Here is what I wanna do: I want to create some sort of a bridge connection between my chatting App and other messaging services like WhatsApp for my users to be able to chat from my App to WhatsApp and vice-versa.
So I've been trying to implement it, and I've noticed that even though some of their APIs are public but they're fairly limited and I can't directly access them to say (create a bot), the only option I have is to create the bots manually(I want it to be programmatic) and then copy the access token to interact with the bots and listen for messages(which are only for business accounts and not for actual users), so I came across Matrix and was kind of dumbfounded that they provide real-time bridging from several messaging services with their own clients(e.g. https://Element.io), I've been searching for a long time and I couldn't find an answer for this.
How does Matrix bridge these messaging services if their public APIs are so limited?