// GLOSSARY -- X402

What is a Micropayment?

2 min read Updated

A micropayment is a financial transaction for a very small amount — typically under $1 and sometimes fractions of a cent — enabled by low-fee payment rails like crypto on Layer 2 chains, supporting pay-per-use pricing for AI services and APIs.

WHY IT MATTERS

Traditional payment rails make micropayments impossible. Credit card fees ($0.30 + 2.9%) mean a $0.01 payment costs more in fees than the payment itself. This forces subscription models even when pay-per-use would be more efficient.

Crypto on L2 chains changes the economics. A USDC transfer on Base costs fractions of a cent — making a $0.001 payment for a single API call economically viable. This enables entirely new pricing models for AI services: pay per token, per API call, per agent action.

For the agentic economy, micropayments are foundational. An AI agent paying $0.01 per web search, $0.001 per data query, and $0.05 per API call needs micropayment rails. x402 was designed exactly for this — HTTP-native micropayments using stablecoins.

HOW POLICYLAYER USES THIS

PolicyLayer controls agent micropayments — the backbone of pay-per-use AI services. Per-transaction minimums prevent dust transactions, daily/weekly caps bound total micropayment spending, and rate limits prevent rapid-fire payment abuse.

FREQUENTLY ASKED QUESTIONS

What makes crypto micropayments feasible?
L2 chains like Base have sub-cent transaction fees, enabling payments as small as fractions of a cent to be economically viable. On Ethereum L1, gas fees make micropayments impractical.
How do micropayments work with x402?
An agent requests a paid resource, the server responds with an x402 payment requirement (e.g., $0.01 in USDC on Base), the agent signs a payment, and the server verifies it and provides the resource. The whole flow is automatic.
Won't thousands of micropayments add up to large sums?
Yes, that's exactly why spending controls matter. An agent making 10,000 micropayments at $0.01 each spends $100. PolicyLayer's cumulative budgets cap total spending regardless of individual transaction sizes.

FURTHER READING

Enforce policies on every tool call

Intercept is the open-source MCP proxy that enforces YAML policies on AI agent tool calls. No code changes needed.

npx -y @policylayer/intercept
github.com/policylayer/intercept →
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