Our APIs use Oauth 2.0 Protocol for authentication and authorization. Once the app is authenticated our servers return back the access token and refresh token which are valid for 1 hour and 1 week respectively. You are able to cache the tokens and use them to request new access/refresh tokens after they are expire. We provide different authorization flows for a client application :

• Authorization Code Flow ( recommended for Client/Browser Applications )
• Resource Owner Password Credentials Flow (ROPC)
• Refresh Token Flow

More information on Authorization Flows could be found here : https://developer.ringcentral.com/api-docs/latest/index.html#!#AuthorizationFlows.html

---

Thanks for share.This link may everyone know.It is better if you share the parameter,you passed in api to get the refresh token.

---

The parameter for refresh_token is almost same as grant_type password with minor change.

url will be same: https://platform.devtest.ringcentral.com/restapi/oauth/token

Headers:

"Accept":"application/json“

"Content-Type":"application/x-www-form-urlencoded“

"Authorization",:"Basic <ClientID:ClientSecret in base 64> 

Body:

In body, we need to pass the parameters in following way :

username=<account phone number>&password=<account password>&extension=<your extension>&grant_type=refresh_token&refresh_token=<the refresh token generated>

---