Session Keys And Delegation
Local signing, permissions, and EIP-7702 in smart wallets.
Session keys and delegation allow smart accounts to temporarily authorize actions without exposing the main wallet key. These patterns unlock new UX for games, dApps, and mobile wallets — though they are not yet standardized and are implemented wallet-by-wallet.
🔐 What Are Session Keys?
Session keys are ephemeral keypairs that:
Are authorized by the smart account
Have a defined scope (methods, dApps, gas limit)
Can be revoked or time-limited
They allow:
Local signing in dApps
Multiplatform delegation
Non-interactive usage (e.g., scheduled jobs)
🛂 Delegation Models
Static Delegation
Grant a key ongoing permission to act on the account
Must be explicitly revoked
Dynamic Delegation
Sign a session token with constraints (e.g.,
validUntil,targetContract)Enforced in
validateUserOp()by wallet-specific logic (e.g., a plugin or auth module); not natively supported by ERC-4337
🪄 EIP-7702: Temporary Smart Wallet Mode for EOAs
EIP-7702 lets EOAs temporarily delegate control to smart contract logic for a single transaction.
Uses the same address as the EOA
Includes a
contractCodeandvalidationDataRestores to an EOA after execution
This supports passkeys, session UX, and smart extensions without permanent migration to a smart wallet.
ethereum.org recommends submitting 7702-based txs through the UserOperation mempool to preserve censorship resistance:
“Consider using the UserOperation mempool for relaying smart EOA transactions to avoid base-layer censorship.” Read more →
⚙️ Implementation Notes
Many ERC-4337 wallets use signature aggregation modules
Session key delegation can be done via plugin (ERC-6900/7579)
Tokens or NFTs can act as auth factors (e.g., token gating)
✅ Summary
Session keys and delegation expand smart account usability across devices and flows. With EIP-7702, even EOAs gain the ability to temporarily act like smart wallets — enabling powerful hybrid UX that balances flexibility, security, and compatibility.
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