x402: The Ubiquitous Open Payment Protocol by Coinbase

x402 has dominated discussions recently. Launched by Coinbase in early 2025, this open payment protocol creates a blockchain-agnostic micro-payment system, leveraging the HTTP 402 status code as its conceptual foundation.

Designed for AI agents and autonomous transactions, x402 enables instant settlement in stablecoins like USDC without account registration, subscriptions, or complex signature processes. It represents a novel transaction model bridging Web2 and Web3.

Envision a future where an on-chain AI executes your command to purchase a MacBook, configures it with specific specifications, finds the best online price, and instantly pays the merchant via x402.

No platform account needed, no dependency on subscriptions or credit cards. x402 simply pays on behalf of your agent.

We are in an extraordinary era where AI will permeate every aspect of daily life.

What is the x402 protocol?

In essence, x402 is Coinbase's payment protocol that allows AI agents to pay for services using USDC or similar stablecoins instantly, eliminating account creation or subscriptions. Inspired by the nearly forgotten HTTP status code 402 Payment Required, Coinbase revitalized this concept. Their aim is to make payments as seamless as requesting a web page—an Internet-native primitive.

Currently, everyday users should prioritize three key areas: payments, AI identity, and funds provenance/tracing.

The three core roles in x402

• Buyer: the AI agent
• Seller: the service provider
• Transaction channel: the x402 protocol

Technical references:

• EIP-3009 spec: https://eips.ethereum.org/EIPS/eip-3009
• ICRC-1 standard: https://github.com/dfinity/ICRC-1
• x402 protocol docs: https://github.com/coinbase/x402
• ICP developer docs: https://internetcomputer.org/docs

For instance, consider the meme project Ping. Traditionally, users would register accounts and complete KYC to access services or tokens (PING). With x402, direct purchases are possible. In this scenario:

• Buyer: a player
• Seller: the meme project team
• Channel: x402 protocol

The transaction flow resembles familiar on-chain transfers but utilizes x402 instead of ERC-20 processes. x402 is primarily tailored for autonomous on-chain transactions by AI agents.

AI agents + crypto: a new stablecoin payment flow

Core characteristics

• Machine-to-machine payments: AI agents autonomously conduct commercial exchanges.
• Cross-chain compatibility: Supports Base, Solana, Polygon, NEAR, and others.
• Enterprise-grade backing: Involves Coinbase, Cloudflare, Visa, Google, AWS, and more.
• Open standard: The x402 Foundation drives ecosystem growth.

Notable ecosystem projects performing well with x402

PayAINetwork ($PAYAI)

• Market cap: ≈ $4.8M (fully diluted)
• Funding: $5M seed led by Borderless Capital (May 2025)
• Core business: B2B/B2C agent marketplace where autonomous agents settle in USDC via x402
• Tech progress: v1 PayAI accelerator deployed on Base; processed 42k+ autonomous microtransactions since July 2025

daydreamsagents ($DREAMS)

• Market cap: ≈ $7.6M
• Funding: angel round with Solana Ventures and Archetype participating (Apr 2025)
• Core business: TypeScript-first framework; DREAMS Router handles USDC micro-payments via x402 for model inference
• Tech progress: Router migrated from testnet to Base mainnet; >1.3M model calls per month

peaq ($PEAQ)

• Market cap: ≈ $50M (circulating), ≈ $324M fully diluted
• Funding: ~$43M total raised, latest $15M strategic round by Borderless & Generative Ventures
• Core business: DePIN-focused L1; integrated native x402 support in Aug 2025
• Tech progress: Enables M2M payments for 850k+ connected devices; two DePIN dApps transitioned to x402 payment flows

GoKiteAI

• Funding: $18M Series A led by General Catalyst & PayPal Ventures
• Core business: "The agent internet base layer"—provides agent identity, programmable permissions, and payment infrastructure
• Token plan: tokenomics published; TGE scheduled for Q1 2026

Other chain projects—examples below:

Questflow — a multi-agent economy driven by x402

On-chain multi-agent orchestration where agents autonomously coordinate tasks, generate economic value without human input. Central to this is $SANTA—a cluster of 13 autonomous agents managed by Questflow and published via @virtuals_io.

AurraCloud ($AURA) — agent orchestration layer for x402

Develops an orchestration layer for AI agents deployable in minutes, integrating MCP and crypto APIs. With smart wallets, agents autonomously pay for services and execute transactions without human oversight.

mrdn_finance ($MRDN) — x402 payment coordinator (flagship)

A flagship x402 project incubated by UOS, featuring mechanisms including:

• 1% protocol treasury fee to establish long-term fiscal stability.
• 2% cashback rewards (gradually decaying, halving schedule) to encourage early adoption.
• $MRDN per-transaction rewards to attract developers and agent builders.
• Multi-chain support: Base, Optimism, Unichain—expanding x402 across superchains.

itsgloria_ai ($GLORIA) — x402 data & API hub

The data and API hub for the x402 ecosystem, enabling agents to access and transact real-time data on a pay-per-use, trustless basis. It bridges the data economy with the agent economy, allowing information monetization for agents.

The first x402 meme — pingobserver

How can ordinary people participate early in x402?

x402 remains in its early stages but embodies the convergence of payments + machine/AI + on-chain settlement, aligning with future trends. Early adopters like developers, websites, and AI agents gain first-mover advantages. As chain-level infrastructure, x402 resembles a fundamental tech shift more than a typical speculative token venture.

Capital rapidly identifies opportunities—x402-themed plays are emerging in public markets. On-chain represents a blue ocean: key exchanges and infrastructure providers are racing to establish foundations—

For newcomers without accounts, start with research (e.g., this overview): 2026 Latest Top 10 Cryptocurrency Exchange Rankings 🔥【Must Save】, pre-register where applicable, and conduct basic due diligence to position in this emerging blue ocean.