feat: add network request capture for browser agent

[nwang783]

Summary

Adds network request capture capability to the browser agent, enabling visibility into XHR/fetch API calls made by web applications.

Changes

New Files

• tempo/tools/network_capture.py - NetworkRequestCapture class that:

  • Captures XHR/fetch requests via CDP Network domain events
  • Fetches response bodies on-demand with size limits (1MB max)
  • Filters capturable content types (JSON, XML, HTML, JS, text)
  • Truncates output at 45k chars with auto-save to file

• tests/tools/test_network_capture.py - 20 unit tests (all passing)

Modified Files

• tempo/agents/browser.py - Added network_capture parameter to create_browser_use_agent()
• tempo/tools/browser_task_tool.py - Integrates NetworkRequestCapture with background CDP attachment
• tempo/tools/browser_use_adapter.py - Registers get_network_requests tool with async body fetching
• tempo/prompts/templates/browser_base.txt - Documents the new tool for the agent

New Tool: get_network_requests

get_network_requests(
    filter_type: str = "",        # "xhr", "fetch", "all"
    include_bodies: bool = False, # Fetch response bodies via CDP
    max_requests: int = 30
)

Use cases for security testing:

• Analyzing API endpoints and request/response patterns
• Capturing authentication tokens (bearer tokens, API keys, session cookies)
• Finding hidden API endpoints not visible in page source
• Understanding client-side API interactions on modern SPAs

Testing

python -m pytest tests/tools/test_network_capture.py -v
# 20 passed