Where do I get a SECRET_KEY for Flask?

I am trying to set up Flask-Debugtoolbar, but I get the message "DebugToolBar requires a SECRET_KEY". Where do I get the secret key?

5 Answers

Get the random string for secret key:

Method 1: Use os in Python 2/3:

>>> import os >>> os.urandom(12) '\xf0?a\x9a\\\xff\xd4;\x0c\xcbHi' 

Method 2: Use uuid in Python 2/3:

>>> import uuid >>> uuid.uuid4().hex '3d6f45a5fc12445dbac2f59c3b6c7cb1' 

Method 3: Use secrets in Python >= 3.6:

>>> import secrets >>> secrets.token_urlsafe(16) 'Drmhze6EPcv0fN_81Bj-nA' >>> secrets.token_hex(16) '8f42a73054b1749f8f58848be5e6502c' 

Method 4: Use os in Python 3:

>>> import os >>> os.urandom(12).hex() 'f3cfe9ed8fae309f02079dbf' 

Set secret key in Flask

Method 1: Use app.secret_key:

app.secret_key = 'the random string' 

Method 2: Use app.config:

app.config['SECRET_KEY'] = 'the random string' 

Method 3: Put it in your config file:

SECRET_KEY = 'the random string' 

Then load the config form config file:

app.config.from_pyfile('config.py') # if your config file's name is config.py 

The secret key is needed to keep the client-side sessions secure. You can generate some random key as below:

>>> import os >>> os.urandom(24) '\xfd{H\xe5<\x95\xf9\xe3\x96.5\xd1\x01O<!\xd5\xa2\xa0\x9fR"\xa1\xa8' 

Just take that key and copy/paste it into your config file

SECRET_KEY = '\xfd{H\xe5<\x95\xf9\xe3\x96.5\xd1\x01O<!\xd5\xa2\xa0\x9fR"\xa1\xa8' 

See Sessions documentation

In order to use session in flask you need to set the secret key in your application settings. secret key is a random key used to encrypt your cookies and save send them to the browser.

This error is because of this line in the Flask-Debugtoolbar code

To fix this you just need to set a SECRET_KEY in your config file.

app.config['SECRET_KEY'] = "Your_secret_string" 

or if you have a config file just add below config to it:

SECRET_KEY = "Your_secret_string" 

Open Python, run following in you

import secrets secret_key = secrets.token_hex(16) # example output, secret_key = 000d88cd9d90036ebdd237eb6b0db000 app.config['SECRET_KEY'] = secret_key 

I recommend to hash it with bcrypt hash and use hex

# IMPORT from flask_bcrypt import Bcrypt import secrets secret_key = secrets.token_hex(16) #Create HEX Key bcrypt = Bcrypt(app) #Init Bcrypt secret_key_hash = bcrypt.generate_password_hash(secret_key) #hash the HEX key with Bcrypt app.config['SECRET_KEY'] = secret_key_hash #setup secret key # Output like: $2b$12$Y0QMIGwksa5OhtOBF9BczuAJ0hYMUv7esEBgMMdAuJ4V.7stwxT9e