dark-swag 0.0.1

Dark mode Swagger for your FastAPI apps

DarkSwag

Get dark-mode Swagger (OpenAPI) docs for FastAPI without having to modify anything. DarkSwag has an optional argument for adding a logo to the top right.

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Installation

python -m pip install dark_swag

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Implementation

There are three main ways you can implement this into your API.

1. The easiest is to import the FastAPI override, as it requires no additional change to your existing code.

   from dark_swag import FastAPI
   
   app = FastAPI()
   

   • Full example of this implementation

2. You can import the get_dark_router factory function to generate a route that you can immediately add to your existing FastAPI instance.

   from fastapi import FastAPI
   from dark_swag import get_dark_router
    
   app = FastAPI(docs_url=None) # this argument is required if you use this implementation
   app.include_router(get_dark_router(app))
   

   • Full example of this implementation

3. You can manually define the docs route yourself, and use the helper function to generate the dark-enabled html.

   from fastapi import FastAPI
   from dark_swag import get_dark_swagger_html
   
   app = FastAPI(docs_url=None) # this argument is required if you use this implementation
    
   @app.get('/docs', include_in_schema=False)
   async def dark_swagger():
       return get_dark_swagger_html(app)
   

   • Full example of this implementation

Be sure to add docs_url=None to your FastAPI instantiation if you use methods #2 or #3, else this won't work, since FastAPI will generate the /docs endpoint internally and your manual definition of it won't overwrite it.

This is still 100% Swagger. We just inject CSS to create the dark theme in-flight before it's sent to the caller.

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Features

Custom Logo

You can add your own logo to the top-right corner of the Swagger doc by passing a URL or path to an image to the argument logo.

You'll probably need to make a route to host them from, or you can also pass in the image as base64 format like this:

1. If you used the FastAPI override, you add the argument to it:

   # mounted path, like a FastAPI static endpoint
   app = FastAPI(logo='static/logo.png')
   
   """ OR """
   
   # raw base64 string with the appropriate prefix (below example is for an SVG)
   app = FastAPI(logo="data:image/svg+xml;base64,xucz0i... (shortened for illustration) ...L3d3dy")
   

2. If you used the dark_router, you add the argument to the factory function:

   dark_router = get_dark_router(app, logo='static/logo.png')
   

3. If you used the helper function to get the Swagger HTML and manually defined your /docs endpoint, you add the argument to that helper function:

   return get_dark_swagger_html(app, logo='static/logo.png')
   

The logo placement looks like this:

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Background Text

Like the above logo, this is also purely for aesthetics. You basically can pass in a word or short phrase, and it gets drawn on the background in a watermark-like fashion, purely to help branding or for aesthetics. Longer text will probably get truncated due to how this effect was accomplished.

1. If you used the FastAPI override, you add background_text argument with it:

   app = FastAPI(background_text='Example 3')
   

2. If you used the dark_router, you add the background_text argument to it:

   dark_router = get_dark_router(app, background_text='Example 3')
   

3. If you used the helper function get_dark_swagger_html, you do the same thing:

   return get_dark_swagger_html(app, background_text='Example 3')
   

The text looks like this:

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Aziz, light!

For our friends and colleagues that enjoy being flashbanged when they open documentation, this option is for toggling light mode. There's a toggle button at the top right. Implementation methods #2 and #3 support this without doing anything extra.

If you set DarkSwag up using the completely manual method #3, you need to define both /docs and /docs_light routes, as this just links between the two. See example3.py for a working example of this.

If you click the Light Mode toggle at the top right, it will enable light mode, and it will look very similar to the standard Swagger docs, only it still supports the addition of your own logo and the watermark-like background text. There's also a toggle for switching back to dark mode. The toggle isn't toggling CSS. It's just linking back and forth between /docs and /docs_light.

Here's what light mode looks like:

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Notes

Technically, there is a "cleaner" way to do this. FastAPI provides a function you can call that generates the swagger doc, and you can pass in the javascript and css files, so there's an opportunity to feed it your own.

The reason why I did NOT go this route, is simply due to practicality. Once de-minified, the Swagger style sheet is 11,490 lines long when pretty-printed. It's obviously built from a packager and coalesced into a single file, with media queries to cover all bases, so it's no surprise why it can be so massive, but I wasn't about to invest that much time on this, so I went the route that most do: inject override CSS into the head before you return the HTMLResponse. It's pretty limiting only being able to touch CSS, but I was still able to figure some things out like toggling light/dark modes, and allowing for an optional custom logo.

If anyone has a better plan, feel free to contribute. It's hard to test all possible cases as OpenAPI supports a ton of stuff, so there's a good chance some things might not be fully adjusted for dark mode, but they're easy to add as they're found.

Bananas, isn't it?