Table of Contents
Tokenization, PCI, and proxy cards: Solving payments for agentic commerce
Sophia Willows
Head of Engineering @ Rye
Aug 27, 2025
E-commerce agents shouldn't be touching raw card data. Rye uses tokenization and third-party PCI-compliant processors to enable safe, scalable universal agentic checkout.
If agentic commerce is going to work at scale, agents need a safe way to pay.
That’s a harder problem than it sounds. Raw credit card data is too sensitive to be handled casually and is especially dangerous to let pass through an LLM. At the same time, integrators using an API don’t want to touch that data either. Doing so would drag them into the heavy compliance world of PCI DSS, with all the security obligations that come with it. On top of all of the technical and compliance challenges, if consumers don’t trust AI to handle their sensitive data, they won’t feel comfortable making the purchase.
That’s why Rye designed Universal Checkout around tokenization, PCI compliance, and proxy cards. The goal: to allow agents to complete purchases on any e-commerce website while keeping credit card data safe.
If agentic commerce is going to work at scale, agents need a safe way to pay.
That’s a harder problem than it sounds. Raw credit card data is too sensitive to be handled casually and is especially dangerous to let pass through an LLM. At the same time, integrators using an API don’t want to touch that data either. Doing so would drag them into the heavy compliance world of PCI DSS, with all the security obligations that come with it. On top of all of the technical and compliance challenges, if consumers don’t trust AI to handle their sensitive data, they won’t feel comfortable making the purchase.
That’s why Rye designed Universal Checkout around tokenization, PCI compliance, and proxy cards. The goal: to allow agents to complete purchases on any e-commerce website while keeping credit card data safe.
If agentic commerce is going to work at scale, agents need a safe way to pay.
That’s a harder problem than it sounds. Raw credit card data is too sensitive to be handled casually and is especially dangerous to let pass through an LLM. At the same time, integrators using an API don’t want to touch that data either. Doing so would drag them into the heavy compliance world of PCI DSS, with all the security obligations that come with it. On top of all of the technical and compliance challenges, if consumers don’t trust AI to handle their sensitive data, they won’t feel comfortable making the purchase.
That’s why Rye designed Universal Checkout around tokenization, PCI compliance, and proxy cards. The goal: to allow agents to complete purchases on any e-commerce website while keeping credit card data safe.
Why raw card data can't flow freely
Systems that store or transmit cardholder data (CHD)—the card credit number (PAN), the CVV, and the expiration date—must meet strict requirements specified by PCI DSS to reduce the risks of theft and fraud.
Neither integrators nor models should ever see raw card data. For integrators, handling CHD directly means they take on PCI obligations themselves. In other words, by simply collecting, storing, and transmitting credit card data, they’d have to comply with a burdensome compliance regime that constrains their code, stack, and operational procedures. CHD has no place in an LLM, either: they aren’t secure vaults, and once a secret enters a model context it can’t be guaranteed to stay confined.
Tokenization
Tokenization allows credit card details to stay safe; it’s used in mobile wallets, and it’s also how Universal Checkout handles CHD. Developers start by generating a card token with a PCI-compliant payment provider like Stripe. This token is an opaque string representing the card details without exposing them. Because the integrator never handles the raw card number, its PCI obligations stay light, limited to the simplest self-assessment category.
This approach also opens the door to the next evolution of payments for agents: proxy cards from networks like Visa and Mastercard. These will enable single-use or merchant-specific credentials, further reducing risk for buyers and simplifying compliance for integrators.
Tokenization allows credit card details to stay safe; it’s used in mobile wallets, and it’s also how Universal Checkout handles CHD. Developers start by generating a card token with a PCI-compliant payment provider like Stripe. This token is an opaque string representing the card details without exposing them. Because the integrator never handles the raw card number, its PCI obligations stay light, limited to the simplest self-assessment category.
This approach also opens the door to the next evolution of payments for agents: proxy cards from networks like Visa and Mastercard. These will enable single-use or merchant-specific credentials, further reducing risk for buyers and simplifying compliance for integrators.
Tokenization allows credit card details to stay safe; it’s used in mobile wallets, and it’s also how Universal Checkout handles CHD. Developers start by generating a card token with a PCI-compliant payment provider like Stripe. This token is an opaque string representing the card details without exposing them. Because the integrator never handles the raw card number, its PCI obligations stay light, limited to the simplest self-assessment category.
This approach also opens the door to the next evolution of payments for agents: proxy cards from networks like Visa and Mastercard. These will enable single-use or merchant-specific credentials, further reducing risk for buyers and simplifying compliance for integrators.
