MEV-Share and Order Flow Auctions

MEV-Share is Flashbots' next-generation transaction submission protocol. Instead of broadcasting your transaction publicly (where searchers frontrun) or fully privately (where no MEV rebate is possible), MEV-Share selectively reveals parts of your transaction to searchers in exchange for a rebate.

How it works

1. User submits transaction to MEV-Share.
2. MEV-Share partially reveals it (e.g., token pair but not amount) to searchers.
3. Searchers submit backruns (arbitrage that would profit from user's tx).
4. User's transaction is bundled with the winning backrun.
5. User receives a percentage of the MEV extracted from their tx (typically 90%).

Why this matters

• Public mempool: user gets zero of the MEV, searcher takes 100%.
• Fully private: user gets zero (no MEV opportunity, no rebate).
• MEV-Share: user gets 90%, searcher gets 10%.

Order Flow Auctions (OFA)

The broader category. Wallets and dApps route user transactions to auctions where searchers bid for the right to execute. Best bid wins; user captures most of the value.

Major OFA implementations

• MEV-Share (Flashbots). Trusted, backrun-focused.
• CoW Protocol. Batch auction, solvers compete.
• 1inch Fusion. Similar solver competition.
• UniswapX. Uniswap Labs' intent-based auction.

What users get

• Rebates on MEV that would otherwise leak to searchers.
• Sandwich protection.
• Better prices via solver competition.

What wallets get

• New revenue stream: wallets can capture part of the OFA revenue by routing user tx through partnered auction.
• MetaMask, Rainbow, and others integrating.