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+.. _overview:
+
+Overview
+=========
+
+Mitmproxy has a powerful scripting API that allows you to control almost any
+aspect of traffic being proxied. In fact, much of mitmproxy's own core
+functionality is implemented using the exact same API exposed to scripters (see
+:src:`mitmproxy/builtins`).
+
+Scripting is event driven, with named handlers on the script object called at
+appropriate points of mitmproxy's operation. Here's a complete mitmproxy script
+that adds a new header to every HTTP response before it is returned to the
+client:
+
+.. literalinclude:: ../../examples/add_header.py
+   :caption: :src:`examples/add_header.py`
+   :language: python
+
+All events that deal with an HTTP request get an instance of
+:py:class:`~mitmproxy.models.HTTPFlow`, which we can use to manipulate the
+response itself. We can now run this script using mitmdump or mitmproxy as
+follows:
+
+>>> mitmdump -s add_header.py
+
+The new header will be added to all responses passing through the proxy.
+
+
+mitmproxy comes with a variety of example inline scripts, which demonstrate
+many basic tasks.
+
+
+Running scripts in parallel
+---------------------------
+
+We have a single flow primitive, so when a script is blocking, other requests are not processed.
+While that's usually a very desirable behaviour, blocking scripts can be run threaded by using the
+:py:obj:`mitmproxy.script.concurrent` decorator.
+**If your script does not block, you should avoid the overhead of the decorator.**
+
+.. literalinclude:: ../../examples/nonblocking.py
+   :caption: examples/nonblocking.py
+   :language: python
+
+Make scripts configurable with arguments
+----------------------------------------
+
+Sometimes, you want to pass runtime arguments to the inline script. This can be simply done by
+surrounding the script call with quotes, e.g. ```mitmdump -s 'script.py --foo 42'``.
+The arguments are then exposed in the start event:
+
+.. literalinclude:: ../../examples/modify_response_body.py
+   :caption: examples/modify_response_body.py
+   :language: python
+
+
+Running scripts on saved flows
+------------------------------
+
+Sometimes, we want to run a script on :py:class:`~mitmproxy.models.Flow` objects that are already
+complete.  This happens when you start a script, and then load a saved set of flows from a file
+(see the "scripted data transformation" example :ref:`here <mitmdump>`).
+It also happens when you run a one-shot script on a single flow through the ``|`` (pipe) shortcut
+in mitmproxy.
+
+In this case, there are no client connections, and the events are run in the following order:
+**start**, **request**, **responseheaders**, **response**, **error**, **done**.
+If the flow doesn't have a **response** or **error** associated with it, the matching events will
+be skipped.
+
+Spaces in the script path
+-------------------------
+
+By default, spaces are interpreted as a separator between the inline script and its arguments
+(e.g. ``-s 'foo.py 42'``). Consequently, the script path needs to be wrapped in a separate pair of
+quotes if it contains spaces: ``-s '\'./foo bar/baz.py\' 42'``.
+
+.. _GitHub: https://github.com/mitmproxy/mitmproxy