Handling the token
Tokenization allows sensitive data to move safely, but a real payment still has to be made. Since Universal Checkout interacts with merchant websites, actual card details must be entered into a web form. Rye’s design keeps the data safe by ensuring that neither the integrator nor the LLM ever sees those details.
When the agent builds its plan, it works only with placeholders such as x_credit_card_number. It doesn’t know or handle the actual value. At runtime, Rye’s non-AI code retrieves the vaulted card details from the payment provider, enters them into the correct fields on the checkout form, and completes the order. Tokens are accepted only on confirmation endpoints, held only long enough to authorize the transaction, and never written to logs or metrics. (We hold other personal data required to complete transactions, like name and address, for a similarly fleeting period.)
The result is a clean separation: integrators operate at the API layer, agents at the planning layer, and only the secure, PCI-compliant path handles sensitive data. Payments are executed exactly as if the buyer entered their card on the merchant’s site, but without exposing secrets to anyone along the way.
Tokenization allows sensitive data to move safely, but a real payment still has to be made. Since Universal Checkout interacts with merchant websites, actual card details must be entered into a web form. Rye’s design keeps the data safe by ensuring that neither the integrator nor the LLM ever sees those details.
When the agent builds its plan, it works only with placeholders such as x_credit_card_number. It doesn’t know or handle the actual value. At runtime, Rye’s non-AI code retrieves the vaulted card details from the payment provider, enters them into the correct fields on the checkout form, and completes the order. Tokens are accepted only on confirmation endpoints, held only long enough to authorize the transaction, and never written to logs or metrics. (We hold other personal data required to complete transactions, like name and address, for a similarly fleeting period.)
The result is a clean separation: integrators operate at the API layer, agents at the planning layer, and only the secure, PCI-compliant path handles sensitive data. Payments are executed exactly as if the buyer entered their card on the merchant’s site, but without exposing secrets to anyone along the way.
Tokenization allows sensitive data to move safely, but a real payment still has to be made. Since Universal Checkout interacts with merchant websites, actual card details must be entered into a web form. Rye’s design keeps the data safe by ensuring that neither the integrator nor the LLM ever sees those details.
When the agent builds its plan, it works only with placeholders such as x_credit_card_number. It doesn’t know or handle the actual value. At runtime, Rye’s non-AI code retrieves the vaulted card details from the payment provider, enters them into the correct fields on the checkout form, and completes the order. Tokens are accepted only on confirmation endpoints, held only long enough to authorize the transaction, and never written to logs or metrics. (We hold other personal data required to complete transactions, like name and address, for a similarly fleeting period.)
The result is a clean separation: integrators operate at the API layer, agents at the planning layer, and only the secure, PCI-compliant path handles sensitive data. Payments are executed exactly as if the buyer entered their card on the merchant’s site, but without exposing secrets to anyone along the way.
Merchants stay the merchant of record
Because transactions are completed directly with the merchant, the integrator has no role in the transaction. With the sole exception of Amazon, where Rye is the merchant of record (MoR), every merchant remains the MoR. This is important: not being MoR means integrators can avoid complicated and costly procedures like sales tax accounts, customer service, refunds, and liability for chargebacks. In other words, merchants keep the customer relationship, and integrators don’t accidentally become e-commerce retailers.
Because transactions are completed directly with the merchant, the integrator has no role in the transaction. With the sole exception of Amazon, where Rye is the merchant of record (MoR), every merchant remains the MoR. This is important: not being MoR means integrators can avoid complicated and costly procedures like sales tax accounts, customer service, refunds, and liability for chargebacks. In other words, merchants keep the customer relationship, and integrators don’t accidentally become e-commerce retailers.
Because transactions are completed directly with the merchant, the integrator has no role in the transaction. With the sole exception of Amazon, where Rye is the merchant of record (MoR), every merchant remains the MoR. This is important: not being MoR means integrators can avoid complicated and costly procedures like sales tax accounts, customer service, refunds, and liability for chargebacks. In other words, merchants keep the customer relationship, and integrators don’t accidentally become e-commerce retailers.
Learn more
Payments are one of the hardest parts of agentic commerce to get right. Rye has built a process that’s safe, compliant, and ready for production, without obligating the integrator to take on compliance or contractual obligations.
Check out the docs and see how to integrate universal checkout with tokenized payments into your AI experience.
Payments are one of the hardest parts of agentic commerce to get right. Rye has built a process that’s safe, compliant, and ready for production, without obligating the integrator to take on compliance or contractual obligations.
Check out the docs and see how to integrate universal checkout with tokenized payments into your AI experience.
Payments are one of the hardest parts of agentic commerce to get right. Rye has built a process that’s safe, compliant, and ready for production, without obligating the integrator to take on compliance or contractual obligations.
Check out the docs and see how to integrate universal checkout with tokenized payments into your AI experience.
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