Tag Archives: API

Python OAuth2 auth and bearer token caching

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To access many APIs you need to use OAuth2, sending a client id and secret to an endpoint to get a token back. Then send that token with future calls as authentication.

The particular API I was calling would also return a number of seconds the bearer token would be good for.

Hopefully this code will help jumpstart someone else along the way to using python and APIs.

#!/usr/bin/env python3

import requests
import json
import datetime

import os.path
from os import path

cache_file = "/var/tmp/oauth.json"
client_id = '**your client_id here**'
client_secret = '**your secret here**'

def getToken():
    url = "https://api.wherever.com/oauth2/token"

    data = {
      'client_id': client_id,
      'client_secret': client_secret,
      'grant_type': 'client_credentials'
    }

    response = requests.post(url, data=data)

    data = json.loads(response.text)
    expiration_time =  datetime.datetime.now() +  datetime.timedelta(seconds=data['expires_in'])
    data['expiration_date'] =   int(expiration_time.utcnow().timestamp())

    with open(cache_file, "w") as outfile:
        json.dump(data, outfile)
    return data



if path.exists(cache_file):
    #Reading cache
    with open(cache_file, "r") as infile:
        access_token = json.load(infile)
    if int(datetime.datetime.now().timestamp()) > access_token['expiration_date']:
        #Token expired, get new
        access_token = getToken()
else:
    #No cached value, get and cache
    access_token = getToken()


bearer_token = access_token["access_token"]
headers = {
        'Authorization': f'bearer {bearer_token}'
}

#The rest of the requests go here and pass that header

4/24/2023: updated to fix typo!