x402 on Catena: Dollar Accounts, Controls, and Evidence
Catena supports x402 natively with customer-defined controls: agents pay for services straight from dollar accounts, within policy and spending limits, and every payment lands as a first-class ledger transaction with linked evidence.
AI agents increasingly need to buy things to do their jobs: API access, datasets, compute, browser sessions, and specialized research. However, these payments look different from traditional business purchases. They tend to be task-oriented, pay-per-use, and made at machine volume. Accordingly, a handful of new payment protocols have been developed to serve this burgeoning agent activity.
One of these protocols is x402.
When we added native x402 support to our banking platform, we focused on applying customer-defined controls and existing business processes around its use. As a result, we have unlocked something of real value for the early customers on our platform: the opportunity to leverage paid, agent-driven tasks safely at scale.
Customer-controlled authority
With standalone, bare-bones agent payments, signing authority for the transactions typically sits quite close to the agent runtime. That can increase the potential impact of prompt injection, compromised dependencies, or other hostile inputs reaching the process.
On Catena, an agent always first authenticates before submitting a payment intent. The intent is evaluated against customer-defined policies, spending limits, approved providers, and approval requirements. The signing architecture is designed so that neither the agent nor Catena can move customer funds alone. Catena enforces the customer’s instructions; it does not replace the customer as the source of financial authority.
We previously wrote about moving policy enforcement into the signing layer itself, and x402 has been an excellent demonstration of how this multi-layered approach enables agent operators to use payment protocols, such as x402, with bounded authority, layered controls, and a clear record of what happened.
Flexible dollar accounts
Many agent payment protocols, including x402, leverage stablecoins as a faster, programmatic way of exchanging value. However, not all businesses have ready access to these stablecoins. Setting up accounts with the relevant providers can be difficult, leaving companies running payments out of two separate places.
Catena lets businesses pay for x402 services straight from their dollar accounts. If a service settles in a supported stablecoin, Catena handles the conversion with the customer’s authorization, and the payment runs through the same policy, approval, signing, and evidence controls as any other transaction. That means a business does not need to become operationally stablecoin-native before its agents can access services offered through agentic payment protocols.
Evidence beyond settlement
A settlement response can show that a payment occurred, but businesses also need the surrounding operational context: which agent initiated it, what the customer authorized, which policy was evaluated, whether human approval was required, and how the result appears in the business’s records.
Catena preserves that context around all paid-tool commerce. The agent proposes an action; policy evaluates it; the action is approved, held for human review, or blocked; an approved action executes and settles; and the policy, approval, settlement, and evidence context remain linked afterward.
Every payment is a first-class ledger transaction, including the $0.001 ones, with the original 402 challenge preserved alongside it. Operators can review linked evidence, inspect activity across supported payment methods, export reports, and investigate or disposition operational exceptions without rewriting the underlying transaction history.
Autonomy within clear limits
A diligence agent might purchase a company-registry lookup, a KYB report, and selected records from an approved data provider. A coding agent might pay for a test environment, browser session, evaluation run, or GPU job.
At machine volume, the answer is not to approve every small payment manually. The business needs to be able to pre-authorize routine purchases within explicit provider, amount, and velocity limits, while unusual amounts or unapproved providers are held for human review.
Agent payments can offer enormous advantages over traditional payment rails, but only when used within a clear and reliable policy system. Our approach to x402 reflects our approach to agent payment protocols more generally, including Machine Payments Protocol or Mastercard’s Agent Pay for Machines: as one of many options to be leveraged within a durable and consistent financial product.
Catena is currently in private access. Join the waitlist to explore governed agent commerce (including x402 workflows) with test funds in a secure sandbox and move to production when your policies are fully tested.
