Receiving "Access Denied" for most API calls
I have a custom Service and am attempting to make REST API calls to retrieve activities. In doing so, I am getting nothing but "Access Denied" errors such as:
{"requestId":<...>,"success":false,"errors":[{"code":"603","message":"Access denied"}]}
Some background:
My API user is an Admin. I have checked and double checked that the Admin role has all permissions available


Prior to making an API call, I generate a bearer token using the `/identity/oauth/token?grant_type=client_credentials` endpoint.
I have tried the following endpoints and receive the Access Denied error for each call attempt:
- /rest/v1/activities/pagingtoken.json
- /rest/v1/lists.json
- /rest/v1/leads/...
- /rest/v1/leads/describe.json
The one Endpoint which reliable succeeds is `/rest/v1/stats/errors.json`:
{"requestId":<...>,"result":[{"date":"2016-02-26","total":1,"errors":[{"errorCode":"603","count":1}]}],"success":true}
Are there other permissions that allow my API user to access the specified endpoints? Is there something I'm missing?
Thanks!
Message was edited by: Zack Schultz (Added note about connecting via the identity endpoint first)