FastAPI is famous for its blazing speed and auto-generated documentation.

Out of the box, it gives you:

• Swagger UI at /docs
• ReDoc UI at /redoc

But here’s the thing:

If you want your API to feel polished, developer-friendly, and production-ready,

you need better documentation than just the basics.

Today, I’ll show you how to use scalar-fastapi to create beautiful, customizable API docs — and why great documentation is as important as great code.

🛠 The Problem with Default Swagger Docs

Swagger is great for getting started, but:

• It's plain and developer playground-like
• It doesn't scale visually when you have 50+ endpoints
• It lacks branding — it doesn't feel like your product
• First impressions matter — messy docs = perceived messy product

🚀 Meet scalar-fastapi

scalar-fastapi is a sweet package that upgrades your FastAPI documentation experience instantly.

It turns your OpenAPI schema into a:

• Beautifully designed API reference
• Modern, responsive UI
• Developer-first experience

And the best part?

It takes just a few lines of code to integrate.

📦 How To Set It Up

First, install Scalar:

pip install scalar-fastapi

Now update your main.py:

from fastapi import FastAPI
from app.core.config import settings
from app.api.v1 import router as v1_router
from scalar_fastapi import get_scalar_api_reference

app = FastAPI(title=settings.PROJECT_NAME)

app.include_router(v1_router, prefix=settings.API_V1_STR)

@app.get("/")
def read_root():
    return {"message": "Welcome to the FastAPI backend!"}

@app.get("/scalar", include_in_schema=False)
async def scalar_html():
    return get_scalar_api_reference(
        openapi_url=app.openapi_url,
        title=app.title,
    )

✅ That’s it — now visiting /scalar will show you the upgraded docs!

🎨 Before and After — Visual Impact

A small upgrade that changes the entire experience.

🛠 Full Configuration Options (Explained)

Scalar gives you serious control over how your docs look and behave:

🔥 Example: Fully Customized Scalar UI

from scalar_fastapi import get_scalar_api_reference, Layout, SearchHotKey

@app.get("/scalar", include_in_schema=False)
async def scalar_html():
    return get_scalar_api_reference(
        openapi_url=app.openapi_url,
        title="My Awesome API",
        layout=Layout.CLASSIC,
        show_sidebar=True,
        hide_download_button=False,
        hide_models=False,
        dark_mode=True,
        search_hot_key=SearchHotKey.K,
        servers=[
            {"url": "https://api.production.example.com"},
            {"url": "https://api.staging.example.com"}
        ],
        default_open_all_tags=True,
        authentication={"bearerAuth": "your-static-token-if-needed"},
    )

Boom — your docs now:

• Match your brand
• Show your production & staging servers
• Look polished out of the box

🌍 Bonus: Deploying Your Public Docs

After setting up Scalar, you might want to expose your API docs nicely.

Here are two easy ways:

• Docker Deploy: Serve your FastAPI app inside a Docker container behind nginx.
• Cloud Deploy: Push it to AWS, Koyeb or DigitalOcean for HTTPS and autoscaling.

FastAPI + Scalar scales to real production traffic easily.

📣 Why Beautiful API Docs Matter

Good docs aren't just about looking nice:

✅ They save onboarding time for new devs

✅ They reduce mistakes using the API

✅ They build trust in your platform

✅ They differentiate you from lazy competitors

In real startups and production teams, beautiful docs = better adoption.

That's why companies like Stripe, Twilio, and Shopify invest heavily into theirs.

🏁 Final Thoughts

✅ If you're serious about building professional APIs

✅ If you care about other developers using your platform

✅ If you want to stand out

Then upgrading your FastAPI docs with Scalar is one of the easiest, most impactful things you can do today.

It takes 5 minutes, but leaves a permanent pro impression.

🚀 What's Next?

In the next part of this series, I’ll show how to:

• Tag your endpoints for even cleaner documentation
• Add authentication flows (JWT, OAuth) to your docs
• Customize OpenAPI metadata (terms, license, support contacts)

Stay tuned — we’re building real production-ready APIs! 🎯

✍️ Final CTA

"If you enjoyed this guide, connect with me on LinkedIn for more full-stack engineering, and developer experience tips!" 🚀