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Sending Tx and Bundles

Flashbots provides a variety of methods for submitting transactions and bundles. This guide is designed to help you understand these options and select the one that best fits your needs.

Understanding Relay and RPC Endpoints

Flashbots offers two primary JSON-RPC endpoints on Ethereum Mainnet: and - For Retail Users

  • Purpose: Designed specifically for retail users as a drop-in RPC replacement in their wallet.
  • Features: Provides MEV protection and MEV refunds for eligible transactions. Support all the regular Ethereum JSON RPC methods but not Flashbots specific JSON RPC methods.
  • Performance: Rate limited to satisfy the need of regular users.
  • Note: Transactions are submitted through eth_sendRawTransaction to fit wallet RPC interface. Underneath, the endpoint uses to submit transactions. - For Advanced Users

  • Purpose: Designed for advanced users, including searchers, applications, and Telegram bots. It accepts both transactions and bundles.
  • Features: Support all Flashbots specific JSON RPC methods. Does not support regular Ethereum JSON RPC methods.
  • Performance: Offers a high rate limit of 10,000 requests per second per IP address.
  • Recommendation: Ideal for activities beyond simple transaction submissions via wallets.

Choosing the Right JSON-RPC Method

With identified as the go-to for advanced operations, the choice of JSON-RPC methods is as follows:

  • For Single Transactions: Use eth_sendPrivateTransaction.
  • For Bundles of Transactions: