(Python) Refresh a Dynamics CRM OAuth2 Access Token

Demonstrates how to refresh an expiring Dynamics CRM access token using the refresh token. endpoint.

(If a REST API call fails with a 401 unauthorized error, an application can auto-recover by refreshing the access token, and then re-send the request using the new token.)

Chilkat Python Downloads install with pip pip3 install chilkat or download... Python Module for Windows, MacOS, Linux, Alpine Linux, Solaris

import sys
import chilkat

#  This example requires the Chilkat API to have been previously unlocked.
#  See Global Unlock Sample for sample code.

#  We previously obtained an access token and saved the JSON to a file using this example:
#  Get Dynamics CRM OAuth2 Access Token

#  This example will examine the JSON and expiration date, and if near expiration will
#  refresh the access token.

json = chilkat.CkJsonObject()
success = json.LoadFile("qa_data/tokens/dynamicsCrm.json")
if (success != True):
    sys.exit()

#  The contents of the JSON look like this:
#  {
#    "token_type": "Bearer",
#    "scope": "user_impersonation",
#    "expires_in": "3599",
#    "ext_expires_in": "0",
#    "expires_on": "1524783438",
#    "not_before": "1524779538",
#    "resource": "https://mydomain.api.crm.dynamics.com",
#    "access_token": "...",
#    "refresh_token": "...",
#    "id_token": "..."
#  }

#  The "expires_on" value is a Unix time.
dtExpire = chilkat.CkDateTime()
dtExpire.SetFromUnixTime(False,json.IntOf("expires_on"))

#  If this date/time expires within 10 minutes of the current system time, refresh the token.

#  OK, we need to refresh the access token by sending a POST...
# 

req = chilkat.CkHttpRequest()
req.AddParam("grant_type","refresh_token")
req.AddParam("redirect_uri","http://localhost:3017/")
req.AddParam("client_id","DYNAMICS-CRM-CLIENT-ID")
req.AddParam("client_secret","DYNAMICS-CRM-SECRET-KEY")
req.AddParam("refresh_token",json.stringOf("refresh_token"))
req.AddParam("resource","https://mydynamicsdomain.api.crm.dynamics.com")

http = chilkat.CkHttp()

# resp is a CkHttpResponse
resp = http.PostUrlEncoded("https://login.microsoftonline.com/DYNAMICS-ENDPOINT-GUID/oauth2/token",req)
if (http.get_LastMethodSuccess() != True):
    print(http.lastErrorText())
    sys.exit()

#  Load the JSON response.
json.Load(resp.bodyStr())
json.put_EmitCompact(False)

#  Show the JSON response.
print(json.emit())

print("Response status code: " + str(resp.get_StatusCode()))

#  If the response status code is not 200, then it's an error.
if (resp.get_StatusCode() != 200):
    sys.exit()

#  If an "expires_on" member does not exist, then add the JSON member by
#  getting the current system date/time and adding the "expires_in" seconds.
#  This way we'll know when the token expires.
if (json.HasMember("expires_on") != True):
    dtExpire.SetFromCurrentSystemTime()
    dtExpire.AddSeconds(json.IntOf("expires_in"))
    json.AppendString("expires_on",dtExpire.getAsUnixTimeStr(False))

#  Save the refreshed access token JSON to a file for future requests.
fac = chilkat.CkFileAccess()
fac.WriteEntireTextFile("qa_data/tokens/dynamicsCrm.json",json.emit(),"utf-8",False)