Support Cross Origin Resource Sharing (CORS) in a Flask App without an extra extension¶

This article shows how to support cross-origin requests in a Flask app when you DO NOT want an extension like Flask-CORS.

Code example¶

from flask import Flask

app = Flask(__name__)

@app.after_request
def set_cors(resp):
    resp.headers["Access-Control-Allow-Origin"] = "*"
    resp.headers["Access-Control-Allow-Methods"] = "*"
    resp.headers["Access-Control-Allow-Headers"] = "*"
    resp.headers["Access-Control-Max-Age"] = "600" # 600 seconds
    return resp

You may tune the response headers as needed.