98% of AI Agent Payments Use USDC, Raising Systemic Risk Concerns

The machine-to-machine payments era has a blind spot: almost everything runs on a single stablecoin. A new report from crypto market-maker Keyrock — produced in collaboration with Coinbase and blockchain firm Tempo and authored by researcher Ben Harvey — finds that more than 98% of agent-to-agent settlements over the past year used Circle’s USDC. Researchers warn that this concentration creates a systemic exposure the industry is largely overlooking: a regulatory action, a de-peg, or a prolonged outage affecting Circle could leave the fast-growing “agent economy” with no practical settlement alternative. Why stablecoins dominate Between May 2025 and April 2026, autonomous AI agents settled roughly $70 million across 176 million transactions — an average payment of about $0.31. Those microtransaction economics explain why legacy rails never fit: credit-card networks typically charge per-transaction fees around $0.30, making sub-dollar payments uneconomical. Crypto rails and stablecoins remove the fixed-fee barrier, allowing tiny automated payments (for example, an agent paying a few cents to query a weather API) to function at scale. Snapshot of the agent economy - Total agent settlements May 2025–Apr 2026: $70M across 176M transactions (≈$0.31 average) - Share settled in USDC: >98% - Registered agents by end of Q1 2026: >104,000, listed across 15+ directories/registries - Corporate activity: over $8 billion deployed in acquisitions by incumbents positioning for the new payment stack Rapid growth and institutional interest Harvey frames the past 12 months as a move from concept to live ecosystem. Market incumbents are already reacting: Keyrock’s report notes billions in acquisition capital flowing to capture slices of what’s becoming a new payments stack centered on autonomous software rather than human users. AI agents are already building Web3 projects, launching tokens, trading, and autonomously interacting with protocols and services. The wider belief in agent-driven finance A CoinGecko survey of 2,632 crypto users from April found 87% would let AI agents manage at least 10% of their crypto portfolio. Circle CEO Jeremy Allaire has predicted billions of agents operating with stablecoins on users’ behalf within five years — a future that would further entrench whatever settlement rails dominate today. The risk question Keyrock and its partners stress the trade-off: stablecoins solved a pressing technical and economic problem for microtransactions, but the market’s de facto reliance on a single issuer concentrates operational, regulatory, and reserve risks. The report calls for industry-wide attention to contingency planning and diversification as transaction volumes scale. Bottom line Stablecoins enabled a practical machine-payment layer where traditional payment systems couldn’t. But as the agent economy grows fast, the heavy dependence on USDC represents a single point of failure the crypto industry can no longer afford to ignore.