Author: @BlazingKevin_, the Researcher at Movemaker

Google recently released the AP2 protocol, which outlines the underlying rules for payments and transactions in the upcoming Agent economy. Its core task is to complete the final piece of the puzzle from "AI analysis" (based on MPC) and "Agent execution" (based on A2A) — "value settlement," attempting to standardize the payment process for AI Agents, formalize the interaction rules for Agents, and ultimately promote AI Agents that can autonomously conduct business activities on behalf of users.

The primary application scenario of AP2 targets the core areas of traditional internet, such as e-commerce and subscription services. This means its original design intention is to solve the problem of how to securely delegate payment authorization from humans to AI within the existing commercial framework. This will directly impact the direction of e-commerce operations, freeing users from the actions of clicking "buy" and "subscribe," and shifting to "intent delegation" and "rule setting" for AI Agents.

Based on this logic, we need to assess the impact of AP2 on the cryptocurrency industry more cautiously. It is not born for Web3 native scenarios but incorporates cryptocurrency payments (especially stablecoins) as an optional, integrated payment option within its grand framework. Therefore, rather than saying AP2 will trigger an explosion of AI, it is more accurate to say it provides an interface for cryptocurrency assets to enter mainstream AI applications.

Understanding the Preceding Protocols of AP2: MCP and A2A

The existence of AP2 is built upon the development paths of the two preceding protocols, MCP and A2A. Understanding the essence and limitations of these two protocols is key to grasping the true intentions of AP2. MCP addresses the connection issue between AI and tools, while A2A attempts to solve the collaboration issue between AI and AI.

What is MCP? Allowing AI to Truly Engage with the Real World

The essence of large language models (such as Gemini and GPT) is that they are "super brains" isolated from the real world. They possess vast amounts of static knowledge but cannot access real-time information or directly operate any external software. When a user issues a command like "Help me book a flight to Osaka tomorrow," it cannot fulfill this request because it lacks the ability to interact with booking websites.

The introduction of the MCP (Model Context Protocol) is aimed at solving the problem of how AI communicates with the external environment. MCP defines a standardized communication format that allows AI to make requests to external tools (such as databases and APIs) and receive responses. It can be understood as installing a phone for this "locked room brain."

The MCP (Model Context Protocol) is a "standard intercom system" born to break down this locked room.

It is driven by industry giants like Anthropic and aims to solve the problem of how AI can interact with external data and tools (such as databases, software, and blockchains) in a standardized manner. Through this "intercom," AI models can issue requests to the outside world in a standard language, while the MCP system is responsible for accurately relaying these requests to the corresponding external tools (such as weather APIs and booking site APIs), and returning the results in a standard format once the tools have completed their tasks.

However, analyzing the current implementation of MCP, we find that it resembles an "internal phone" that can only dial a few preset numbers.

Currently, the ability of AI to call external tools heavily relies on the vertical integration of platform providers. For example, Gemini defaults to and exclusively calls Google Search when a search is needed; its code execution also runs in a sandbox environment built by the platform. This model has direct implications for users and developers:

• For users: The upper limit of AI capabilities is locked by the platform. Users cannot choose third-party tools they consider superior (for example, using Perplexity for AI searches or calling specific financial data APIs). The practicality of AI is thus greatly limited, and the user experience is bound within the platform's ecosystem.

• For developers: This creates a de facto market barrier. Even if developers create AI applications that far exceed the platform's built-in tools in a specific field, they cannot be fairly discovered and called by mainstream AI Agents. Innovation is stifled, and market competition is confined within a closed, platform-dominated collaborative system.

A2A: From "Internal Phone" to "Public Yellow Pages" Concept

If MCP is about giving AI the "hands and feet" to operate tools, then the A2A (Agent-to-Agent) protocol teaches independent AI Agents how to "communicate and collaborate." It is built on top of MCP and defines a set of universal rules that allow independent AI Agents developed by different companies and developers to discover each other, understand each other's capabilities, and collaboratively complete complex tasks that a single Agent cannot handle.

The significance of A2A lies in upgrading the task processing model of MCP from "individual combat" to "project subcontracting." For example, when a user presents a complex requirement like "plan a beach party in Hawaii next month," under the closed system of only MCP, individual Agents can only clumsily call the limited tools allowed by the platform one by one.

However, in the A2A concept, individual Agents can act as "contractors." They can break down the tasks and publish requests in the A2A network, seeking specialized "travel Agents," "catering Agents," and "event planning Agents" to collaborate on completion. This shift in model will have profound implications:

• For users: The capabilities of AI Agents will achieve exponential leaps. Users can confidently delegate extremely complex, cross-domain tasks, as AI is no longer a simple operator of tools but a coordinator of resources.

• For the industry: The goal of A2A is to create an open, interoperable Agent service market. It aims to solve three core issues: how to discover (establishing a mechanism similar to an Agent app store), how to understand (defining a standardized descriptive language for Agent capabilities), and how to collaborate (standardizing the processes for task allocation and progress synchronization). Once this system matures, any Agent developer that meets the standards can register their services and be fairly chosen by the market.

