These flows are actively being refined. Crossmint’s customer success engineers (CSE) will work with you to review your architecture. Contact Crossmint to get started.
The Problem
AI agents are increasingly performing long-running tasks on behalf of users: browsing the web, booking travel, managing subscriptions, purchasing supplies. But when these agents need to send or receive money, they hit a wall. They do not have access to payment credentials, and giving them raw card numbers or private keys is a security risk. Crossmint’s Agent Wallets solve this by giving each agent a modular financial identity: a combination of stablecoin wallets, virtual cards, and onramp capabilities, all controlled by the human user through secure delegation.Who Is This For
This guide is for developers building agent platforms, applications where AI agents perform tasks autonomously on behalf of users. Examples include:- Agent frameworks like OpenClaw
- Browser-based agent builders
- ChatGPT plugins, Claude tools, and similar integrations
- Custom agent platforms built on LangChain, CrewAI, or similar
How It Works
The solution is modular. You can adopt any combination of these capabilities, though they work best together:Stablecoin Wallet
Give your agent a non-custodial wallet that can hold USDC and make onchain payments, including x402.
Virtual Cards
Derive scoped virtual card numbers from the user’s existing card, with spend limits and human approval.
Card on File
Securely tokenize and store the user’s payment card in a PCI-compliant vault.
The Full Picture
When all modules are combined, the agent wallet becomes a unified financial interface:- The human user saves their card(s) on file through your app’s settings page.
- The agent can request delegated payment methods, either a virtual card (for card-based purchases) or a stablecoin top-up (for onchain payments and x402).
- The human reviews and approves each request through a consent UI.
- The agent can then pay autonomously, anywhere credit cards, stablecoins, or x402 are accepted.
Virtual cards are not new cards. They are tokenized representations of the user’s existing card, issued through Visa Intelligent Commerce and Mastercard Agent Pay. Charges appear on the user’s regular bank statement. The user keeps their points, dispute resolution rights, and everything else they are accustomed to.
Architecture Overview
Integration Paths
Choose the modules that match your agent’s needs:| Your agent needs to… | Modules required |
|---|---|
| Pay with credit cards at online checkouts | Card on File + Virtual Cards |
| Pay for APIs and services with stablecoins or x402 (funded via onramp from saved card) | Card on File + Stablecoin Wallet |
| Pay anywhere (cards, stablecoins, and x402) | All three modules |
| Hold and receive stablecoins only (no card) | Stablecoin Wallet only |
Reference Implementation
Crossmint has built a working reference implementation at lobster.cash, which demonstrates all of these flows working together in the context of OpenClaw agents. Use it as a blueprint for your own integration.Ready to get started? Crossmint’s customer success engineers (CSE) will work with you to review your architecture. Contact Crossmint to begin.