// GLOSSARY -- BLOCKCHAIN & CRYPTO FUNDAMENTALS

What is USDC?

1 min read Updated

USDC (USD Coin) is a fully-reserved, dollar-pegged stablecoin issued by Circle, available on multiple blockchains, and widely used as the default payment currency for AI agent transactions through protocols like x402.

WHY IT MATTERS

USDC is the stablecoin of choice for the agentic economy. Coinbase's x402 protocol uses USDC on Base for agent payments. Circle's developer tools make USDC integration straightforward. And its regulatory posture (fully reserved, regularly audited) makes it suitable for compliant financial operations.

USDC is available on Ethereum, Base, Solana, Polygon, Arbitrum, Avalanche, and many other chains. Cross-chain USDC transfers are supported through Circle's CCTP (Cross-Chain Transfer Protocol), enabling agents to operate across multiple networks.

For developers building agent financial systems, USDC provides the predictability needed for budgeting and policy enforcement. A $1,000 daily spending limit is exactly $1,000 in USDC — no volatility adjustments needed.

HOW POLICYLAYER USES THIS

USDC is the default currency for PolicyLayer spending controls on Base and other EVM chains. Spending limits, transaction caps, and budgets are denominated in USDC, providing dollar-denominated financial control for agent operations.

FREQUENTLY ASKED QUESTIONS

Is USDC always worth exactly $1?
Very nearly. USDC typically trades within fractions of a cent of $1. It briefly depegged to ~$0.87 during the March 2023 SVB crisis but quickly recovered. Long-term, it's extremely stable.
Which chain is best for USDC agent payments?
Base is the primary chain for x402 agent payments — fast, cheap ($0.001 transactions), and backed by Coinbase. Arbitrum and Polygon are also popular for low-cost USDC transactions.
Can Circle freeze USDC?
Yes. Circle can blacklist addresses, typically for legal compliance (sanctions, law enforcement). This is a tradeoff of regulated stablecoins — more trustworthy but with centralized control.

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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