Introduction
Abstract
v402 is built on the x402 protocol and extends it with multi-language SDK support and multi-chain capabilities. Through standardized APIs and SDKs, v402 bridges the gap between content providers and AI platforms, offering a unified way to verify access, execute payments, and coordinate on-chain settlements — all without human intermediaries.
Background
The rise of AI-generated content and intelligent crawlers has changed how information is found and consumed. Yet creators face a core problem — their work powers AI models without fair pay or attribution.
Traditional paywalls and ads can’t handle automated or cross-platform access, and most monetization APIs still depend on outdated Web2 systems with centralized keys and manual billing. This creates trust issues, slows payments, and blocks interoperability between agents and apps.
A new standard is needed — one that enables direct, verifiable, and low-cost payments between machines. Coinbase’s x402 protocol introduces this foundation. By using HTTP 402 (“Payment Required”) as a programmable signal, x402 allows AI agents to request, verify, and settle microtransactions automatically — forming the native payment layer for the AI-powered internet.
Problem Statement
The modern web and AI ecosystems face deep structural issues. As autonomous agents begin to transact and consume information at scale, the current web infrastructure struggles to support fair and efficient value exchange.
Uncompensated Access — AI crawlers and agents extract value from human-created data without transparent attribution or payment.
High Friction Payments — Legacy billing APIs and API-key systems rely on centralized authentication and manual settlement, unfit for autonomous or cross-platform transactions.
Fragmented Standards — Each platform enforces its own access and billing logic, blocking interoperability and automation.
v402 solves this by introducing a unified API and SDK layer integrated with x402, enabling agents and platforms to perform verifiable, low-cost micropayments directly — turning content access into an on-chain, programmable financial interaction.
System Overview
v402 introduces a three-layer architecture:
Index Platforms (Visitors / Agents) — Entities that request or index content, integrated via the v402_index_client SDK.
Content Providers (Websites / APIs) — Entities that host and monetize content, using the v402_content_provider SDK.
Facilitator Layer — The middleware that verifies, settles, and records transactions, implemented through the v402_facilitator service.
Together, these components create an interoperable ecosystem for low-cost, automated content monetization built upon the x402 protocol standard.
v402 Auth3.0
Beyond simply building on top of x402, v402 fully embraces its cryptographic payment standard to redefine how access control, billing, and usage authorization work on the Internet. In Web2 architectures, API access is mediated through API keys, centrally issued and verified by service providers.This model creates friction, introduces trust dependencies, and limits interoperability across platforms.v402 replaces this legacy mechanism with cryptographic identity and authorization:
Public Keys as Credentials
Every caller (AI agent, crawler, or platform) is identified by its public key, serving as a self-sovereign credential instead of a database-issued API key. This ensures authentication and authorization are both verifiable and portable across ecosystems.
Usage Points as On-Chain Tokens
Instead of storing usage balances in a centralized database, v402 issues usage points as Web3 tokens, representing compute or content access credits.These tokens can be transferred, staked, or redeemed, enabling open-market dynamics for API consumption.
On-Chain Accounting for Every Interaction
All usage, payments, and settlements are recorded directly on-chain. Whether it’s a platform billing event or an AI agent completing a content transaction, the data is verifiable, transparent, and tamper-proof.
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