How to Build a Token-Gated Discount System in 20 Lines of Code

You have a storefront. Your most loyal customers hold your project's token. You want to give them a discount automatically. No coupon codes, no manual lists, no spreadsheet of wallet addresses. Here is how to wire that up with a single API and about 20 lines of Express.js. What we are building A lightweight Express server that: Takes a customer's wallet address Checks whether they hold a specific token on any of 31 supported chains Returns the discount they qualify for The API doing the heavy lifting is InsumerAPI . It handles the multi-chain lookup and returns a simple boolean: does this wallet meet the condition, yes or no? It never exposes raw balances to your server. Every response is signed with ECDSA P-256, so you can verify the result cryptographically. Step 0: Grab a free API key No credit card, no OAuth. One POST request: curl -X POST \ https://us-central1-insumer-merchant.cloudfunctions.net/createDeveloperApiKey \ -H "Content-Type: application/json" \ -d '{"email": "you@examp