Flashblocks API Quickstart

Get started building on Base using Flashblocks

Introduction

Flashblocks on Base are a transaction preconfirmation feature that provides near-instant transaction feedback by streaming partial block updates every 200 milliseconds. This significantly reduces the effective block time from Base’s standard 2 seconds to just 200 milliseconds, a 10x increase.

Flashblocks is great for developers who demand instant UX such as decentralized exchanges, onchain gaming, and other high-frequency applications.

Getting started instructions

Flashblocks is currently supported on both Base testnet and mainnet and can be accessed using your existing Alchemy Base RPC or websocket endpoint.

NetworkFlashblocks Availability
Base Sepolia
Base Mainnet

Flashblocks-enabled API Endpoints