pybrws

Python + browser: an HTTPS client that sends what a real browser sends

pybrws is written from scratch in Python. It sends what Firefox 157 and Chrome 155 send on the wire: the TLS ClientHello, the HTTP/2 start and the headers. It also sends Firefox's QUIC hello over HTTP/3. It is a learning and measurement tool that you can install, and it began as a way to see how browsers look on the wire.

It is not a replacement for curl_cffi. For production use, use curl_cffi. pybrws makes no promise that any site will accept its requests.

Install

pip install pybrws

Python 3.11 or newer. Two optional extras:

• pip install "pybrws[http3]" adds aioquic, for HTTP/3.
• pip install "pybrws[measure]" adds httpx, for the A/B controls of pybrws ab.

Use it from Python

from pybrws.client import get
from pybrws.profiles import chrome155

response = get("https://example.com/", profile=chrome155)
print(response.status, response.header("content-type"))
print(response.text()[:200])

The default profile is firefox157. post and request work the same way. HTTP/3 is pybrws.h3.get(url), Firefox only.

Use it from the command line

pybrws https://example.com/
pybrws verify --local

The first fetches a page like curl. The second compares the default profile's ClientHello with the browser capture shipped in the package, offline, and prints "same string as the capture". Other subcommands: capture, read-quic, ja4, verify, probe, ab, isolate, waf.

More

• Documentation: https://pybrws.readthedocs.io/
• Source: https://github.com/epcosta17/pybrws
• Licence: MIT