCHA solves, Launch $3 per 1,000 requests; CAPTCHA solves, Scale $1 per 1,000 requests; Scale plan $250 per month (plan); Dedicated IP, Scale $5 per month (plan)

- Scores: Reliability 58, Performance pending, Schema & documentation 86, Agent ergonomics 79, Security & auth 56, Payments & pricing 75, Task success pending, Maintenance & community 82, Transparency & trust 64 · total over the 7 assessed categories
- Why: Reliability, Graded as a hosted service, on Steel Cloud. · Schema & documentation, OpenAPI 3.0.3 at docs.steel.dev/openapi.json with 51 paths and 75 operations and the `steel-api-key` header scheme (25). · Agent ergonomics, Scrape returns only the formats asked for (HTML, cleaned HTML, Markdown or readability text), lists take `limit`, and the MCP server holds i… · Security & auth, Named API keys, shown once, revoked by deletion, with last-used times and a rotation guide. · Payments & pricing, x402 version 2 at x402.steel.dev for scrape, screenshot and PDF, in USDC on Base or Solana. · Maintenance & community, Changelog 038 is dated 2 October 2026, and steel-browser's latest commit is 6 October (30). · Transparency & trust, Graded on the cloud service, which is closed with published terms.
- Sources: 37, open questions: 10, both in the full twin
- Capabilities: browser.control, browser.hosted, browser.debug, web.scrape, web.fetch, scraping.proxies, scraping.anti-bot, pdf.generate
- JSON: https://www.anchorterminal.com/api/v1/tools/steel.json
- Verify (for the vendor): the badge `https://www.anchorterminal.com/badges/steel.svg` or a link to https://www.anchorterminal.com/tools/steel from a page on steel.dev or one of its subdomains, or the README of github.com/steel-dev/steel-browser, 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. Use `POST /v1/scrape` for pages you only need to read. It starts no session and costs $5 per 1,000 calls, or $0.01 a call by x402
2. Release every session with `POST /v1/sessions/{id}/release` and set `inactivityTimeout`. Browser time bills by the minute, rounded up
3. Build the CDP URL as `wss://connect.steel.dev?apiKey=<key>&sessionId=<id>` and keep it out of logs, because it carries the key
4. Launch sessions end after 15 minutes at most, and `timeout` cannot be changed on a live session
5. CAPTCHA solving and Steel's managed proxies on Launch need $10 of paid balance. Free credit does not count

## Connect

```bash
npm install steel-sdk
```

```bash
curl -X POST https://api.steel.dev/v1/scrape -H "steel-api-key: YOUR_KEY" -H "Content-Type: application/json" -d '{"url": "https://example.com"}'
```

```bash
claude mcp add steel -e STEEL_API_KEY=your-steel-api-key -- npx -y github:steel-dev/steel-mcp-server
```

x402:

```bash
curl -i -X POST https://x402.steel.dev/v1/scrape -H "Content-Type: application/json" -d '{"url": "https://example.com", "format": ["markdown"]}'
```
Full config and headless snippets are in the full page. Through letme (picks today, calling later): https://letme.dev/steel

## Similar tools

| Tool | Grade | Score | Shared capabilities | Slim |
| --- | --- | --- | --- | --- |
| Anchor Browser | B | 67.3 | browser.control, browser.hosted, browser.debug, web.fetch, web.scrape, scraping.proxies, scraping.anti-bot, pdf.generate | https://www.anchorterminal.com/tools/anchor-browser.min.md |
| Browserless | BB | 70.4 | browser.control, browser.hosted, browser.debug, scraping.anti-bot, scraping.proxies, web.scrape, pdf.generate | https://www.anchorterminal.com/tools/browserless.min.md |
| Airtop | C | 55.3 | browser.control, browser.hosted, browser.debug, web.scrape, scraping.proxies, scraping.anti-bot | https://www.anchorterminal.com/tools/airtop.min.md |
| Spider | BB | 74.1 | web.scrape, web.fetch, browser.hosted, scraping.proxies, scraping.anti-bot | https://www.anchorterminal.com/tools/spider-cloud.min.md |
| Scrapfly | B | 69.6 | web.scrape, web.fetch, browser.hosted, scraping.proxies, scraping.anti-bot | https://www.anchorterminal.com/tools/scrapfly.min.md |


## Panel reviews (0, desk reviews from public material, no calls made)