CapitalOne DEVEXCHANGE Messtone LLC Operations POST /credit-cards/credit-offers/prescreen-applications POST /credit-cards/credit-offers/acknowledge-prescreened-application:The Capital One DevExchange Sandbox(https://api-sandbox.capitalone.com)is a virtual testing environment that simulates the way each API will respond in a production environment.It provides a secure and isolated space where Messtone can test his application code with touching any real Capital One accounts or Userrharper@messtone.com data.When Messtone finished testing,get ready to go live by requesting production access.Generate access token Messtone Operation curl -i –tlsv1.2 -X POST{ENVIROMENT_HOSTMESSTONE}/oauth2/token -d client_id=MESSTONE_CLIENT_ID -d client_secret=MESSTONE_CLIENT_SECRET -d grant_type=client_credentials {ENVIRONMENT_HOSTMESSTONE}/oauth2/authorize?client_id=MESSTONE_CLIENT_ID&redirect_uri=MESSTONE_REDIRECT_ URI&scope=APPROPRIATE_SCOPE&response_type=code&state=MESSTONE_STATE_VALUE Messtone app’s configured Redirect URI and displayed in the browser’s address bar:https://www.redirecturi.com/?code=yH_GuChI9toMzIASBbFLh-PyIWWqLOVDg040og Refresh token Refresh API call: curl -i –tlsv1.2 -H “Accept: application/json ” -H “Content-Type: application/x-www-form-urlencoded” -d client_id=MESSTONE_CLIENT_ID” -d “refresh_token=REFRESH_TOKEN_FROM_ACCESS_TOKEN_RESPONSE” -X POST {ENVIRONMENT_HOSTMESSTONE}/oauth2/token Response HTTP/1.1 200 OK {“access_token”:”TMjU2IiwicGNrIjoxLCJhbGciOiJ…”,”token_type”:”Bearer”,”expires_in”:900,”refresh_token”:”c47JrxxRWEu12yvl79yi-o0UEb3C2rXC…”}