As AI continues to reshape financial infrastructure, Stripe-backed Tempo is introducing a new payments protocol designed to enable intelligent, programmable transactions at scale.
Tempo, a payments-focused blockchain backed by Stripe and crypto investment firm Paradigm, launched its mainnet on March 18, bringing its stablecoin payment system out of testing and into live use after roughly three and a half months in a test phase.
Even more significant part of the launch is the startup’s announcement of the MPP solution. Tempo’s open standard for machine payments is called the Machine Payments Protocol (MPP) and is co-authored by Stripe and Tempo. It provides a standard way for agents and services to coordinate payments programmatically, enabling machine payments to work across services and payment rails. It currently works with stablecoins, cards, and other supported payment methods.
Similar agent payment protocol initiatives of different scale have been earlier introduced by industry giants such as PayPal, Google, Visa, and Stripe itself. In the blockchain-based settings, two emerging standards: x402 and ERC‑8004 are gaining attention as the foundation for the next era of digital economic activity driven by AI and agent interactions.
The notable feature of the new MPP protocol is that it introduces a new primitive called “sessions” — essentially OAuth for money. An agent authorizes a spending cap once, then streams micropayments continuously as it consumes services like data, compute, or API calls.
Some of the tech stack controversies of the new protocol were highlighted by Donald Gossen, Founder & CEO of Nevermined, who “got early access to the specification”. In his LinkedIn post, the tech entrepreneur explains that in this system, the merchant (server) is responsible for decrypting payment data sent by the buyer (client/agent), but the merchant doesn’t control what kind of card data it receives (e.g. safer DPAN (tokenized card number) or real PAN card number), which is unusual, since normally, sensitive card data is kept away from merchants.
In such a scenario, Gossen continues, all merchants must follow strict PCI compliance rules (security standards for handling card data), which can be expensive and complex. Another potential issue, in his opinion, is that MPP doesn’t connect all transactions into one shared system (global ledger), while “for agent-to-agent payments to scale, imo having a global ledger that all agents are able to plug into is the optimal approach,” says Gossen.
Nevertheless, this open standard has already been enhanced by early launch partners, including Visa, which extended MPP to support card-based payments, and Lightspark, which did so for Bitcoin payments on the Lightning Network.
The launch comes as global payments firms increasingly see blockchain rails and stablecoins as key infrastructure for cross-border finances, simultaneously acknowledging the growing imperative of supporting user-authorised automatic transactions conducted by semi-autonomous AI agents.
The news article was updated on March 19, 2026, with comments on the tech aspects of the protocol by Donald Gossen.
