Metamask: How to Change RPC URL Programatically
As of my last update in April 2023, the official MetaMask API documentation doesn’t directly allow changing the rpcUrl parameter programmatically. However, it does offer a few ways to achieve this, which may not be as straightforward or efficient as expected but are still workable under certain conditions.
Method 1: Using the Web3.js library and its eth_accounts method
You can use the Web3.js library to get the current accounts from MetaMask’s RPC URL. Then, you can compare these with your desired RPC URL. Here is a simplified example:
async function changeRpcUrl() {
try {
// Get the current account (should be '0x...')
const currentAccount = await Web3.eth.getAccounts();
// Your desired RPC URL
const newRpcUrl = '
// Check if the account is '0x...' and compare with your RPC URL
if (currentAccount[0] === '0x...') {
console.log('Account matches new RPC URL');
// Update the Web3 instance or network configuration to use the new RPC URL
} else {
console.log('Account does not match new RPC URL');
}
} catch (error) {
console.error(error);
}
}
changeRpcUrl();
Please note that changing your web3 instance directly might require manual adjustments of the network configuration.
Method 2: Using the MetaMask API’s own endpoint to change the rpcUrl
The official MetaMask API has a method called setRpcUrl which you can use, but like the Web3.js example above, it requires manual updating of your account’s RPC URL through this method. However, be aware that there is no direct way to update this through the MetaMask browser UI as you might expect.
Here is how to do it:
async function changeRpcUrl() {
try {
// Get the current account (should be '0x...')
const currentAccount = await Web3.eth.getAccounts();
// Your desired RPC URL
const newRpcUrl = '
// Set the rpcUrl parameter programmatically
await provider.setRpcUrl(newRpcUrl, {
// Additional parameters could be set here if needed (e.g., chainId)
});
} catch (error) {
console.error(error);
}
}
changeRpcUrl();
Note on web3 and Network Configuration
It’s recommended to handle the network configuration manually rather than relying on the provided methods, as changes can propagate through multiple chains or networks.
Always keep your web3 instance up-to-date before updating any RPC URLs.