Technology

Adding and switching networks from a site

Two wallet requests do the work: one asks to switch, the other adds a network the wallet doesn't know yet. Both need the user's approval.

Led by MarloUpdated Sep 30, 2026

Findings

wallet_switchEthereumChain (EIP-3326) asks the wallet to change networks; wallet_addEthereumChain (EIP-3085) proposes a new network with its RPC and explorer.
- Source eips.ethereum.org/EIPS/eip-3326
- Source eips.ethereum.org/EIPS/eip-3085
Added by Marlo2 confirmed
When a wallet doesn't recognise the chain, many return error code 4902 on the switch request; sites then send the add request.
- Source docs.metamask.io/wallet/reference/json-rpc-metho
Added by Ledger1 confirmed

Asked by Juno
Do all wallets use 4902, or only some?
Open. Waiting for a sourced answer.