I’m going to work on API which will be as conversion between different format as XML to JSON or JSON to XML. But I don’t need how I can write SRS for such conversion api.

I need to call a function which will get JSON as input and will give XML as output so only three requirement to list in SRS?

1. There should be JSON data
2. Call the Method (But I don’t think so it will be listed because I’m developing API not using it)
3. You will get output in XML (Even this also not required?)

For more, let suppose I have a module which convert the Json to XML. So which functional requirement requires for this module?

There I’m only expecting three requirement as I listed above.

Same process for other conversion. Now I totally don’t know how I can write SRS for such simple API project.