well, there is an existing request for a GET /photos endpoint: https://forum.inaturalist.org/t/photo-detail-endpoint-for-api/40481. you can add your support for it there if you haven’t already. or since you have some coding aptitude, you could do what the other person in the thread i referenced earlier did and just add the functionality you’re looking for. you can see exactly what changes they made and start from there.