HTTP 402 Payment Required β the open protocol for AI agent micropayments. 40 organizations, 8+ blockchains, $600M+ annualized settlement. Here's every piece and how they fit together.
Launched July 2026 under the Linux Foundation. Neutral, vendor-independent governance for the x402 protocol standard. Technical steering committee established, executive director search underway.
Adyen, AWS, American Express, Circle, Cloudflare, Coinbase, Fiserv, Google, Mastercard, Monad Foundation, MoonPay, Ripple, Shopify, Solana Foundation, Stellar, Stripe, Visa β plus 23 general members.
Official Coinbase reference implementation. Battle-tested, used in production by the largest facilitator.
Official TypeScript SDK. NPM package with full x402 v2 support: EIP-712 signatures, CAIP-2 network IDs, batch settlement.
Official Python SDK. pip-installable with FastAPI/Flask middleware for servers and requests-based client for buyers.
Community-built, production-grade. Axum middleware, self-hostable facilitator, full v2 spec compliance.
One-line buyer SDK. Call pay() on any x402-enabled endpoint. Simplest integration path for agent developers.
Full-stack x402 v1.1.0 implementation with ERC-20 support. Active development (July 2026).
Facilitators handle the USDC settlement layer β they verify payment, manage wallets, and relay transactions on-chain. Pick one or self-host.
| Facilitator | Chains | Settlement | Best For |
|---|---|---|---|
| Coinbase | Base, Ethereum, Arbitrum, Optimism, Polygon, Solana | ~2s avg | Production scale, multi-chain |
| Cloudflare | Base, Ethereum | ~2s | Edge deployment, CDN-native |
| Self-hosted (x402-rs) | Any EVM | Configurable | Full control, privacy |
| AgenticPay (Solana) | Solana | ~1s | Solana-native agents |
Where AI agents discover, buy, and sell services. Each marketplace is a directory of x402-enabled APIs that agents can call and pay for autonomously.
173 services. 312K+ requests processed. 2800+ free trials. USDC on Base. No KYC. Register with one curl command. Agents append ?trial=1 to test any endpoint free. Built-in wallet generation. 5% platform fee.
Web search and data APIs at $0.001/call. Production-scale agent consumption. One of the earliest x402 adopters.
619 microservices marketplace. Data enrichment, validation, and transformation APIs for AI agents.
117+ MCP tools for crypto data: token security, wallet intelligence, market signals. Pay-per-tool-call.
The MCP-native payment execution layer. Non-custodial x402 wallet with spend governance, human-in-the-loop approvals, and NVIDIA NeMo Agent Toolkit integration. 97M+ monthly MCP downloads ecosystem.
MCP-native pay-per-tool-call on Solana. Self-hosted facilitator, Eliza plugin, Vercel AI SDK helpers. By Krystian GwizdaΕa.
Pay-per-parse web extraction at $0.0174/call. MCP-native, x402-enabled. Practical example of monetized MCP tools.
| You want to⦠| Start here | Time |
|---|---|---|
| Monetize an API for AI agents | minia2a Register β | 30 seconds |
| Add payment to your MCP server | agentpay-mcp β | 15 minutes |
| Build an x402 API from scratch | coinbase/x402 SDK β | 1 hour |
| Try an agent payment right now | minia2a Free Trial β | 10 seconds |
| Join the hackathon ($100K+) | Hackathon Guide β | Aug 23, Bengaluru |
| Read the protocol spec | x402 Foundation Spec β | 20 minutes |
List your API on minia2a. Agents discover it. They pay in USDC. You earn. 173 services already live. 500 free credits when you register.
π° Register Your API βx402 is the dominant HTTP 402 protocol, but it is not alone. As of August 2026, three protocols compete to be the payment layer for AI agents:
| Protocol | Settlement | Backers | Live Since |
|---|---|---|---|
| x402 | USDC on Base L2 | Coinbase, Cloudflare, Linux Foundation (40+ members) | Oct 2025 |
| L402 | Bitcoin Lightning | Lightning Labs | Mar 2020 |
| MPP | Rail-agnostic (USDC, fiat, BTC) | Stripe, Tempo Labs, Visa | Mar 2026 |
minia2a is protocol-agnostic β agents discover services here and pay via whichever protocol the service uses. Read the full comparison β