Monetization models
x402 lets you price machine usage in ways subscriptions never could. The right model depends on how your value scales.
Micropayment per request
Charge from a fraction of a cent up to dollars per API call. Ideal for high-volume agent workloads where flat tiers don’t fit.
LLM token pricing
Bill agents by token usage for LLM endpoints — like usage-based AI APIs, but without accounts or subscriptions.
Outcome-based pricing
Charge only when the agent gets value — a successful scrape, extraction or code run. Align price with delivered results.
Streaming micropayments
Charge continuously as an agent consumes a stream of data or compute, settling in small increments over time.
How it works on your server
- Gate the route. Return HTTP 402 with payment requirements on protected endpoints.
- Set the price. Put the amount in USDC base units (use the converter) and your wallet as
payTo. - Verify. Check the agent’s
X-PAYMENTproof — yourself or via a facilitator — before serving. - Get paid. Funds settle to your wallet on Base in about two seconds, per request.
Generate a working challenge body and copy server code with the free 402 response builder.
Tools to monetize with
Curated open-source projects that add a 402 paywall or payment layer to your API or MCP server — stars live from GitHub.
Drop-in x402 payment middleware for Flask APIs. Machine-to-machine payments on Base chain.
⭐ 67The best way to monetize AI applications & MCP, using x402, CDP Smart Wallets & Paymaster
⭐ 48Add x402 payment support to your API in seconds. Easily accept x402 payments and sell one-time API access—all with a single configuration and no changes to your existing codebase.
⭐ 11Frequently asked questions
How do I monetize an AI agent or API?
Add x402 middleware to your API or MCP server. When an agent hits a paid endpoint it receives an HTTP 402 with payment details, pays in USDC on Base, and retries — fully automated, with no API keys or subscriptions to manage.
What is the best way to charge AI agents for API use?
The x402 protocol, built on HTTP 402, is the leading open standard. It enables per-call micropayments in USDC with no subscriptions, no API keys and no human intervention, so you can price exactly per request.
Can AI agents pay for services autonomously?
Yes. An agent holds a crypto wallet, detects the HTTP 402 response, executes the on-chain payment and retries the request — all without a human. That is what makes agent-native monetization possible.
Which tokens can I charge in?
x402 primarily uses USDC, a dollar stablecoin, on Base, Ethereum or Solana. Stablecoins are preferred because they remove price volatility and let you set predictable micropayment prices.
Related: x402 protocol, paid MCP servers, x402 SDKs, ecosystem map, agent wallets, or browse 1149 x402 projects among 1500+ tools.