The internet was designed without a native payment layer, creating decades of friction. Yet, a hidden piece of infrastructure has been waiting for its moment: the HTTP 402 “Payment Required” status code.
The architects of the original web specification decades ago were forward-thinking, reserving the 402 status code in anticipation of a future need for native payment standards. That future has come, rolled out by Coinbase.
X402 has arrived: the on-chain payment gateway for AI and APIs. This revolutionary protocol finally activates the sleeping giant, turning that long-unused code into a powerful engine for instantaneous, blockchain-based micropayments across the web.
It’s so great that FLock.io couldn’t resist adopting it. We are creating a unified gateway for on-chain Agents to pay for the brains (AI Models) that drive them with X402.
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What exactly is X402?
X402 is a protocol that activates the HTTP 402 status code to enable instant, blockchain-based payments for web resources and APIs. It’s presented as the best way to accept digital payments.
It’s an open, internet-native payment protocol developed by Coinbase. Built around the HTTP 402 status code, x402 enables users to pay for resources via API without registration, emails, OAuth, or complex signatures.
A client, such as an AI Agent, requests a paid resource from a server, such as an API. the server responds with an HTTP 402 status code. The 402 response includes the payment requirements (amount, currency, address – often a stablecoin like USDC on a layer-2 chain like Base).
What’s X402 good at?
It offers new monetisation models, offering developers and content creators a frictionless way to earn revenue from small transactions without forcing subscriptions or showing ads.
- Monetise APIs & AI models: charge per API call, AI inference, or data access without subscriptions.
- No chargebacks or middlemen: instant USDC payments with finality, no disputes.
- Built-in compliance & security: KYT screening from Coinbase including OFAC and illicit finance.
- Real-time reporting dashboards: track revenue, balances, and transactions effortlessly.
X402 as a protocol has 0 fees for either the customer or the merchant. It enables instant settlement, accepting payments at the speed of the blockchain. It is blockchain agnostic, meaning it isn’t tied to any specific blockchain or token but is open to integration by all.
It encourages broad community participation and isn’t tied to any centralised provider. Anyone can implement or extend x402.
FLock.io is using X402 for on-chain agents
FLock.io is building the infrastructure for decentralised, privacy-first AI. By integrating X402, we are solving the payment problem for on-chain, autonomous AI agents. With FLock API and X402, there’s going to be an explosion of applications powered by FLOCK, our token.
For example, the AI astrologist, vibe coded using the FLock stack, can be found on vibe.flock.io. It’s also a Base app. Check it out while registration is open!
X402 is the perfect fit for FLock.io and on-chain AI agents. We are creating a unified gateway for on-chain Agents to pay for the brains (AI Models).
AI Agents are designed to operate independently, executing complex, multi-step tasks across the web. They need to be able to:
- Read an article (pay a micro-toll).
- Access an API (pay per-inference).
- Use a decentralised computing service (pay per-second).
- Buy a piece of data (pay per-query).
X402 is a privacy-first way of paying. This aligns perfectly with FLock’s core commitment to decentralised AI development. Read our recent blog to find out why blockchain isn’t a cliché at FLock.io – it’s essential for scaling federated learning.
No personally identifiable information (PII) required by X402. Agents and users transact using only their wallet address. There is no registration, no email, no OAuth, and no collection of PII required to make a payment.
The x402 protocol is stateless and works purely on HTTP headers and blockchain transactions. This is the only way to facilitate the high-frequency, autonomous payments that a fully operational AI agent requires.
More about FLock.io
FLock.io’s ecosystem consists of three key components: AI Arena, a platform for competitive model training; FL Alliance, a privacy-focused collaboration framework that enhances models while preserving data sovereignty; and Moonbase, our new rewards layer and AI model marketplace. We also just launched our API Platform.
Find out more about FLock.io by reading our docs and blogs. See a sneak peak of new launches coming in Q4 2025.
For future updates, follow FLock.io on X.
