How to get user's custom networks

[qiduo]

Hi, community, just as the title said, i want to retrieve all user’s customized networks and display different page depends on user’s networks. Is there any API or method? Or should it be a feature which may be added in the future?

[Tksly]

How to Add Custom Networks To MetaMask like Binance and Polygon (MATIC)

A user asks: How do I add custom networks like Binance Smart Chain, Polygon or Avalanche to MetaMask?** How to Add Custom Networks To MetaMask by CryptoHamilton This is an excellent question because many users are not aware of different custom networks with lower gas fees or how to set them up on MetaMask. Some incorrectly think that MetaMask sets the high fees and tries to rip them off. In reality, it’s market demand for a blockchain network that sets the prices. MetaMask has no control ove…

[qiduo]

Sorry for the misunderstand. What I mean is I want to retrieve the networks in user’s MetaMask via some MetaMask API or methods, so that I can show the correct answer to the user. Or let’s say I want to know whether the User’s MetaMask is added a custom network or not, which api or method(such as eth_chainId) I should use in Javascript.

[nakedwinnie]

Is this so you can prompt the user to switch to the correct network?

What do you need the user’s custom networks for?

[qiduo]

Yes, exactly.

I want to get all users’ custom network to filter the network that he did not added, or I can guide him/her to add some networks if he/she haven’t added any other networks except the default network, i.e ethereum mainnet.

[nakedwinnie]

wallet_addEthereumChain and wallet_switchEthereumChain is likely what you are looking for.

Here is more information on the MetaMask docs:

RPC API | MetaMask Docs

[qiduo]

Thanks a lot, i’ve just went my deadends, using wallet_addEthereumChain and wallet_switchEthereumChain is the what exactly what I want.