Agent Payments Protocol (AP2)
Building a Secure and Interoperable Future for AI-Driven Payments with x402 on Solana
The Agent Payments Protocol connects Merchant Ecosystems with Payment Ecosystems through AI Agents
🚨The Foundational Gap: A Crisis of Trust
The evolution of digital interaction is entering a new phase, moving beyond direct human interaction with websites and apps to conversational and delegated task execution by AI agents. In commerce, this means agents will manage everything from routine purchases to complex product research and price negotiation.
Despite its promise, the rise of agentic commerce exposes a critical vulnerability: today's payment systems were designed for direct human interaction. When an autonomous agent initiates a payment, fundamental questions arise that current systems cannot answer:
Authorization & Auditability
What verifiable proof exists that the user granted the agent specific authority to make a particular purchase?
Authenticity of Intent
How can a merchant be certain that an agent's request accurately reflects the user's true intent, free from errors or AI "hallucinations"?
Accountability
In the event of a fraudulent or erroneous transaction, who is accountable? The user, the agent's developer, the merchant, or the payment network?
⚠️The Risk of a Fragmented Ecosystem
Without a common standard, the industry risks developing a patchwork of proprietary, closed-loop solutions. This would create:
For Users
A confusing and inconsistent experience, where their preferred agent may only work with a limited set of merchants or payment methods.
For Merchants
High integration costs to support multiple, non-standard agent payment integrations, creating barriers for small businesses.
For Payments Ecosystem
An inability to collect common signals across all agent transactions to consistently mitigate fraud.
💡The Solution: x402 + Google AP2 on Solana
The Agent Payments Protocol (AP2) combined with x402 on Solana creates an open, interoperable protocol for agent payments. This protocol, designed as an extension for emerging agent-to-agent (A2A) and model-context protocols (MCP), provides:
A2A + AP2
Agent-to-Agent Commerce
Google's Agent Payments Protocol enables standardized agent-to-agent transactions with verifiable digital credentials and mandates.
x402 Protocol
HTTP 402 Micropayments
Native HTTP 402 "Payment Required" responses enable seamless pay-per-use AI inference and services with Solana micropayments.
Shielded Facilitation
Privacy-Preserving Payments
Decentralized and private AI transactions with shielded facilitation for trading, shopping, and agent-to-agent commerce.
Solana Native
On-Chain + Off-Chain
High-speed, low-cost Solana transactions for both on-chain and off-chain AI services with SPL token payments.
🌐 Beyond Traditional Commerce
x402 + AP2 on Solana enables a new paradigm for decentralized AI, trading, transacting, shopping, and facilitating - both on-chain and off-chain. With shielded facilitation, users maintain privacy while agents conduct commerce autonomously within defined mandates.
🏛️Guiding Principles for a Trusted Agent Economy
Openness and Interoperability
A non-proprietary, open extension for A2A and MCP protocols. Any compliant agent can securely transact with any compliant merchant.
User Control and Privacy by Design
Users have granular control and transparent visibility over their agents' activities. Sensitive information is protected through encryption.
Verifiable Intent, Not Inferred Action
Transactions are anchored to deterministic, non-repudiable proof of intent from all parties, addressing agent hallucination risks.
Clear Transaction Accountability
The protocol provides supporting evidence that helps establish accountability and liability principles for all participants.
🎭The Actors in the Ecosystem
The User
The human individual who initiates a commerce task by delegating it to their Agent. The ultimate source of intent and financial authority.
User Agent / Shopping Agent
The AI surface that the user directly interacts with. Understands user needs, discovers products, interacts with merchants, and obtains user's signed authorization.
Credentials Provider (CP)
A specialized entity responsible for secure management and execution of payment credentials. Holds knowledge of available payment methods and handles tokenization.
Merchant Endpoint (ME)
A web interface, MCP endpoint, or AI agent operating on behalf of an entity which expects to receive payment in return for products or services.
Dark Solana Facilitator
Solana-native x402 payment facilitator providing shielded on-chain verification, settlement, replay protection, and privacy-preserving facilitation.
🔐Trust Anchors: Verifiable Digital Credentials
The protocol uses Verifiable Digital Credentials (VDCs) as trust anchors - cryptographically signed documents that establish and communicate trust between parties:
Cart Mandate
Defines what items can be purchased and under what conditions, establishing the scope of the agent's authority.
Intent Mandate
Captures the user's explicit authorization for a specific transaction, providing non-repudiable proof of intent.
Payment Mandate
Authorizes the payment execution with specific limits, providing visibility to the payments ecosystem.
Get Started with x402 + AP2
Explore our x402-enabled AI services with shielded facilitation on Solana. Pay-per-use with micropayments for AI inference, NFT minting, and agent-to-agent commerce.
AP2 specification licensed under Apache License, Version 2.0 by Google.
x402 Protocol implementation on Solana with shielded facilitation by Dark Solana.