Syntax

exchange.IO("base", ...)

Set the RPC node address of a Web3 exchange object; on EVM chains several nodes can back each other up.


    
    
    
exchange.IO(k)


    
    
    
exchange.IO(k, address)

Examples

Switch the RPC node to the BSC chain.


    javascript
    
    
function main() {
    var chainRpc = "https://bsc-dataseed.binance.org"
    exchange.IO("base", chainRpc)    // Switch to BSC chain
}

Set multiple nodes as backups for each other.


    javascript
    
    
function main() {
    // Multiple nodes as backups for each other: automatically switch to the next node when a node
    // is unavailable or rate-limited; nodes whose chainId is inconsistent with the first node will
    // not be used
    exchange.IO("base", ["https://bsc-dataseed.bnbchain.org", "https://bsc-rpc.publicnode.com"])
    Log("Node:", exchange.IO("base"))
    Log("Block height:", parseInt(exchange.IO("api", "eth", "eth_blockNumber"), 16))
}

Returns

Type	Description
string	When setting, returns the node address in use before the change (a comma-separated string for several nodes); without `address`, returns the current node address.

Arguments

Name	Type	Required	Description
k	string	Yes	Function of the `exchange.IO()` function. When set to `base`, it indicates that the function is used to switch RPC nodes.
address	string / array	No	Node address. Ethereum (EVM) accepts `http(s)://` and `ws(s)://` addresses; to set several nodes, pass an array of addresses or a string separated by commas (spaces or newlines also work). TRON only accepts a single full-node HTTP address, and passing several addresses (an array or a comma-separated string) is an error; the legacy gRPC addresses `grpc.trongrid.io:50051`, `grpc.nile.trongrid.io:50051` and `grpc.shasta.trongrid.io:50051` are mapped to the corresponding HTTP addresses, and any other non-HTTP address is an error. When omitted, only the current node address is queried.