EIP-7793 introduces the ASSERTTXINDEX opcode (0xfb), which reverts a transaction unless it is executed at a specific index within a block. This is designed to support encrypted mempools by preventing reordering of decrypted transactions, effectively mitigating frontrunning risks. The opcode ensures static validation by requiring the expected index to be read from calldata at the start of execution. It has a fixed gas cost of 3.

EIP-7843 introduces the SLOTNUM opcode (0x4b), allowing smart contracts to directly access the current slot number of a block. This removes the need to compute it from timestamps or include it as calldata, both of which are inefficient or error-prone. The slot number is calculated in the consensus layer and exposed at low gas cost (2), enabling more robust and future-proof smart contract design.

📄 EIP Reference
EIP-7793: https://eips.ethereum.org/EIPS/eip-7793
EIP-7843: https://eips.ethereum.org/EIPS/eip-7843
Discussion Threads:
EIP-7843: https://ethereum-magicians.org/t/eip-7843-slotnum-opcode/22234
EIP-7793: https://ethereum-magicians.org/t/eip-7793-asserttxindex-opcode/21513

🎬 Related Content
Presentation: View Slides

💸 Support Ethereum Cat Herders
Donate: https://www.ethcatherders.com/donate

👥 Featuring
Guest Speaker: Marc Harvey-Hill
Ethereum Cat Herders Team:
Host: Pooja Ranjan
Coordinator: Vaelyn
Editor: Akash

🕒 Timestamps
00:00 - Quick Recap
00:37 - PEEPanEIP Intro
00:51 - Introduction
01:23 - About EIPs
02:17 - Marc Introduction
03:24 - Presentation on EIP-7793 & 7843
03:34 - The Ethereum Roadmap
04:10 - EIP-7843 - SLOTNUM opcode
05:26 - EIP-7793 - ASSERTTXINDEX opcode
06:00 - Motivation
12:18 - Last Slide
12:26 - Presentation End
12:39 - Is the bundler a new system contract?
13:37 - Use cases of these EIPs
14:22 - What is EIP-7843 and what problem does it solve?
17:09 - How easy is it to use EIP-7793?
18:48 - Is this EIP targeted for Fusaka upgrade?
20:21 - Community and client feedback
21:54 - Security and Risk
22:55 - EIPs deployment
23:56 - Client Feedback
24:54 - Marc's experience proposing the EIPs
26:25 - Rapid Fire Round
29:45 - Closing Words

🔗 Follow Ethereum Cat Herders
X/Twitter: https://twitter.com/ethcatherders
Farcaster: https://warpcast.com/ethcatherders
Medium: https://medium.com/ethereum-cat-herders
Discord: https://discord.gg/H2eYpKCxxm

#EIP7793 #EIP7843 #Ethereum #PEEPanEIP #eip