I have used the following api for it. But I got error message saying: "error": { "message": "Calls to this api have exceeded the rate limit.", "type": "OAuthException", "code": 613, "error_subcode": 2791032, "is_transient": false, "error_user_title": "Rate Limit Time Window Expiry", "error_user_msg": "Notifications can only be sent to players who have played within 10 days. } API: POST /{recipient_userid}/notifications? access_token=...& href=...& template=You have people waiting to play with you, play now!