What Is FAST RPC?
FAST RPC is a drop-in Ethereum RPC endpoint that routes transactions through the mev-commit preconfirmation network for sub-second confirmations and mev protection.
FAST RPC is a drop-in Ethereum RPC endpoint. Add it to your wallet, and every transaction you send routes through the mev-commit preconfirmation network instead of the public mempool.
No new wallet. No new interface. No new workflows. The same eth_sendTransaction you've always used — with sub-second confirmations and mev protection.
What an RPC does
Every Ethereum wallet needs an RPC (Remote Procedure Call) endpoint to communicate with the network. When you send a transaction, your wallet sends it to an RPC provider, which broadcasts it to the Ethereum network. Common RPC providers include Infura, Alchemy, and the default endpoints bundled with wallets.
Standard RPCs broadcast your transaction to the public mempool — a waiting area where anyone can see pending transactions. Searchers monitor the mempool to extract mev from your transactions before they're included in a block.
How FAST RPC is different
FAST RPC accepts the same JSON-RPC calls as any standard Ethereum endpoint, but routes transactions through a completely different path:
- Your transaction reaches FAST RPC via standard
eth_sendTransaction - FAST RPC routes it to the mev-commit network — bypassing the public mempool entirely
- Block builders compete for the right to include your transaction in an open auction
- The winning builder issues a preconfirmation — a cryptographic commitment to include your transaction at a specific position
- You receive confirmation in ~200ms
- The transaction settles on-chain in the next Ethereum block, exactly as committed
Your transaction never enters the public mempool. Searchers can't see it, can't frontrun it, and can't sandwich it.
Adding FAST RPC to your wallet
FAST RPC works with any Ethereum wallet that supports custom RPC endpoints:
- MetaMask: Fast Protocol can add the network automatically — click "Add RPC to Wallet" in the app menu
- Rabby and other wallets: Add the FAST RPC URL as a custom Ethereum network
Once added, you can toggle between standard Ethereum RPC and FAST RPC depending on whether you want preconfirmation-backed execution.
What you get
Sub-second confirmations: Every transaction sent through FAST RPC receives a preconfirmation in ~200ms. You know your transaction will be included before the block is produced.
mev protection: Transactions bypass the public mempool, eliminating exposure to sandwich attacks and frontrunning.
mev redistribution: The builder auction returns at least 90% of generated mev to you as improved execution.
Same wallet, same tools: FAST RPC is a standard JSON-RPC endpoint. No migration, no learning curve, no new keys.
Beyond swaps
While Fast Protocol's swap interface is the primary way users interact with preconfirmations today, FAST RPC works for any Ethereum transaction. Contract interactions, NFT mints, DeFi operations — any transaction that would benefit from faster confirmation and mev protection can route through FAST RPC.
The RPC endpoint is the infrastructure layer. The swap interface is one application built on top of it.
Frequently Asked Questions
- What is FAST RPC?
- FAST RPC is an Ethereum-compatible RPC endpoint that routes your transactions through the mev-commit preconfirmation network instead of the public mempool. It provides sub-second confirmations and mev protection without requiring any changes to your wallet or tools.
- Is FAST RPC compatible with my wallet?
- Yes. FAST RPC is a standard Ethereum JSON-RPC endpoint. It works with MetaMask, Rabby, and any other Ethereum wallet that allows adding a custom RPC endpoint. You use your existing wallet — just point it at the FAST RPC URL.
- Does FAST RPC protect against mev?
- Yes. Transactions sent through FAST RPC bypass the public mempool entirely. They route through a private channel to the mev-commit builder auction, where builders compete for your order flow. This prevents sandwich attacks and ensures at least 90% of generated mev is returned to you.