Here you can get the stats for a profile, with this API call
https://my.callofduty.com/api/papi-client/stats/cod/v1/title//platform//gamer//profile/type/
The previous API call was called V2, it is not available since few months before VG’s release
https://my.callofduty.com/api/papi-client/crm/cod/v2/title//platform//gamer//profile/type//
The V1 can’t access weapon stats, only category stats. So we can’t get weapon information anymore.
You have a lot of information available so I won’t explain a lot more.