b4n1-web 0.9.3

B4n1Web Agentic Browser Engine - Ultra-lightweight headless browser for AI agents

B4n1Web Python SDK

Ultra-lightweight agentic browser engine with bundled binary. Navigate URLs, extract structured content (markdown, links, screenshots), and build AI agent workflows.

Install

pip install b4n1-web

No additional binary installation needed — the SDK bundles the b4n1web binary.

Quick Start

from b4n1web import AgentBrowser, BrowserMode

# Light mode - fastest
browser = AgentBrowser(mode=BrowserMode.LIGHT)
page = browser.goto("https://example.com")
print(page.markdown)
print(f"Found {len(page.links)} links")
browser.close()

# JS mode - extract scripts
browser = AgentBrowser(mode=BrowserMode.JS)
page = browser.goto("https://example.com")
browser.close()

# Render mode - full Chromium (requires chromium install)
# browser = AgentBrowser(mode=BrowserMode.RENDER)
# page = browser.goto("https://example.com")
# print(page.screenshot)  # base64 screenshot

Context Manager

with AgentBrowser() as browser:
    page = browser.goto("https://example.com")
    print(page.markdown)

Page Object

page.url          # str: final URL
page.markdown     # str: page content as markdown
page.links        # list[str]: all links on page
page.screenshot   # str|None: base64 screenshot (render mode)

page.get_main_content()           # str: content without headers
page.find_links_by_text("more")   # list[str]: links containing "more"

Browser Modes

Mode	Description	RAM	Startup
LIGHT	HTTP fetch + HTML parsing	~15MB	Instant
JS	Light + JavaScript extraction	~15MB	Instant
RENDER	Full Chromium + screenshots	~100MB	~2s

Security

from b4n1web.security import SecurityShield

shield = SecurityShield()
shield.mark_domain("evil.com", is_safe=False)
is_safe, needs_api = shield.is_url_safe("https://evil.com/page")
# (False, False)

MCP Integration

from b4n1web.mcp import AsyncMcpClient

async with AsyncMcpClient() as client:
    page = await client.goto("https://example.com")
    print(page.markdown)

Start MCP server:

b4n1web mcp -p 8080

Error Handling

from b4n1web import BinaryNotFoundError

try:
    browser = AgentBrowser()
except BinaryNotFoundError:
    print("b4n1web binary not found. Install with:")
    print("  curl -sL https://web.b4n1.com/install | bash")

Version

SDK version: 0.4.0 Bundled binary version: 0.4.0

Links

• PyPI
• GitHub
• Website

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