The Core Mechanism of AP2: Establishing a Trust and Authorization Framework for Agent Transactions

The MCP and A2A protocols address the questions of "what Agents can do" and "how to collaborate," but this immediately raises a more challenging business dilemma: when Agents begin to autonomously execute operations involving funds, who is responsible for the legality and consequences of these actions?

In traditional online payment systems, the risk control logic is based on a fundamental premise: there is a human user actively and in real-time performing operations in front of the screen. Any automated payment request initiated by a non-human will be flagged as high-risk behavior by the existing financial system. This is the most fundamental obstacle to the formation of the Agent economy. Specifically, a transaction request initiated by AI presents three unanswered questions for merchants and payment networks:

1. Authorization proof: How can it be confirmed that the user has genuinely authorized the AI to make this transaction?
2. Intent fidelity: Does the AI's specific request (such as quantity and price) accurately reflect the user's true intent, especially when the user is not monitoring in real-time?
3. Liability attribution: If a transaction goes wrong, who should bear the resulting losses?

The design of Google's AP2 protocol is precisely aimed at systematically answering these three questions. AP2 seeks to establish an open, standardized authorization and trust communication protocol among users, AI Agents, and merchants.

The core technology of AP2 is a dual authorization mechanism:

1. Real-time Authorization (Cart Mandate)

This mechanism is familiar to credit card users; when you use a credit card to make a payment on a website, your phone will pop up an authorization window. What AP2 does is this.

After the Agent completes preliminary work such as product research and price comparison, it will generate a "shopping cart" containing all transaction details and present it to the user. The execution of the transaction must wait for the user to conduct a final review and sign confirmation.

Impact Analysis: Real-time authorization is the initial form of Agent payments; it lowers the user’s entry threshold but does not fully realize the autonomy of the Agent. Its main value lies in optimizing the decision-making process before the transaction, but the final "last step" still requires human intervention.

2. Delegated Authorization (Intent Mandate)

This is the transformative part of AP2. Users can pre-set a complex set of conditional delegated instructions. For example: "Only execute the purchase process when the price of the Tesla Model Y drops by more than 20,000 yuan, using funds from account A; if account A is insufficient, then use account B."

To make this "forward delegation" trustworthy and secure, the implementation logic of AP2 is based on Verifiable Credentials (VCs):

• The user's complex delegated conditions will be compiled into a tamper-proof digital "transaction contract" (i.e., VC) signed with their encryption.
• The AI Agent must present this "contract" at each key step of task execution to prove the legality of its actions.
• All execution steps will also generate corresponding VC records, ensuring the entire process is auditable.

For merchants and clearing networks (such as Visa): They receive a "transaction contract" accompanied by the user's encrypted signature, clarifying the scope and conditions of authorization. By verifying this contract, they can gain sufficient confidence to confirm the legality of the transaction, significantly reducing fraud risk and compliance costs.

For users: This makes a truly "24/7 autonomous economic agent" possible, liberating users from high-frequency, repetitive decision-making.

In summary, the true innovation of AP2 lies not in transforming clearing networks like Visa or stablecoins, but in adding a trust semantic layer about "who is spending money, on what basis, and can be traced beyond the authorization limits" on top of them.

It aims to unify the resolution of AI payment intent confirmation issues across different clearing systems, such as fiat and cryptocurrency, thereby alleviating all parties' fundamental concerns about the uncontrollable and unverifiable behavior of Agents.

x402 Extension: Natively Embedding Cryptocurrency Payments into Agent Service Call Processes

The core technology of AP2 is designed to make AI Agents compatible with the existing human-centered financial authorization system, while the "A2A x402" extension is designed for future native, on-chain A2A payments. The x402 extension is jointly promoted by Google, Coinbase, and the Ethereum Foundation.

The technical choice of x402 originates from a long-idled internet standard — the HTTP 402 status code, defined as "Payment Required." In the past, due to the lack of standardized machine payment methods, this status code was almost never practically applied.

However, when the primary callers of APIs shift from human developers to high-frequency, automated AI Agents, the value of this protocol becomes apparent.

Traditional subscription or prepaid models are overly cumbersome and inefficient for scenarios where Agents dynamically and cross-platform call massive services on demand. The core idea of x402 is to solve this problem by natively coupling API calls with payments.

Its workflow is designed to be extremely simple and automated:

1. The AI Agent calls a paid service API.
2. The server of that service directly returns a 402 Payment Required response, which includes the information needed to complete the payment (such as the payment address, amount, and token type).
3. The Agent's built-in wallet or payment module parses this "payment bill" and automatically completes the payment on-chain (e.g., using USDC).
4. The Agent carries the on-chain payment proof and re-initiates the API request.
5. The server verifies the payment and immediately returns the data or service results required by the Agent.

