EIP-3326

  • Name: EIP-3326 (Wallet Switch Ethereum Chain RPC Method / wallet_switchEthereumChain)
  • URL: https://eips.ethereum.org/EIPS/eip-3326
  • Category: Ethereum wallet chain-switch standard / active-chain routing control surface / network-context handoff interface
  • Tags: ethereum-ecosystem
  • Summary: EIP-3326 is best understood as active-chain routing infrastructure rather than as a small UX helper for network pickers. Its core move is to let dapps request that a wallet change which chain it treats as active, while keeping approval and state-transition handling inside the wallet. The mechanism significance is that EIP-3326 formalizes a narrow but powerful boundary: the dapp can ask for a chain context switch, but the wallet decides whether the chain is known, whether the request is safe, and how pending requests and confirmations are invalidated when the active network changes.
  • What it does:
    • Defines wallet_switchEthereumChain, an RPC method for asking a wallet to switch its active chain
    • Uses a minimal object parameter containing only a hexadecimal chainId
    • Requires the requested chain to already be known to the wallet and serviceable by it
    • Returns null on success and an error otherwise
    • Applies only to wallets that actually have a concept of one active chain at a time
    • Recommends wallet confirmations and cancellation of pending chain-specific requests when switching occurs
  • Key claims:
    • The abstract says the method allows dapps to request that the wallet switch its active Ethereum chain, which is the clearest reason to treat EIP-3326 as a routing/control-plane standard rather than a wallet-brand feature
    • The specification defines the active chain as the one the wallet is forwarding RPC requests to, which makes this a request about execution context, not just a UI preference toggle
    • The chain ID MUST be a hexadecimal eth_chainId value, MUST be known to the wallet, and the wallet MUST be able to switch to it and service RPC requests there, so the standard assumes registry authority remains with the wallet rather than the requesting dapp
    • The rationale explicitly contrasts EIP-3326 with EIP-3085 and EIP-2015, saying it intentionally omits metadata because it is purely about switching active chain context, regardless of endpoint or chain metadata management
    • The security section says wallets should always display a confirmation and should cancel pending RPC requests and chain-specific user confirmations when a switch occurs, which is analytically important because it acknowledges that chain switching re-frames outstanding user actions
    • The privacy section warns that auto-rejecting unknown chains leaks support information about the wallet, so even refusal behavior becomes part of the wallet’s information surface
    • MetaMask’s current docs expose both the raw wallet_switchEthereumChain request and a higher-level switchChain helper, which is strong evidence that the stagnant EIP still governs real wallet-dapp network switching flows in practice
  • Whitepaper: No standalone EIP-3326 whitepaper or litepaper surfaced in this pass. The clearest materials were the canonical EIP, the raw spec text, and current MetaMask network-management documentation gathered in ../../whitepapers/eip-3326-primary-sources-2026-05-09.md.
  • Sources:

Internal linkages

  • Chain-registration sibling that usually precedes switching when the target network is not yet known: eip-3085
  • Provider baseline that actually exposes the active-chain state and chainChanged event to apps: eip-1193
  • Last reviewed: 2026-06-02 UTC