Very often the first thing I do, after creating the project with mix new, is to write a README.md and explain what the library is, common usage and configuration. I find it to be a good exercise before getting on with the actual implementation.

Looks like “Readme Driven Development” is already a term:

http://tom.preston-werner.com/2010/08/23/readme-driven-development.html

You’re on a good path. Have a look at ex_aws - it’s doing basically the same thing, i.e. wraps HTTP API.

The tough part might be to decide which config options go into config and which ones you want to pass around. One thing that makes many libraries useless for me is when I build a multi-tenant app and the library wants me to put the API key into the config, whereas I need to make an API call with different API keys.

In regards to configuration for your library, I really like what @michalmuskala lays out in this article: http://michal.muskala.eu/2017/07/30/configuring-elixir-libraries.html

@stefanchrobot Thank you for recommending ex_aws I will definitely look there as my starting point. I also have faced similar problems in multi tenant app. Will have to think wisely about the configuration parts.

@svilen Thank you for recommending about “Readme Driven Development”. Will look there also. Cause I will opensource this library. I think it is good to do the README from day one

@axelson Thank you for recommending, the article about the configuration. Will be looking there also.

Another good resource is the Elixir Library Guidelines, specifically the section on avoiding application configuration.