Flask API utilizes blueprints for managing browsable pages' template path.

Off the box, it includes a default template. But you would want to customise this for your needs.

To do that, simply copy static and templates to your project.

Then override the previous blueprint with following:

from flask import Blueprint
from flask_api import FlaskAPI

theme = Blueprint(
    'flask-api', __name__,
    template_folder='templates', static_folder='static'

app = FlaskAPI(__name__)
app.blueprints['flask-api'] = theme

Use templates/base.html as your base custom template. Note that this cannot be renamed.