Delegation and EOAs

EIP-7702 allows existing EOAs to temporarily adopt Brain's programmable behavior without migrating to a new address, making onboarding seamless for users with existing wallets.

What EIP-7702 Enables

EIP-7702 allows externally owned accounts to delegate their transaction validation to smart-contract logic. The delegation is visible on-chain and is always revocable by the EOA owner. Brain provides validator contracts compatible with this standard.

Use Cases

• Onboarding without migration — users keep their existing addresses

• Session-based delegation — agents act on behalf of a user for a defined period

• Temporary agent authority — auto-expiring delegation with revocation support

Delegation Flow

1

User signs a delegation authorization

The message specifies Brain's validator contract address and any constraints (time limits, spend caps).

2

EOA attaches the Brain validator

Per EIP-7702, the Brain validator contract becomes the execution logic for that EOA address.

3

Policy engine co-validates

All transactions from the EOA pass through Brain's policy engine and validator contract before executing.

4

Revocation

When delegation is revoked or expires, the EOA immediately reverts to standard behavior. No migration needed.

Constraints

EIP-7702-based delegation in Brain is always bounded by:

• Time limits — delegation can be set to auto-expire

• Revocability — the EOA owner can revoke at any time, on-chain

• Brain policy enforcement — all delegated execution still passes through the policy engine

Constrained delegation is a core security guarantee. No EIP-7702 delegation can bypass Brain's policy engine or exceed the user's configured constraints.

Comparison: EOA Delegation vs. Smart Account

	EOA + EIP-7702	Brain Smart Account
Address migration required	No	Yes (new account address)
Policy enforcement	✓	✓
Agent authorization	✓	✓
Native ERC-4337 features	Limited	Full
Recommended for	Existing wallet users onboarding	New users and production agents