100Pay Launches pay402: A Next-Generation Payment Protocol That Lets AI Agents Pay — and Get Paid
Now powering multiple products across the 100Pay ecosystem, pay402 extends the HTTP 402 standard with multi-currency support, zero-setup infrastructure, and automatic API discovery for the emerging agentic economy
Today we announced a major update to pay402, our payment protocol designed for the age of autonomous AI agents. First released in December 2025, pay402 has seen rapid adoption since launch — attracting a growing community of developers and powering real-world integrations across the 100Pay product ecosystem. Built on top of the widely adopted HTTP 402 standard, pay402 goes further than existing implementations by removing infrastructure barriers, supporting a broad range of payment currencies, and enabling developers to automatically monetize their APIs to AI agents — without writing a single line of extra configuration code.
As AI agents move from answering questions to taking actions — booking services, querying data, and executing multi-step workflows — the internet's payment infrastructure has struggled to keep up. Traditional systems require human intervention. Even newer machine-native protocols demand dedicated backend infrastructure that creates friction for smaller developers. pay402 was built to close that gap, and the traction it has gained in just a few months signals that the market has been waiting for exactly this.
How pay402 Works — and What Makes It Different
The HTTP 402 "Payment Required" status code has been part of the web specification since the early 1990s, reserved for a future where micropayments would be native to the internet. Protocols like x402 have finally begun realising that vision by allowing AI agents to autonomously pay for API access using stablecoins over standard HTTP requests.
pay402 extends this standard while solving three persistent challenges that have limited adoption:
No facilitator server required. Existing x402 implementations require developers to set up and maintain a facilitator — a dedicated verification middleware that settles on-chain transactions. pay402 eliminates this entirely. Developers can integrate the protocol in minutes, with 100Pay's infrastructure handling payment verification and settlement transparently in the background.
Multi-currency pricing and settlement. Where x402 primarily settles in USDC on blockchain networks, pay402 supports a flexible range of payment options — including fiat currencies settled directly to a merchant's bank account. This bridges the gap between Web3-native developers and mainstream businesses who need local currency payouts without managing crypto wallets. pay402 also natively supports PAY, the utility token powering the paytoken.cash ecosystem, giving developers access to a growing base of token holders seeking to put their assets to work.
Automatic API discovery for AI agents. One of pay402's most distinctive features is its ability to automatically expose a developer's API routes to AI agents across the network. When a developer deploys a service using pay402, it is discoverable by AI agents looking for tools to use — creating a two-sided marketplace where developers build once and earn continuously, without manual promotion or registration.
Already Powering the 100Pay Ecosystem
Since its December 2025 debut, pay402 has moved well beyond a developer preview. The protocol has been integrated into several live products within the 100Pay ecosystem, demonstrating the real-world viability of agent-native commerce.
A flagship example is NanoChat (nanochat.io), an AI assistant built to help users get anything done online. NanoChat uses pay402 to complete purchases on pay402-enabled servers autonomously — no checkout forms, no redirects, no manual confirmation required. When a user asks NanoChat to acquire a paid resource or service, the assistant handles the entire transaction in the background using the protocol, making it one of the clearest demonstrations to date of what frictionless agentic commerce looks like in practice.
The adoption of pay402 across multiple products within the 100Pay ecosystem reflects a broader design philosophy: the protocol is not just infrastructure for third-party developers, but a foundational layer that 100Pay itself builds on. As the ecosystem grows, pay402 becomes more valuable — every new pay402-enabled server is discoverable by every agent already using the network.
Designed for the Agentic Economy
The rise of autonomous agents — software that acts independently on behalf of users and businesses — represents a fundamental shift in how digital services are consumed. Agents don't sign up for subscriptions. They don't enter credit card details. They need to transact programmatically, at speed, at scale, often for amounts too small for traditional payment rails to handle economically.
pay402 makes this possible. An AI agent encountering a pay402-protected endpoint receives structured payment instructions in the HTTP response, pays automatically using its configured wallet or payment method, and retries the request with cryptographic proof of payment — all in under a few seconds, with no human in the loop.
For developers, this means a new revenue stream that requires minimal integration. For businesses, it means machine-readable APIs that can be consumed by the rapidly expanding universe of AI-powered tools and agents. For the broader internet, it means a payment layer as native and frictionless as the web itself.
Availability
pay402 is available today at 402.finance. Developers can integrate the protocol using the pay402 SDK and begin accepting payments from both human users and AI agents immediately. Documentation, quickstart guides, and API references are available on the platform.
About 100Pay
100Pay is a fintech infrastructure company building payment primitives for the next generation of the internet. With pay402, 100Pay bridges the gap between traditional financial systems and the emerging agentic economy — making it possible for any developer to monetize their work, in any currency, for any client, human or machine.
Website: https://402.finance
Contact: [email protected]
Forward-looking statements in this release are based on current expectations and are subject to change. PAY token and cryptocurrency features involve inherent risks. This release does not constitute financial or investment advice.
