The Ethereum protocol runs on various testing networks ("testnet"), allowing developers to test their applications before deploying code on the main network ("mainnet"). Ropsten is one of those testing networks.
The USDC smart contract has been deployed to the Ropsten testnet and is available on address 0x07865c6e87b9f70255377e024ace6630c1eaa37f.
As Ropsten is a testing network, the USDC tokens in circulation there are minted in a completely arbitrary way, and are in no way backed by real US dollars.
Circle's sandbox environment is connected to USDC on the Ropsten testnet.
In other words, when you send funds from a Circle hosted wallet to an external blockchain address, it will be send as USDC on Ropsten. Similarly, if you want to receive funds from an external blockchain address, you can use USDC on Ropsten to achieve that.
Updated 3 months ago