Passing a Custom field in API

question customer calls on my virtual number from exotel and exotel lets me know via callback that i have indeed received a call from this number for this i am using miss called plus app however, i was wondering if its possible for me to pass some custom fields per mobile number which you can then send it back to me as part of the callback in passthru applet unfortunately, it is not possible to pass along your own parameter for incoming calls but in most cases, we have found that it is possible to maintain the necessary custom variables & their values at your end because the from & to number is unique for a phone call ( you can also include a timestamp if needed or use the callsid field that you get in the pings ), you could persist the custom values at your end and load them as soon as you get the ping from exotel passing a custom variable is possible for outbound calls via api see the customfield parameter in our call connect api we have listed all our apis here https //developer exotel com/api#call