Circle has launched Nanopayments on testnet, offering developers a new infrastructure layer for ultra-small, gas-free $USDC transactions.
The product is built on Circle Gateway and designed to serve the emerging agentic economy, where AI agents and autonomous software need to make rapid, sub-cent payments for services such as pay-per-call APIs, usage-based billing, and machine-to-machine marketplaces.
The core challenge Nanopayments aims to solve is an economic one. Traditional payment rails carry fixed fees and overhead that make sub-cent transactions impractical, while even low-cost blockchain transactions can impose fees that dwarf the payment itself.
Circle’s approach sidesteps this by aggregating transactions off-chain and settling them on-chain in batches, effectively reducing the per-transaction gas cost to zero for developers, with Circle absorbing the settlement costs at the batch layer.
The system follows the x402 open standard, allowing any agent to pay any merchant without creating an account or adding a credit card. When an agent initiates a payment, it signs an authorization that’s validated by the Nanopayments API, the merchant gets instant confirmation, and actual on-chain settlement happens periodically in the background.
In a blog post, Circle highlighted an early proof of concept in which an autonomous robot dog used Nanopayments to pay for its own recharging in $USDC, a glimpse at what fully autonomous economic actors might look like.
The testnet supports multiple blockchains, including Arbitrum, Base, Ethereum, Optimism, Polygon, and Sonic.
The launch comes amid explosive growth in the stablecoin sector, whose market capitalization now exceeds $314 billion, up 37% from $228 billion a year ago, according to DeFiLlama.
Circle’s $USDC is the second-largest stablecoin with nearly $79 billion in circulation, according to Coingecko.
The company has been steadily building out its platform beyond $USDC issuance. In spring 2025, it launched the Circle Payments Network, a platform for real-time, low-cost cross-border payments using stablecoins. It later unveiled Gateway, a chain abstraction tool that lets $USDC holders access a unified balance across supported blockchains, and introduced Arc, a Layer-1 blockchain purpose-built for $USDC transactions.
