HTTP/2 Async Client written with h2, for tornado

async, h2, http2, python, tornado
pip install th2c==0.4.1


Async HTTP/2 Client

A simple asynchronous HTTP/2 client for Tornado applications, based on the awesome h2 library.

Intended for Python 2 (>= 2.7.9).

This package is in a very early development stage, so expect bugs or changes in the API. If you spot anything wrong, or would like to suggest improvements, please open an issue or a pull request.


Usage in a coroutine may be:

from th2c import AsyncHTTP2Client
from tornado.httpclient import HTTPRequest

client = AsyncHTTP2Client(
    host='', port=443, secure=True,

request = HTTPRequest(

res = yield client.fetch(request)


  • moar tests :)
  • follow_redirects
  • priority control

Development setup

If you wish to create a development environment to work on th2c, you can use a Vagrant setup or a virtual environment. The Vagrant setup is located under vm, an Ubuntu 16.04 64bit box with Go and Python 2 installed, that maps the project directory under /opt/dev/th2c.

For a minimal set of "integration tests", a Go web server is included in test_server that simply echoes back what it receives.

You can run it in debug mode, from the project directory, by executing:

GODEBUG=http2debug=1 go run test_server/main.go.

After the server has started, you should run the client by executing:

python -m th2c.

Log files should be produced under /opt/dev/th2c/logs.

You can also run unit tests with: nosetests tests