EIP-3085 primary sources — 2026-05-09

Project status in this pass

• No standalone EIP-3085 whitepaper or litepaper surfaced.
• The strongest source of truth was the canonical EIP, with MetaMask documentation useful for confirming live wallet implementation patterns.
• The sources consistently frame EIP-3085 as a wallet-controlled chain-registration and metadata-validation interface.

Primary-source snapshots

1) Canonical EIP page

• URL: https://eips.ethereum.org/EIPS/eip-3085
• Key excerpt/signals:
  • The abstract says the EIP adds a wallet-namespaced RPC method, wallet_addEthereumChain, for adding chains to Ethereum wallets.
  • The page is marked Stagnant, which matters because the method is still influential in practice despite not advancing through the EIP process.
  • The rationale says the design is deliberately ignorant of what it means to “add” a chain, because that remains a wallet implementation detail.
• Why it mattered:
  • This is the clearest source-level evidence that EIP-3085 is not a chain registry itself; it standardizes the request boundary between dapp and wallet.

2) Raw EIP text / request shape and validation

• URL: https://raw.githubusercontent.com/ethereum/EIPs/master/EIPS/eip-3085.md
• Key excerpt/signals:
  • The parameter object includes chainId, optional explorer/icon/name/currency metadata, and rpcUrls.
  • The wallet MUST reject missing or empty rpcUrls, invalid URLs, and URLs whose eth_chainId response does not match the requested chainId.
  • The wallet MUST reject invalid nativeCurrency fields, invalid explorer URLs, invalid icon URLs, and any http: or file: URLs.
• Why it mattered:
  • These rules show that EIP-3085 is really about validation and trust boundaries, not just about making a network appear in a wallet picker.

3) Raw EIP text / wallet authority and separation from switching

• URL: https://raw.githubusercontent.com/ethereum/EIPs/master/EIPS/eip-3085.md
• Key excerpt/signals:
  • Only chainId is formally required, but wallets MAY require additional fields, ignore requester-supplied fields, or prefer their own metadata.
  • The EIP says a successful add MUST NOT be assumed to automatically select that chain.
  • The wallet MUST NOT allow the same chainId to be added multiple times.
• Why it mattered:
  • This is the strongest evidence that EIP-3085 governs wallet chain-registry state, while active-chain routing remains a separate control surface.

4) Raw EIP text / security and privacy framing

• URL: https://raw.githubusercontent.com/ethereum/EIPs/master/EIPS/eip-3085.md
• Key excerpt/signals:
  • The security section says wallets should never use a chain ID returned by an RPC endpoint for signing.
  • It also says wallets should clearly inform users which RPC URL is in use and the risks of unknown endpoints and multiple endpoints.
  • The privacy section warns that automatically succeeding when a chain is already added leaks information about the wallet’s configured networks.
• Why it mattered:
  • This reveals where authority and risk actually sit: endpoint trust, wallet validation policy, and the information a wallet chooses to reveal about supported chains.

5) MetaMask network-management docs

• URL: https://docs.metamask.io/metamask-connect/evm/guides/manage-networks/
• Key excerpt/signals:
  • The docs say MetaMask Connect EVM supports both wallet_switchEthereumChain and wallet_addEthereumChain for network management.
  • They show a switchChain helper that accepts an optional chainConfiguration object so unknown chains can be added during the same switching flow.
  • The examples include chain name, native currency, RPC URLs, and block explorer URLs in a modern integration path.
• Why it mattered:
  • This is good live evidence that EIP-3085 remains operational ecosystem plumbing, even if consumer integrations often encounter it through higher-level SDK helpers instead of raw RPC calls.

6) MetaMask raw JSON-RPC example page

• URL: https://docs.metamask.io/metamask-connect/evm/reference/json-rpc-api/wallet_addEthereumChain/
• Key excerpt/signals:
  • The docs provide a direct provider.request({ method: 'wallet_addEthereumChain', ... }) example.
  • The example includes chain metadata fields matching the EIP’s parameter model.
• Why it mattered:
  • This confirms that the EIP’s request shape remains the live integration surface exposed to dapps.

Working conclusion

EIP-3085 is best cataloged as wallet chain-registration control-plane infrastructure. The decisive evidence in this pass was its strict RPC and metadata validation rules, explicit separation from active-chain switching, endpoint-trust security model, and continuing practical use in MetaMask’s live network-management flow.