API documentation¶

APIFlask provides support to the following API documentation UIs:

Change the documentation UI library¶

The docs UI is controlled via the docs_ui parameter when creating the APIFlask instance:

from apiflask import APIFlask

app = APIFlask(__name__, docs_ui='redoc')

The following values can be used:

swagger-ui (default value)
redoc
elements
rapidoc
rapipdf

Change the path to API documentation¶

The default path of API documentation is /docs, so it will be available at http://localhost:5000/docs when running on local with the default port. You can change the path via the docs_path parameter when creating the APIFlask instance:

from apiflask import APIFlask

app = APIFlask(__name__, docs_path='/api-docs')

The docs_path accepts a URL path starts with a slash, so you can set a prefix like this:

from apiflask import APIFlask

app = APIFlask(__name__, docs_path='/openapi/docs')

Now the local URL of the docs will be http://localhost:5000/openapi/docs.

You can also set openapi_blueprint_url_prefix to add a prefix to all OpenAPI-related paths.

from apiflask import APIFlask

app = APIFlask(__name__, openapi_blueprint_url_prefix='/openapi')

Now the paths to docs and spec will be http://localhost:5000/openapi/docs and http://localhost:5000/openapi/openapi.json.

Add authentication to API documentation¶

See Protect OpenAPI endpoints for more details.

Add custom API documentation¶

You can easily add support to other API docs or serve the supported docs UI by yourself.

Just create a view to render the docs template, take Redoc as an example:

from apiflask import APIFlask
from flask import render_template

app = APIFlask(__name__)


@app.route('/redoc')
def my_redoc():
    return render_template('/redoc.html')

Here is the template redoc.html:

<!DOCTYPE html>
<html>
  <head>
    <title>My Redoc</title>
    <meta charset="utf-8"/>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link href="https://fonts.googleapis.com/css?family=Montserrat:300,400,700|Roboto:300,400,700" rel="stylesheet">

    <style>
      body {
        margin: 0;
        padding: 0;
      }
    </style>
  </head>
  <body>
    <redoc spec-url="{{ url_for('openapi.spec') }}"></redoc>
    <script src="https://cdn.redoc.ly/redoc/latest/bundles/redoc.standalone.js"> </script>
  </body>
</html>

In the template, we use {{ url_for('openapi.spec') }} to get the URL to the OpenAPI spec file.

Now visit http://localhost:5000/redoc, you will see your custom Redoc API docs.

In this way, you can serve multiple API docs at the same time, or add auth protect to the docs view. If you want to use the built-in configuration variable for API docs or just want to write less code, you can import the API docs template directly from APIFlask:

from apiflask import APIFlask
from apiflask.ui_templates import redoc_template
from flask import render_template_string

app = APIFlask(__name__)


@app.route('/redoc')
def my_redoc():
    return render_template_string(redoc_template, title='My API', version='1.0')

Disable the API documentation globally¶

You can set the docs_path parameter to None to disable the API documentation:

from apiflask import APIFlask

app = APIFlask(__name__, docs_path=None)

Tip

If you want to disable the whole OpenAPI support for the application, see Disable the OpenAPI support for more details.

Disable the API documentations for specific blueprints¶

See Disable the OpenAPI support for specific blueprints for more details.

Disable the API documentations for specific view functions¶

See Disable the OpenAPI support for specific view functions for more details.

Configure API documentations¶

The following configuration variables can be used to configure API docs:

DOCS_FAVICON
REDOC_USE_GOOGLE_FONT
REDOC_CONFIG
SWAGGER_UI_LAYOUT
SWAGGER_UI_CONFIG
SWAGGER_UI_OAUTH_CONFIG
ELEMENTS_LAYOUT
ELEMENTS_CONFIG
RAPIDOC_THEME
RAPIDOC_CONFIG
RAPIPDF_CONFIG

See Configuration for the introduction and examples of these configuration variables.

