networks//RPC//CORS

Cross-Origin Resource Sharing (CORS) is the browser security mechanism that controls which web origins can call an RPC endpoint. On a node, `rpc-http-cors-origins=["*"]` allows any website at all to call it, which is convenient for development only.

Cross-Origin Resource Sharing (CORS) is the browser security mechanism that controls which web origins can call an RPC endpoint. On a node, rpc-http-cors-origins=["*"] allows any website at all to call it, which is convenient for development only.

The open setting becomes dangerous in production when the port is reachable from the internet, because any malicious page could then interact with the node. Any deployment beyond development restricts it to specific origins (["http://localhost:3000"]), one application of minimum privilege to an RPC node.