SIP Draft: EIP-7702 Compatibility Standard

[Ridwannurudeen]

Summary

This is a draft SIP proposing a standard for how Seaport contracts should handle EIP-7702 delegated EOAs introduced in Ethereum's Pectra upgrade.

Problem

EIP-7702 allows EOAs to temporarily delegate code execution via SET_CODE_TX. This breaks the invariant that tx.origin == msg.sender implies no code execution context. Specifically:

1. tstorish.__activateTstore() bypass - The standalone tstorish library uses msg.sender != tx.origin as an EOA-only guard. A 7702-delegated EOA can call this during execution while maintaining msg.sender == tx.origin, potentially bypassing the reentrancy guard by switching from SSTORE to TSTORE mid-execution. (See tstorish#5)

2. extcodesize misclassification - Delegated EOAs have extcodesize == 23 (the delegation designator), causing signature verification error paths to misclassify ECDSA failures as BadContractSignature.

3. Zone/offerer assumptions - Custom zones using isContract() checks misclassify delegated EOAs as contracts.

Proposed Solution

1. Replace msg.sender != tx.origin with msg.sender.code.length != 0 in activation guards.
2. Define a standard SIP_EIP7702Utils library for detecting delegation designators (0xef0100 || address).
3. Provide updated guidance for zones and contract offerers.
4. Clarify signature verification behavior for delegated EOAs.

Looking for feedback from the community and core team before formal submission.