Its’s neither obvious from your post nor your GitHub landing page, which is a shame.
The other question I would have is: who is the target audience, and why are API calls specifically so important?
> The calculation algorithm is provided by Sustainable Web Design
And links to: https://sustainablewebdesign.org/calculating-digital-emissio...
> NOTE: This page is regularly updated to include the most recent research and information.
Also, the same page:
> Last update: April 17, 2022.
Call me naive but I was hoping research in this area will be faster/more frequent, given also the Cop27.
> Carbon factor (global grid): 442 g/kWh
Probably just checking how many bytes the response is. While that's a good idea to remove unused data from your response, this test may promote wrong patterns such as spreading data over multiple request/response. This would consume more energy but won't be visible with a naive CO2 computation.
Streaming is dumb, cacheable near end-users and heavy in bandwidth. API uses little bandwidth but often requires calls to multiple remote backend systems heavy in CPU, including subrequests to databases and other stuff. When you mix all usage and get an average KPI, it's no longer representative.