User guide

Quick start

To run Turq, you need Python 3.4 or higher. Once you have that, install the turq package with pip:

$ pip3 install turq

Start Turq:

$ turq

You should see something like this:

18:22:19  turq  new rules installed
18:22:19  turq  mock on port 13085 - try http://pergamon:13085/
18:22:19  turq  editor on port 13086 - try http://pergamon:13086/
18:22:19  turq  editor password: QGOf9Y9Eqjvz4XhY4JA3U7hG (any username)

As you can see, Turq starts two HTTP servers. One is the mock server for the mocks you define. The other is the optional rules editor that makes writing mocks easier.

First you probably want to open the editor. By default, Turq listens on all network interfaces, so you can open the editor at http://localhost:13086/ in your Web browser. Turq also tries to guess and print a URL that doesn’t include localhost, which is useful when you run Turq on some remote machine via SSH.

Turq will ask you for the password that it generated and printed for you. You can leave the username field blank, it is ignored.


Anybody with access to the Turq editor can execute arbitrary code in the Turq process. The default password protection should keep you safe in most cases, but doesn’t help against an active man-in-the-middle. If that’s a problem, limit Turq to loopback with --bind localhost, or run without the editor.

In the editor, you define your mock by writing rules in the big code area, using the examples on the right as your guide. The default rules are just error(404), which means that the mock server will respond with 404 (Not Found) to every request. Let’s check that with curl:

$ curl -i http://pergamon:13085/some/page.html
HTTP/1.1 404 Not Found
content-type: text/plain; charset=utf-8
date: Tue, 04 Apr 2017 15:33:55 GMT
transfer-encoding: chunked

Error! Nothing matches the given URI

Keep an eye on the system console where you launched turq — all requests and responses are logged there:

19:01:30  turq.connection.1  new connection from
19:01:30  turq.request.1  > GET /some/page.html HTTP/1.1
19:01:30  turq.request.1  < HTTP/1.1 404 Not Found

When you are done, stop Turq by pressing Ctrl+C in the console.

That’s it, basically. Check turq --help for command-line options, or read on for more hints on how to use Turq.

Programmatic use

Turq was designed for interactive use; it trades precision for convenience and simplicity. However, you can use it non-interactively if you like:

$ turq --no-editor --rules /path/to/

Give it a second to spin up, or just loop until you can connect() to it. Shut it down with SIGTERM like any other process:

$ pkill turq

It goes without saying that Turq can’t be used anywhere near production.

Using mitmproxy with Turq

Put mitmproxy in front of Turq to:

  • enable TLS (https) access to the mock server;
  • inspect all requests and responses in detail;
  • validate them with HTTPolice; and more.

Assuming Turq runs on the default port, use a command like this:

$ mitmproxy --port 13185 --reverse http://localhost:13085

Then tell your client to connect to port 13185 (http or https) instead of 13085.

Known issues

Password protection in the rules editor does not work well in some browsers. For example, you may randomly get “Connection error” in Internet Explorer. To avoid this, you can disable password protection with -P "", but be sure to have some other protection instead.

The mock server doesn’t send any cache-related headers by default. As a result, some browsers may cache your mocks, leading to strange results. You can disable caching in your rules:

add_header('Cache-Control', 'no-store')

Turq has limited options to control the addresses it listens on. You can forward its ports manually with socat or mitmproxy.