PrimeV

# Primev Documentation > Complete technical documentation for mev-commit, Fast Protocol, FAST RPC, and Fastx402 — Ethereum infrastructure for preconfirmations, instant swaps, and agentic payments. Primev builds core infrastructure for Ethereum's mev supply chain. The mev-commit protocol enables peer-to-peer preconfirmation commitments between bidders and block builders, providing sub-second transaction guarantees on Ethereum mainnet. ## Products - [FAST RPC](https://docs.primev.xyz/v1.2.x/developers/fast-rpc-api): Drop-in Ethereum JSON-RPC replacement at `https://fastrpc.mev-commit.xyz`. Transactions sent through FAST RPC receive binding preconfirmation commitments from block builders. Supports all standard `eth_` methods plus custom `mevcommit_` methods. - [Fast Protocol](https://docs.primev.xyz/v1.2.x/concepts/fast-protocol): Order flow auction (OFA) on top of mev-commit. Users receive at least 90% of mev their transactions generate. Redistributed as Fast Miles (tokenizable points). - [Fast Swaps](https://docs.primev.xyz/v1.2.x/concepts/fast-swaps): Token swap interface on Ethereum mainnet. Gasless ERC-20 swaps via EIP-712 signed intents through Permit2. Supports 2,400+ tokens. Settlement via FastSettlement V3 contract on L1. - [Fastx402](https://docs.primev.xyz/v1.2.x/developers/fastx402): x402 payment facilitator for AI agents. USDC payments via EIP-3009 `transferWithAuthorization`. Sub-second settlement through FAST RPC. Zero fees. Endpoint: `https://facilitator.primev.xyz`. ## FAST RPC API Endpoint: `https://fastrpc.mev-commit.xyz` Standard Ethereum JSON-RPC methods are supported. Key overridden methods: - `eth_sendRawTransaction` — Sources preconfirmations on mev-commit chain. Transaction is enqueued privately (not sent to public mempool). Returns transaction hash. - `eth_getTransactionReceipt` — Returns receipt early if enough preconfirmations obtained for mev-commit opted-in slots. Block hash set to tx hash for preconfirmed transactions. - `eth_getTransactionCount` — Returns mempool count + queued transactions in private pool. - `eth_maxPriorityFeePerGas` — Always returns 0 (priority fee should be 0 for FAST RPC users). - `eth_getBlockByHash` — For preconfirmed tx hashes, returns a fictitious block containing only that transaction. Additional FAST RPC methods: - `mevcommit_getTransactionCommitments` — Takes tx hash, returns array of commitments received on mev-commit network (provider addresses, signatures, decay timestamps). - `mevcommit_getBalance` — Takes account address, returns available deposit balance for that address. - `mevcommit_optInBlock` — Returns time in seconds until the next block with a mev-commit opted-in validator. - `mevcommit_cancelTransaction` — Takes tx hash, cancels commitment attempts. No cost. - `mevcommit_estimateDeposit` — Returns estimated deposit cost and EOA wallet address for funding. - `mevcommit_estimateBridge` — Returns estimated bridging cost and destination address for instant L1-to-mev-commit-chain bridging. ## Fastx402 API Endpoint: `https://facilitator.primev.xyz` - `GET /supported` — Returns supported payment kinds, extensions, and signer addresses. Response: `{"kinds":[{"x402Version":2,"scheme":"exact","network":"eip155:1"}],"extensions":["bazaar"],"signers":{"eip155:*":["0x488d87a9A88a6A878B3E7cf0bEece8984af9518D"]}}` - `POST /settle` — Verify and settle a USDC payment on-chain via FAST RPC. Body: `{"paymentPayload":{"x402Version":2,"scheme":"exact","network":"eip155:1","payload":{"signature":"0x...","authorization":{"from":"0x...","to":"0x...","value":"1000000","validAfter":"0","validBefore":"...","nonce":"0x..."}}},"paymentRequirements":{"scheme":"exact","network":"eip155:1","amount":"1000000","asset":"0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","payTo":"0x...","maxTimeoutSeconds":60}}` - `POST /verify` — Validate a payment signature without settling (dry run). Same body as /settle. - `GET /health` — Health check. USDC contract: `0xA0b86991c6218b36c1d19D4a2e9E […gekürzt]