It is an API. You can implement all this stuff from scratch with raw requests library in python if you want. Its the idea of a standard around information interchange, specifically geared around agentic experiences like claude code, (tools like aider, previously, that are much worse) - its like a FastAPI web app framework around building stuff that can helps LLMs and VLMs and model wrapped software in ways that can speak over the network.

Basically like Rails-for-Skynet

I'm building this: https://github.com/arthurcolle/fortitude