This process may seem simple, but it can leverage the real-time settlement and highly programmable features of stablecoins to significantly impact the business model of AI Agent services.

Impact on AI Agents:

• Achieving true "pay-as-you-go": Agents no longer need to go through the traditional manual process of "registering an account -> binding a credit card -> selecting a subscription plan -> waiting for service activation." They can dynamically discover any service that follows the x402 standard in the network and complete payment and usage in milliseconds, providing a foundation for the autonomy and exploratory capabilities of Agents.

• Extreme cost efficiency: The payment frequency of Agents far exceeds that of humans, and their parallel task processing capabilities enable them to conduct extremely granular micro-payments and flow payments. x402 allows Agents to pay precisely based on API call frequency, returned data volume (tokens), and computation duration, perfectly linking resource consumption with costs and avoiding resource waste under traditional subscription models.

Impact on AI Service Providers:

• Dissolution of payment system protocol layers: x402 builds the capability of "access equals quote, payment equals service" directly into the communication protocol layer. Developers no longer need to build complex billing, account, and subscription management systems; they can focus on developing core services, pricing and marketing any API, data shard, or even a page component at a granular level.

• Optimizing cash flow and global settlement: With stablecoins, service providers can achieve instant, low-cost global settlements, completely freeing themselves from the lengthy settlement cycles and high fees of traditional cross-border payments. This provides unprecedented convenience for reconciling ultra-frequent, very small transactions, significantly lowering the barriers for individual developers and small teams to commercialize AI services.

Summary and Outlook: Dual Tracks in Parallel, Ecosystem Emerges

The value of the AP2 protocol lies not in its seemingly simplistic technical details but in providing the final piece of the puzzle for the commercial closed loop of the technological evolution route of MCP (connection) + A2A (collaboration) — value settlement.

By granting Agents reliable transaction capabilities, it lays the first standardized track for the entire industry to transition from the "AI tools" era to the true "Agent economy" era.

Google's layout clearly indicates its intentions: on one hand, by accommodating traditional business, it accelerates the landing of Agents in mainstream scenarios such as e-commerce and subscriptions, setting industry standards to quickly "adapt" e-commerce platforms to the involvement of AI; on the other hand, by embracing native cryptocurrency solutions, it also establishes standards for on-chain Agent-to-Agent payments.

Opportunities and Challenges: The Crossroads of Native Cryptocurrency Agents

The completion of AP2's payment capabilities will undoubtedly unlock numerous application scenarios, such as 24/7 autonomous financial management, automated corporate procurement and renewals, all of which will drive the penetration of the Agent-to-Agent economic model.

However, AP2 is an authorization framework driven top-down by tech giants, with the primary goal of solving its core business ecosystem issues. Cryptocurrency payments play a role that is "compatible" and "supportive."

This forms a positive stimulus for native cryptocurrency Agent protocols. Currently, truly decentralized, censorship-resistant, privacy-protecting Agent products centered around the core values of Web3 have yet to achieve critical technological breakthroughs and lack clear PMF.

Who can create products with native cryptocurrency qualities and innovative designs in the context of gradually clarifying industry standards will be the watershed for competition in cryptocurrency AI protocols moving forward.

Although the road ahead is unclear, some protocols in the cryptocurrency industry have already begun actively laying out around AP2 and its possibilities. From the first batch of partners, we can see a preliminary ecosystem forming:

Standards and Infrastructure: Coinbase, as the initial proposer of the x402 payment standard, is actively promoting its implementation; the Ethereum Foundation is working on establishing underlying protocols such as ERC-8004 (trust agent standard).

Entry and Wallet: MetaMask is dedicated to creating a self-custodial AI agent wallet and simplifying the user onboarding process, aiming to become a secure entry point for the Agent economy.

Public Chains and Interoperability: Mesh focuses on optimizing payment routing to ensure the success rate and efficiency of Agent payments.

Payments and Applications: Companies like Crossmint and BVNK provide multi-channel cryptocurrency and fiat payment capabilities for Agents; platforms like Questflow have already integrated the x402 micropayment system, allowing Agents to receive rewards based on task results.

Ultimately, the release of AP2 marks the initiation of the standardization process for the Agent economy. It brings unprecedented imaginative space to the industry while further concentrating the power to control these new economic rules.

For the cryptocurrency industry, this is both an excellent opportunity to integrate into the mainstream and accelerate adoption, as well as a severe test of the future dominance of the Agent economic model. How to leverage this infrastructure while carving out a differentiated path with the core values of Web3 will be a track worth watching in the coming year.

About Movemaker

Movemaker is the first official community organization authorized by the Aptos Foundation, jointly initiated by Ankaa and BlockBooster, focusing on promoting the construction and development of the Aptos ecosystem in the Chinese-speaking region. As the official representative of Aptos in the Chinese-speaking area, Movemaker is committed to building a diverse, open, and prosperous Aptos ecosystem by connecting developers, users, capital, and numerous ecological partners.

Disclaimer:

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