# singer-tap-development


11/09/2022, 9:09 PM
Hi all, I am new to meltano tap development, so i apologize if this solution was provided in a documentation. I am working on a tap which pulls a list of values from one api and then i want to use each those values (one-by-one) to call another API so that i fetch it in a stream to load it in the database. I think the language in meltano SDK states its called an external API lookup(as mentioned below in screenshot), could you please confirm if the above functionality is called an external API lookup? if so, then is there a sample code i lookup to see how to “implement a custom Mapper plugin with inline lookup logic ” which was stated in the documentation or some reading where i can learn more on how to develop that functionality for my tap. If i a misunderstood the description- could you point me to the right resource where i can learn more about how to develop this functionality? Thanks a ton for all your help in advance.