Use different CDN server for API documentation resources¶

Each resource (JavaScript/CSS files) URL has a configuration variable. You can pass the URL from your preferred CDN server to the corresponding configuration variables:

REDOC_STANDALONE_JS
SWAGGER_UI_CSS
SWAGGER_UI_BUNDLE_JS
SWAGGER_UI_STANDALONE_PRESET_JS
RAPIDOC_JS
ELEMENTS_JS
ELEMENTS_CSS
RAPIPDF_JS

Here is an example:

# Swagger UI
app.config['SWAGGER_UI_CSS'] = 'https://cdnjs.cloudflare.com/ajax/libs/swagger-ui/4.11.1/swagger-ui.min.css'
app.config['SWAGGER_UI_BUNDLE_JS'] = 'https://cdnjs.cloudflare.com/ajax/libs/swagger-ui/4.11.1/swagger-ui-bundle.min.js'
app.config['SWAGGER_UI_STANDALONE_PRESET_JS'] = 'https://cdnjs.cloudflare.com/ajax/libs/swagger-ui/4.11.1/swagger-ui-standalone-preset.min.js'
# Redoc
app.config['REDOC_STANDALONE_JS'] = 'https://cdn.redoc.ly/redoc/latest/bundles/redoc.standalone.js'
# Elements
app.config['ELEMENTS_JS'] = 'https://cdn.jsdelivr.net/npm/@stoplight/elements-dev-portal@1.7.4/web-components.min.js'
app.config['ELEMENTS_CSS'] = 'https://cdn.jsdelivr.net/npm/@stoplight/elements-dev-portal@1.7.4/styles.min.css'
# RapiDoc
app.config['RAPIDOC_JS'] = 'https://cdn.jsdelivr.net/npm/rapidoc@9.3.2/dist/rapidoc-min.min.js'
# RapiPDF
app.config['RAPIPDF_JS'] = 'https://cdn.jsdelivr.net/npm/rapipdf@2.2.1/src/rapipdf.min.js'

See Configuration for the introduction and examples of these configuration variables.

Serve API documentation from local resources¶

Like what you need to do in the last section, to use local resources, you can pass the URL of local static files to the corresponding configuration variables:

REDOC_STANDALONE_JS
SWAGGER_UI_CSS
SWAGGER_UI_BUNDLE_JS
SWAGGER_UI_STANDALONE_PRESET_JS
RAPIDOC_JS
ELEMENTS_JS
ELEMENTS_CSS
RAPIPDF_JS

For local resources, you can pass a relative URL. For example, if you want to host the Redoc standalone JavaScript file from a local file, follow the following steps:

Manual download file:

Download the file from CDN server.
Put the file in your static folder, name it as redoc.standalone.js or whatever you want.
Figure out the relative URL to your js file. If the file sits in the root of the static folder, then the URL will be /static/redoc.standalone.js. If you put it into a subfolder called js, then the URL will be /static/js/redoc.standalone.js.

Pass the URL to the corresponding config:

app.config['REDOC_STANDALONE_JS'] = '/static/js/redoc.standalone.js'

Tip

The static part of the URL matches the static_url_path argument you passed to the APIFlask class, defaults to static.

Or with npm:

Initialize the npm in static folder with npm init.
Install the file via npm i redoc command.

Pass the URL to the corresponding config:

app.config['REDOC_STANDALONE_JS'] = 'static/node_modules/redoc/bundles/redoc.standalone.js'

Tip

The resources of Swagger UI can be found at the dist folder of release assets at Swagger UI releases page.

Standalone Static HTML documentation¶

For offline use, you can generate the OpenAPI docs as PDF with RapiPDF:

from apiflask import APIFlask

app = APIFlask(__name__, docs_ui='rapipdf')

If the generated PDF file is not meeting your requirements, you can also serve a static HTML file as the API documentation.

Take Swagger UI as an example, you will need to:

Create a static HTML file that loads Swagger UI JavaScript and CSS files.

Generate a local OpenAPI spec file with the flask spec command. Set the following configuration:

app.config['SYNC_LOCAL_SPEC'] = True  # keep the spec file up-to-date with code
app.config['LOCAL_SPEC_PATH'] = 'openapi.json'  # the path to the spec file
app.config['LOCAL_SPEC_JSON_INDENT'] = 0  # set to 0 to remove indentation

Create a shell script to read the OpenAPI spec file and pass it to Swagger UI HTML file. For example:

#!/bin/sh

spec_value=$(python3 -c "import json; print(open('openapi.json').read())")
# Replace var spec = {...} line in index.html
sed -i "s|var spec = {.*}|var spec = $spec_value|g" index.html

Here is a full example.

See also the Swagger UI documentation for the standalone installation.