The [IPC (Inter-Process Communication)](https://en.wikipedia.org/wiki/Inter-process_communication) transport allows our program to communicate with a node over a local [Unix domain socket](https://en.wikipedia.org/wiki/Unix_domain_socket) or [Windows named pipe](https://learn.microsoft.com/en-us/windows/win32/ipc/named-pipes).
Using the IPC transport allows the ethers library to send JSON-RPC requests to the Ethereum client and receive responses, without the need for a network connection or HTTP server. This can be useful for interacting with a local Ethereum node that is running on the same network. Using IPC [is faster than RPC](https://github.com/0xKitsune/geth-ipc-rpc-bench), however you will need to have a local node that you can connect to.
In this example, we monitor the [`WETH/USDC`](https://etherscan.io/address/0xb4e16d0168e52d35cacd2c6185b44281ec28c9dc) [UniswapV2](https://docs.uniswap.org/) pair reserves and print when they have changed.