Scalable Stablecoin Payments for Shopify: How Coinbase Payments Uses CDP Wallets to Unlock USDC on Base
June 19, 2025
By Yuga Cohler Fabrice Cheng Dan Kim
TL;DR: To make USDC payments feel native to Shopify’s checkout, Coinbase Developer Platform built a solution that abstracts blockchain complexity – wallets, gas, key management – while supporting secure authorization, refundability, and real-time transaction visibility. The result meets Shopify’s high standards for compliance, performance, and UX – at a global scale.
A Global USDC Checkout, Without Blockchain Friction
When Shopify set out to support USDC in its checkout, the goal was clear: enable fast, global, programmable payments—without the blockchain friction. That meant no wallets to manage, no gas fees to explain, and no added complexity in the user experience. The solution had to meet high standards for operational control, compliance, and performance – all while preserving Web2-grade UX.
To meet these requirements, and to do so at Shopify’s global scale, Coinbase partnered with Shopify to launch a production-grade USDC checkout on Base, Coinbase’s Ethereum Layer 2. And part of the integration runs on Coinbase Developer Platform infrastructure; specifically, CDP Wallets, which power the checkout flow through two key components: the Smart Wallet API and CDP Paymaster
These tools abstract away the complexity of wallets, keys, and gas fees using ERC-4337-based architecture, including Bundlers and Paymasters. Coinbase’s open-source Smart Wallet and developer-first APIs bring this abstraction to life—making programmable, gasless wallets work seamlessly for modern enterprises like Shopify.
Why E-Commerce Needs Better Payments
Legacy payment systems create unnecessary friction for modern merchants. High fees eat into margins, settlement delays slow down access to revenue, and geographic limitations restrict global reach.
USDC presents a modern alternative: it’s price-stable and fully backed 1:1 by USD, offers instant finality through onchain settlement, and provides global accessibility with low transaction costs.
CDP enabled Shopify to integrate USDC natively – without compromising on UX, security, or platform extensibility. The result was a transaction model that mirrors Web2 performance and control, but with onchain rails and programmable execution.
How the Integration Worked
At the core of the Shopify integration is CDP Wallets' Smart Wallet API, which Coinbase uses to create a new Smart Wallet for each Operator. These Smart Wallets are ERC-4337-compatible accounts that support programmable transaction logic without requiring end users to manage keys, wallets, or gas.
CDP Wallets supports flexible key management. In this integration, we brought our own signing keys and maintained full control over wallet operations. CDP’s infrastructure handled the rest – wallet creation, transaction execution, policy enforcement, and gas abstraction – through composable APIs.
The integration included:
Smart Wallet API – used to programmatically create Smart Wallets for each Operator and sign transactions; also stores lightweight buyer profiles to simplify repeat purchases
Paymaster – sponsors transaction fees on Base, removing blockchain friction and ensuring that buyers never need to hold ETH or manage gas
Together, these components allowed us to deliver secure, gasless, policy-aligned payment flows – while maintaining direct control over signing logic.
“Our goal was to bring the benefits of USDC – speed, global reach, programmability – into Shopify checkout without exposing merchants or buyers to blockchain complexity. Coinbase’s Smart Wallet API and Paymaster gave us exactly that: a powerful abstraction layer that lets us integrate onchain payments while preserving the reliability, control, and UX that Shopify is known for.” – Nick Chen, Senior Product Lead at Shopify
Implementation Summary
To support Shopify’s global checkout needs, we used CDP Wallets' Smart Wallet API to provision a Smart Wallet for each Operator. These wallets, compliant with ERC-4337, enabled us to retain full signing control using our own keys, while relying on CDP for transaction assembly, simulation, and submission.
Key integration components included:
Operator Wallets – created via Smart Wallet API, supporting programmable transaction flows and buyer profile reuse
Custom Signing – we brought our own signing keys, maintaining full control over wallet operations
Gas Sponsorship – CDP Paymaster covered all gas fees on Base, removing the need for ETH balances or frontend gas logic
Streamlined UX – wallet operations and gas handling were fully abstracted, preserving Shopify’s high UX standards
CDP’s Smart Wallet infrastructure provided critical operational guarantees:
Nonce management and fee sequencing via CDP’s Bundler – ensuring transaction reliability at Shopify scale
Built-in gas management – eliminating the need for custom relayers or error handling logic
Transaction simulation – failed operations are caught before submission, improving system resilience
KYT enforcement – supports compliance with transaction screening requirements
This architecture let us meet Shopify’s performance, compliance, and operational goals – without building and maintaining our own bundler, relayer, or policy enforcement layer.
What Developers Can Learn
General Development Tips
Smart Wallet API supports both custom and CDP-managed signing keys, giving teams flexibility around custody and control
Paymaster abstracts gas, simplifying frontend engineering and enabling gasless flows
CDP APIs are composable – adopt wallet creation, transaction signing, policy enforcement, or monitoring independently
Transaction simulation and KYT enforcement are built into the Smart Wallet backend – invalid or risky transactions are blocked before submission
“CDP’s tools allowed us to abstract blockchain complexity while retaining control. This enabled us to build a gasless, programmable checkout aligned with merchant expectations.” – Aleksandar Savic, Senior Software Engineer at Coinbase
Error Handling and Fallbacks
Pre-fund Paymaster to ensure uninterrupted sponsorship
Handle 401 Unauthorized errors by checking API key scopes and X-Wallet-Auth headers
Handle 409 Conflict (nonce mismatch) by fetching the latest nonce before re-signing
Paymaster Best Practices
Use policy controls to limit which transactions are eligible for sponsorship (by address, amount, or contract)
Log all sponsored transactions for observability and support
Design fallback paths for when Paymaster is unavailable (e.g., user-pays-gas mode)
Build with CDP Tools
The Coinbase Developer Platform gives teams the infrastructure to launch secure, scalable, and programmable onchain payment systems. For this integration, Coinbase used: Smart Wallet API – to programmatically create ERC-4337-compatible Smart Wallets, control signing workflows, and enforce transaction policies — all while retaining ownership of private keys, and Paymaster – to abstract gas and sponsor transaction fees on Base, enabling a gasless checkout experience for end users
Explore more from CDP Wallets
Server Wallets – API wallets with keys secured by CDP in a Trusted Execution Environment (TEE)
Embedded Wallets – Coming soon: native, app-level wallets for end-user control and seamless onchain interactions
Explore the Docs
Interested in building with CDP Wallets? Talk to our team
