I want to make a system for sending, receiving and swapping cryptocurrencies. So, I need to set up a wallet on AWS Linux server which supports most coins and provides an API to connect to. It should allow sending coins and providing addresses.
What should I do for this?
Cryptocurrency wallets, by definition, should not use API as they are self-custodial. This mean that only you as an owner can initiate the transfer of assets. Having an API service for a cryptocurrency wallet is unsafe, because the sysadmin of the API service can steal your funds.
I'd recommend you use a command line tool or a programmable library like Web3.js Web3.py for wallet management.
That being said, there are commercial custody service providers like BitGo that provide cryptocurrency wallets with API.