.. _sec-api-general:

*******************
General information
*******************

.. contents::

.. _sec-api-general-authorization:

Authorization
=============

OctoPrint's API expects an API key to be supplied with each request. This API key can be either the globally
configured one, a user specific one if "Access Control" is enabled or an ref:`App Session Key <sec-api-apps-sessionkey>`.
Users are able to generate and revoke their custom API key via the "Change password" dialog.

The API key must be supplied in the custom HTTP header ``X-Api-Key``, e.g.

.. sourcecode:: http

   GET /api/files HTTP/1.1
   Host: example.com
   X-Api-Key: abcdef...

If it is missing or included but invalid, OctoPrint will directly return a response with status :http:statuscode:`401`.

For testing purposes it is also possible to supply the API key via a query parameter ``apikey``, e.g.

.. sourcecode:: http

   GET /api/files?apikey=abcdef... HTTP/1.1
   Host: example.com

Please be advised that clients should use the header field variant if at all possible.

.. _fig-api-general-globalapikey:
.. figure:: ../images/settings-global-api-key.png
   :align: center
   :alt: Global API key in the API settings

   The global API key can be found in the "API" settings

.. _fig-api-general-userapikey:
.. figure:: ../images/settings-user-api-key.png
   :align: center
   :alt: User specific API key location in user list

   The user list in the "Access Control" settings shows the API key for users (if available)

.. _fig-api-general-changepassword:
.. figure:: ../images/change-password-api-key.png
   :align: center
   :alt: API key options in "Change password" dialog

   The API key options in the "Change password" dialog. Users can generate and revoke their custom API key here.

.. note::
   OctoPrint's web interface uses a custom API key that is freshly generated on every server start. This key is not
   intended to be used by any other client and would not be very useful in any case, since it basically represents
   a completely anonymous client.

.. _sec-api-general-contenttype:

Content Type
============

If not otherwise stated OctoPrint's API expects request bodies and issues response bodies as ``Content-Type: application/json``.

.. _sec-api-general-encoding:

Encoding
========

OctoPrint uses UTF-8 as charset.

.. _sec-api-cross-origin:

Cross-origin requests
=====================

To make use of the OctoPrint API from websites other than the OctoPrint web interface,
cross-origin resource sharing (`CORS <http://en.wikipedia.org/wiki/Cross-origin_resource_sharing>`_) must be enabled.
This is the case even when the website in question is served from a different port on the same machine and on localhost.

To enable this feature, set the ``allowCrossOrigin`` key of the ``api`` section in ``config.yml`` to ``true`` or
check the corresponding checkbox in the API settings dialog.

.. code-block:: yaml

   api:
     enabled: true
     key: ...
     allowCrossOrigin: true

.. _fig-api-general-apicors:
.. figure:: ../images/settings-api-cors.png
   :align: center
   :alt: CORS configuration in the API settings

   Support for CORS can be enabled in the "API" settings

.. note::
   This means any browser page can send requests to the OctoPrint API. Authorization is still required however.

If CORS is not enabled you will get errors like the following::

   XMLHttpRequest cannot load http://localhost:8081/api/files. No 'Access-Control-Allow-Origin'
   header is present on the requested resource.

