So I built a tool that you can give to your AI agent and with one API key it can call all of the services. The tool acts as a central auth and handles individual API's requirements like refreshing tokens, making sure rate limits are adhered, sends the correct user-agents and everything else that each API might require.
At first I wanted to provide all of the users no need to setup their own API keys, but that proved to be impossible. Most API providers state in their ToS that proxying the API is prohibited. Also there was the problem with identities: if an agent posts to Reddit or X the post is from the shared account. So I decided to add a bring-your-own-key architecture where you can setup your own keys (if you want to!) but the tool still handles all the token refreshing etc. Some generous services allow pretty lenient use of their API so I included those ready out of the box, no config required to getting started!
Right now I am happy using this tool myself but I wish more people used it so that I could work on improving it. Since I am a single dev there is a lot of work, I am adding new providers every day, fixing bugs and all that. But if anyone would give me their honest thoughts and tested the features I could work on improving the tool even more. There is an option to pay for the usage to cover some running costs but the free tier is more than enough to get building.