As software and AI agents become more autonomous, they increasingly need a way to pay for data and services that are as simple and composable as the internet itself. The x402 standard introduces a new payment model built directly into web protocols, enabling small, programmatic payments that can be executed automatically by applications and AI agents—without the friction of traditional checkout flows or account-based systems.
x402 is an open payment standard that utilizes the existing HTTP 402 “Payment Required” code. Using the x402 standards, developers can create AI applications and agents that are able to make on-chain transactions This allows them to use digital currency (like stablecoins or HBAR) over the internet as easily as sending an HTTP request, which is how websites normally communicate.
Instead of sending users to checkout pages or requiring complex crypto wallet interactions, x402 lets apps request and confirm payments directly with standard web traffic, using a facilitator like Blocky402. Paying for an API call, a small amount of data, or a single AI agent task can now happen automatically in the background – with minimal user friction and without requiring sellers or merchants to manage complex crypto transactions.
This standard is especially well suited for micropayments – small, one-off payments for goods or services that cost cents or fractions of a cent – such as accessing research papers, reports, paywalled sensor data, or services like OCR and translations. With x402, users, and agents, can retrieve exactly what they need without creating logins, subscribing to services, or dealing with high fees typical of traditional bank or credit card payments.
As a result, x402 is a natural fit for AI agents that rely on real-time data to conduct research and complete tasks, using a protocol that works seamlessly within existing internet infrastructure.
How it works
The x402 schema supports many different payment schemes. Hedera’s exact payment scheme uses partially signed transactions with a unique model where the facilitator pays the gas fees and submits transactions, as shown below.
When a client requests a resource such as a gated website or piece of data, the resource server responds with a 402 “payment required” message that describes the cost of access and how payment should be made.
Once the payment required message is received by the client, they construct a payment transaction that transfers the required asset and amount to the resource server. The client signs this transaction with their own wallet to authorize the payment, but intentionally leaves it incomplete so that the designated fee-paying party can finalize it later. This partially signed transaction is then sent back to the resource server as proof of intent to pay.
The resource server itself does not settle the payment on-chain. Instead, it forwards the proposed transaction to a facilitator for verification. The facilitator checks that the transaction is well-formed, valid, and that the funds are available from the client’s account.
Once verified, the facilitator adds its own signature to cover gas fees and submits the fully signed transaction to the blockchain for settlement. After the payment is successfully confirmed on-chain, the facilitator notifies the merchant server. With payment finalized, the merchant server completes the original request and grants the client access to the requested resource.
While facilitators are not strictly required in this flow, they significantly reduce operational overhead by removing the need for merchants to manage gas fees, currency exchange, or asset bridging themselves.
x402 Facilitators
An x402 facilitator is a service that verifies x402 payment payloads and submits the corresponding transactions to a blockchain on behalf of the client. Once the transaction is successfully settled on-chain, the facilitator returns a confirmation so the merchant can deliver the requested resource.
These x402 facilitators remove the friction for merchants, handling any gas fees and even changing cryptocurrency if the client or user is paying in a different currency, or has a stablecoin on a different blockchain than the one the merchant accepts.
Within the x402 ecosystem, a facilitatory typically:
- Verifies payment signatures and validity
- Settles payments on-chain by broadcasting transactions
- Supports multiple networks and payment schemes
- Operates independently from other facilitators
BlockyDevs’ x402 Facilitator is an open source facilitator for the x402 protocol. It provides the infrastructure to verify and settle x402 payments across multiple blockchain networks, including Hedera testnet V1, Base, Solana, Arbitrum, Optimism, and Avalanche.
x402 and digital currency opens the door for agentic payments at scale
As AI quickly grows and evolves, everyday tasks become more and more efficient, with some tasks being taken over completely by AI. AI agents are complex software that combine the powers of different AI inference models with tools and integrations to access data and other services. By creating multi-step workflows, and utilizing multiple AIs with different specialized functions, agents can carry out novel tasks such as managing a project or scheduling a meeting.
Industry analysts now argue that agentic AI will become a primary interface to software and the internet itself. Firms like IDC, Deloitte, and IBM all predict that a growing share of everyday digital work will be carried out by AI agents acting on users’ behalf rather than by people manually navigating applications and workflows.
In order to enable AI agents to carry out these complex tasks, many agents will need to have the ability to make payments on a users’ behalf. Giving agents access to traditional bank accounts introduces logistical hurdles and security concerns. No one wants to give an AI unlimited access to their funds, and opening a separate bank account or credit card to limit funds and access requires a human identity check, high fees, and a complex process.
This is where digital currencies come into play. With crypto payment rails like Hedera, new functionality is unlocked:
- You can create almost an unlimited number of accounts with a set amount of funds in each (much like virtual credit cards, but cheaper and easier).
- Unlike traditional bank accounts, there is no requirement to check the identity or ‘humanness’ of an owner of a payment account – meaning AI Agents can create, manage, and use payment accounts as needed
- Digital currencies like HBAR are programmable, which means you can set conditions and limits on the execution of transactions. For example, with Hedera you can:
- Grant an ‘allowance’ to an account with specific limits on what that allowance can be spent on
- Using-EVM based smart contracts to hold funds in escrow until predefined conditions are met
Together, these capabilities allow payments to be tightly scoped, automated, and governed by code – rather than by manual oversight.
x402 represents a fundamental shift in how payments can function on the internet — moving from complex wallet interactions and a lack of a standardized checkout experience to seamless, protocol-level transactions that happen as naturally as loading a webpage, and feel like the payment flows users are used to.
Developers can now monetize APIs and data with minimal infrastructure while choosing their own settlement methods, assets, and facilitators. Agents gain the autonomy to discover, access, and pay for resources in real time, without human intervention. More broadly, x402 makes micropayments practical at internet scale, turning digital resources into assets that can be fairly priced and instantly monetized
As AI agents become primary interfaces to the digital world, x402 provides a missing payment layer that lets them operate independently — transforming the internet into a place where both data and value can move together seamlessly.
Together, the x402 standard and networks like Hedera point toward a new model for how software and AI agents exchange value on the internet. As autonomous systems become first-class participants online, they require payment infrastructure that offers control, predictability, and security — so agents can transact within clearly defined limits, costs are predictable in advance, and payments can be executed safely without human intervention. By pairing x402’s internet-native payment flow with Hedera’s programmable and predictable settlement layer, developers gain the foundation needed to let AI agents not just consume data, but pay for it autonomously, reliably, and at scale.
