Fee Efficiency

On EVM-enabled chains, users often overpay on priority fees due to first-price auction dynamics. While EIP-1559 introduced a predictable, algorithmic base fee, the maxPriorityFee (tip) users attach to get their transaction included still follows a first-price model, meaning users pay whatever they bid, even if a lower tip would’ve worked. Codex eliminates this inefficiency at the sequencer level, reducing execution costs for everyone.

Codex converts every EIP-1559-style auction into a second-price sale for the priority fee. Users still post the maximum tip they are willing to pay, but are only charged the clearing tip (the second-highest bid), so any unused priority fee never leaves their wallet.

• Second Price Auction: The Codex sequencer itself reorders EIP-1559 transactions by maxPriorityFee, sets the clearing tip to the second highest bid at block build time, and caps every transaction’s effective tip at that value.
• Automatic Refunds: Because only the clearing tip is ever debited, any excess priority fee is retained in the sender’s balance, no separate refund transaction or contract call is required.