# Flashbots Auction Relay (JSON-RPC)

**Canonical:** https://apis.io/apis/flashbots/auction-relay/  
**Provider:** Flashbots — https://apis.io/providers/flashbots/  
**Base URL:** https://relay.flashbots.net  
**Documentation:** https://docs.flashbots.net/flashbots-auction/advanced/rpc-endpoint

Flashbots Auction Relay (JSON-RPC) is one of 7 APIs that [Flashbots](https://apis.io/providers/flashbots/) publishes on the [APIs.io](https://apis.io/) network. Tagged areas include JSON-RPC, Bundles, Private Transactions, Auction, and Ethereum. The published artifact set on APIs.io includes API documentation and authentication docs.

JSON-RPC endpoint for submitting bundles and private transactions to the Flashbots block builder. Supports eth_sendBundle, eth_callBundle, eth_cancelBundle, eth_sendPrivateTransaction, eth_cancelPrivateTransaction, mev_sendBundle, mev_simBundle, and fee refund methods. Requests are authenticated with an X-Flashbots-Signature header (EIP-191).

## Machine-readable artifacts (4)

- **Documentation** — https://docs.flashbots.net/flashbots-auction/advanced/rpc-endpoint
- **Authentication** — https://docs.flashbots.net/flashbots-auction/advanced/rpc-endpoint#authentication
- **Repository** — https://github.com/flashbots/rpc-endpoint
- **APIsJSON** — https://raw.githubusercontent.com/api-evangelist/flashbots/refs/heads/main/apis.yml

## Other Flashbots APIs (6)

- [Flashbots Auction Relay (Sepolia Testnet)](https://apis.io/apis/flashbots/auction-relay-sepolia/)
- [Flashbots Protect RPC](https://apis.io/apis/flashbots/protect-rpc/)
- [MEV-Share Node API](https://apis.io/apis/flashbots/mev-share-node/)
- [MEV-Boost Relay](https://apis.io/apis/flashbots/mev-boost-relay/)
- [SUAVE](https://apis.io/apis/flashbots/suave/)
- [Flashbots Flashbots Auction & MEV Share Relay (JSON RPC) API](https://apis.io/apis/flashbots/flashbots-flashbots-auction-mev-share-relay-json-rpc-api/)

## Tags

JSON-RPC, Bundles, Private Transactions, Auction, Ethereum

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/flashbots/auction-relay/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/flashbots/.