steel-browser（钢浏览器）

Steel

Cloud browser infrastructure for AI agents. Steel gives your agent a real browser that can navigate pages, fill forms, solve CAPTCHAs, and extract content.

If Steel is not installed yet, execute the setup steps below autonomously. Only ask the user to do one thing: click the authentication link.

OBJECTIVE: Install the Steel CLI, authenticate, and verify everything works.

DONE WHEN: steel scrape https://example.com returns page content successfully.

Setup

Step 1: Install Steel CLI

Check if steel is already available:

steel --version

If the command is not found, install it:

curl -sSf https://setup.steel.dev/install.sh | sh
export PATH="$HOME/.steel/bin:$PATH"

Step 2: Authenticate

If STEEL_API_KEY is already set in the environment, skip this step.

Otherwise, run:

steel login

This will print a URL. Ask the user to click the link to complete authentication. Wait for the command to finish — it will print "Authentication successful" when the user has approved.

Step 3: Verify

steel scrape https://example.com

This should return Markdown content. If it does, setup is complete.

Choose the right tool

Start with steel scrape when you only need page content. Escalate to steel browser when the page requires interaction or JavaScript rendering.

API tools (one-shot, no session needed)

# Scrape — returns Markdown by default (use --json flag for structured output)
steel scrape https://example.com
steel scrape https://example.com --format html
steel scrape https://example.com --use-proxy

# Screenshot
steel screenshot https://example.com
steel screenshot https://example.com --full-page

# PDF
steel pdf https://example.com

Interactive browser session

Core workflow

1. Start a named session
2. Navigate to the target URL
3. Snapshot to get page state and element refs
4. Interact using @eN refs from the snapshot
5. Re-snapshot after every navigation or DOM change (refs expire)
6. Stop the session when done

steel browser start --session my-task --session-timeout 3600000
steel browser navigate https://example.com --session my-task
steel browser snapshot -i --session my-task
steel browser fill @e3 "search term" --session my-task
steel browser click @e7 --session my-task
steel browser wait --load networkidle --session my-task
steel browser snapshot -i --session my-task
steel browser stop --session my-task

Rules:

• Always use the same --session <name> on every command.
• Never use an @eN ref without a fresh snapshot — refs expire after navigation or DOM changes.
• Prefer element refs from snapshot -i over CSS selectors. Use -c for large DOMs, -d 3 to limit depth.
• Use batch to combine multiple commands into a single invocation for efficiency.

Batch execution

Run multiple commands in one CLI call. Each quoted string is one command.

# Navigate and snapshot in one call
steel browser batch "navigate https://example.com" "snapshot -i" --session my-task

# Action + re-snapshot (no separate snapshot call needed)
steel browser batch "click @e3" "snapshot -i" --session my-task

# Multiple actions without intermediate snapshots
steel browser batch "fill @e1 Seoul" "fill @e2 Tokyo" "click @e5" --session my-task

# Stop on first error with --bail
steel browser batch "click @e3" "snapshot -i" --session my-task --bail

Use batch when:

• You need to snapshot after an action (most common case)
• You are filling multiple form fields in sequence
• You want to reduce the number of CLI invocations

Use separate commands when you need to read the output of one command before deciding the next.

Session lifecycle

steel browser start --session <name> --session-timeout 3600000
steel browser start --session <name> --stealth
steel browser start --session <name> --proxy <url>
steel browser sessions
steel browser live --session <name>
steel browser stop --session <name>
steel browser stop --all

Navigation and inspection

steel browser navigate <url> --session <name>
steel browser snapshot                         # full accessibility tree
steel browser snapshot -i                      # interactive elements + refs
steel browser snapshot -c                      # compact output
steel browser snapshot -i -c -d 3             # combine flags
steel browser get url --session <name>
steel browser get title --session <name>
steel browser get text @e1 --session <name>
steel browser back --session <name>
steel browser forward --session <name>
steel browser reload --session <name>

Interaction

steel browser click @e1 --session <name>
steel browser dblclick @e1 --session <name>
steel browser fill @e2 "value" --session <name>
steel browser type @e2 "value" --delay 50 --session <name>
steel browser press Enter --session <name>
steel browser press Control+a --session <name>
steel browser hover @e1 --session <name>
steel browser select @e1 "option" --session <name>
steel browser scroll down 500 --session <name>
steel browser scrollintoview @e1 --session <name>
steel browser drag @e1 @e2 --session <name>
steel browser tab new --session <name>
steel browser tab switch 2 --session <name>
steel browser tab list --session <name>
steel browser tab close --session <name>

Synchronization

steel browser wait --load networkidle --session <name>
steel browser wait --selector ".loaded" --state visible --session <name>
steel browser wait -t "Success" --session <name>
steel browser wait -u "/dashboard" --session <name>

Extraction

steel browser get text @e1 --session <name>
steel browser get html @e1 --session <name>
steel browser get value @e1 --session <name>
steel browser get attr @e1 href --session <name>
steel browser get count ".item" --session <name>
steel browser content --session <name>
steel browser eval "document.querySelectorAll('a').length" --session <name>
steel browser find ".item" --session <name>

Screenshots (in-session)

steel browser screenshot -o ./page.png --session <name>
steel browser screenshot --full --session <name>
steel browser screenshot --selector "#chart" --session <name>

Top-level steel screenshot <url> and steel pdf <url> are stateless one-shot API calls — they do not take --session or -o flags. Use steel browser screenshot for in-session captures.

Cookies and storage

steel browser cookies --session <name>
steel browser cookies set <name> <value> --session <name>
steel browser cookies set <name> <value> --domain .example.com
steel browser cookies clear --session <name>
steel browser storage session --session <name>
steel browser storage session set authToken "abc123" --session <name>

Browser settings

steel browser set viewport 1920 1080 --session <name>
steel browser set geo 37.7749 -122.4194 --session <name>
steel browser set offline on --session <name>
steel browser set useragent "Custom UA" --session <name>

CAPTCHA

steel browser start --session <name> --stealth
steel browser captcha status --wait --session <name>
steel browser captcha solve --session <name>

eval for capability gaps

Use steel browser eval "<js>" --session <name> when no direct command exists. Common uses: network interception, DOM state injection, complex form widgets.

Commands that do NOT exist

Do not attempt these — they will fail.

SDK integration (programmatic)

If you need to use Steel from code instead of the CLI:

Python (Playwright)

pip install steel-sdk playwright

from playwright.sync_api import sync_playwright
from steel import Steel
import os

client = Steel(steel_api_key=os.environ["STEEL_API_KEY"])
session = client.sessions.create()

try:
    pw = sync_playwright().start()
    browser = pw.chromium.connect_over_cdp(session.websocket_url)
    page = browser.contexts[0].pages[0]

    page.goto("https://example.com")
    print(page.title())
finally:
    browser.close()
    pw.stop()
    client.sessions.release(session.id)

Node.js (Puppeteer)

npm install steel-sdk puppeteer

import Steel from 'steel-sdk';
import puppeteer from 'puppeteer';

const client = new Steel({ steelAPIKey: process.env.STEEL_API_KEY });
const session = await client.sessions.create();

try {
  const browser = await puppeteer.connect({
    browserWSEndpoint: `${session.websocketUrl}?apiKey=${process.env.STEEL_API_KEY}`,
  });
  const page = await browser.newPage();
  await page.goto('https://example.com');
  console.log(await page.title());
  await browser.disconnect();
} finally {
  await client.sessions.release(session.id);
}

Key pattern: Create session → connect via CDP websocket URL → use any browser library → release session.

Troubleshooting

If you run into issues, refer to https://docs.steel.dev or run steel --help.