Adding Builder Codes

Integrate Base Builder Codes into an onchain application. Builder Codes append an ERC-8021 attribution suffix to transaction calldata so Base can attribute activity to your app and you can earn referral fees. No smart contract changes required.

When to Use This Skill

Use this skill when a developer asks to:

• "Add builder codes to my application"
• "How do I append a builder code to my transactions?"
• "I want to earn referral fees on Base transactions"
• "Integrate builder codes"
• Set up transaction attribution on Base

Prerequisites

• A Builder Code from base.dev > Settings > Builder Codes
• The ox library for generating ERC-8021 suffixes: npm install ox