Semantic
As AI agents graduate from simple tasks to sophisticated workflows — researching, reasoning, and acting autonomously across the internet — they hit a wall: payments. Consider an agent tasked with generating a daily investment memo. It pulls market data from Kaiko, queries on-chain analytics from The Graph, runs sentiment analysis through an LLM, and compiles the output into a formatted report. Four providers, four API keys, four billing accounts, four sets of credentials to provision, rotate, and monitor. All before the agent has done anything useful. Add a fifth provider tomorrow and the whole stack needs re-plumbing. This is the bottleneck. Every provider requires its own authentication, its own payment method, its own billing relationship. The agent can’t just pay for what it needs and move on. It needs a human to pre-negotiate access at every layer.Agents need to pay for things
The use cases are already here. What’s missing is the infrastructure to make them work.Data
A research agent purchasing a premium dataset, a live feed, or a proprietary API mid-workflow.
Compute
An orchestrator spinning up inference on demand, paying per-token or per-job to the cheapest available provider.
Capabilities
A coding agent spinning up a cloud sandbox to test its output. Paid instantly, no API key required.
Goods
A procurement agent ordering physical inventory, booking logistics, or purchasing supplies.
The infrastructure is missing
Traditional payment rails weren’t designed for machines transacting with machines at the speed and scale that agents demand. What’s needed is a fundamentally different approach.Human Oversight & Guardrails
Spend limits, approval flows, and kill switches. Agents operate within boundaries their owners define.
Accountability & Authorization
Every payment is tied to an identity and a policy. Know which agent spent what, why, and whether it was authorized.
End-to-End Traceability
Full audit trail from intent to settlement. Every request, authorization, and transfer is logged and verifiable.
New Rails
Near-instant finality, low and predictable fees, privacy by default, and programmable transactions.
How Semantic works
Semantic provides an x402-compatible payment facilitator that makes agent payments as simple as an HTTP header. We leverage USD₮, the world’s most liquid stablecoin, on chains purpose-built for stablecoin transactions: Plasma and Stable. These chains deliver the speed, cost, and privacy properties that agent commerce requires, without the congestion and gas volatility of general-purpose L1s.x402 Protocol
x402 Protocol
The x402 protocol extends HTTP with a native payment layer. When a resource requires payment, the server responds with
402 Payment Required and the client settles automatically, no redirects, no checkout flows, no API keys.USDâ‚®0 on Plasma & Stable
USDâ‚®0 on Plasma & Stable
USDâ‚®0 supports EIP-3009 (
transferWithAuthorization), enabling gasless, signature-based transfers. The payer signs, the facilitator submits, no gas tokens needed in the agent’s wallet.BTC Support (Coming Soon)
BTC Support (Coming Soon)
Native Bitcoin payments via Spark invoices, bringing the world’s hardest asset into the agent economy alongside stablecoins.
Get started
Quick Setup
Get your first payment working in 5 minutes
API Reference
Explore the facilitator endpoints
Roadmap
See what’s coming next
Ready to build? Start with the Quick Setup to get your first agent payment working in under 5 minutes.