Add prefix to all URLs while using Blueprint

Question

I am trying to prefix all endpoints with /api/, but I am getting 404 in return if not providing directly in the URL or while registering blueprint.

main.py

from init import app

from modules.User import User

app.register_blueprint(User)

if __name__ == "__main__":
    app.run(debug=True)

init.py

from flask import Flask

# initiating application instance
app = Flask(__name__)

# app configurations
app.config["SCRIPT_NAME"] = "/api/"

# -- OR --

app.config["APPLICATION_ROOT"] = "/api/"
...

modules/User.py

from flask import request, Blueprint

User = Blueprint("user_blueprint", __name__)

# if "/api/" is provided directly 
@User.route("/api/", methods=["GET"]) 
def get():
    return "Called get method"


# 404 if "/" is provided
@User.route("/", methods=["GET"]) 
def get():
    return "Called get method"

Answer 1

APPLICATION_ROOT and SCRIPT_NAME define the base path where the application is mounted by the WSGI server.

They don’t automatically add /api to your routes during development, so your @User.route("/") ends up at /, not /api/, hence you get the 404.

You can achieve the desired behavior in one of the following ways:

• use url_prefix on the blueprint

  Use:

  # modules/User.py
  User = Blueprint("user_blueprint", __name__, url_prefix="/api")
  

  Instead of:

  # modules/User.py
  User = Blueprint("user_blueprint", __name__)
  

  Code:

  # main.py
  from init import app
  from modules.User import User
  
  app.register_blueprint(User)
  
  
  if __name__ == "__main__":
      app.run(debug=True)
  

  # init.py
  from flask import Flask
  
  # initiating application instance
  app = Flask(__name__)
  

  # modules/User.py
  from flask import request, Blueprint
  
  User = Blueprint("user_blueprint", __name__, url_prefix="/api")
  
  @User.route("/", methods=["GET"])
  def get():
      return "Called get method"
  
  @User.route("/data", methods=["GET"])
  def data():
      return "Called data method"
  

  python main.py
  
  >> curl http://127.0.0.1:5000/api/
  Called get method
  >> curl http://127.0.0.1:5000/api/data
  Called data method
  

• or use url_prefix when registering it

  Use:

  # main.py
  app.register_blueprint(User, url_prefix="/api")
  

  Instead of:

  # main.py
  app.register_blueprint(User)
  

  Code:

  # main.py
  from init import app
  from modules.User import User
  
  app.register_blueprint(User, url_prefix="/api")
  
  
  if __name__ == "__main__":
      app.run(debug=True)
  

  # init.py
  from flask import Flask
  
  # initiating application instance
  app = Flask(__name__)
  

  # modules/User.py
  from flask import Blueprint
  
  User = Blueprint("user_blueprint", __name__)
  
  @User.route("/", methods=["GET"])
  def get():
      return "Called get method"
  
  @User.route("/data", methods=["GET"])
  def data():
      return "Called data method"
  

  python main.py
  
  >> curl http://127.0.0.1:5000/api/
  Called get method
  >> curl http://127.0.0.1:5000/api/data
  Called data method