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Launch··6 min read

Launching OpenUSDC: open USDC rails for AI agents

PN
Priya Naidu
Co-founder & CEO

Today we're launching OpenUSDC, the open-source x402 payment gateway and hosted control plane for AI agents. The gateway is MIT-licensed. The SDKs are MIT-licensed. The audits are public. OpenUSDC Cloud is the optional managed dashboard on top.

We didn't set out to build payments infrastructure. We set out to build a research-agent product. After about three weeks we realized the bottleneck wasn't the model — it was money. Our agent needed to buy a search-API call here, a news article there, a few seconds of GPU somewhere else, and we were stitching together six different billing systems plus a long tail of one-off promotional credits. Every new integration was three days of paperwork.

What we wanted was a way for the agent to pay any HTTP API the way a browser pays a paywall: hit the resource, see a price, decide whether to pay, settle in stablecoin, retry. Last winter, Coinbase published a draft of the x402 standard — a tiny set of HTTP headers that did exactly that. We started implementing it the following week.

What's in the box

The 0.6 release ships with everything we've been running internally for six months.

  • openusdc gateway — a tiny middleware layer for Node, Python, Go, Rust, Deno, and Cloudflare Workers. One line of code in front of any HTTP route turns it into an x402-priced endpoint.
  • openusdc SDK — what your agent uses to pay. Wraps a wallet, signs payment headers, retries 402 responses, returns structured receipts. Supports raw EOAs, Coinbase MPC, Turnkey, and Privy out of the box.
  • openusdc cloud — a dashboard, webhook fanout, reconciliation ledger, alerts, and exports. Free tier covers the first ten thousand reconciled payments per month, forever.
  • policies — declarative JSON that bounds what an agent's wallet can do. Spend caps, allow-lists, time-bounded keys, chain pinning, the works.
  • audits — the gateway core has been audited by Spearbit; the report is in the repo. The SDK signers are audited by Trail of Bits (report dropping next month).

What we believe

Three convictions shaped the design. We'll be wrong about some of them; we'd rather be wrong loudly than be quietly cautious.

The agent economy is HTTP-shaped. Agents already spend most of their wall-clock time inside HTTP libraries. The payment layer should live there too. We resisted the temptation to invent a new protocol; x402 is a thin wrapper over plain HTTP, and we'll do everything we can to keep it that way.

The buyer and the seller need the same standard. Most existing agent-payments solutions are either buyer-side (here's a wallet, good luck) or seller-side (here's a marketplace, list your API). The interesting thing happens when one company's agent buys from another company's agent. That requires both ends to speak the same wire format. So we built both ends — and made them both open source.

Self-host has to be a real choice. The companies most likely to deploy agents at scale are also the companies least excited to depend on a startup's uptime page. The gateway runs as a 9 MB container, a 4 MB Cloudflare Worker, or a Lambda layer. Cloud is wire-compatible with the self-hosted version, so you can adopt incrementally — or not at all.

What we're shipping next

Three things on the next 90 days of the roadmap. We'd love your voice on any of them.

  1. More chains. Polygon and World Chain are next, and we're prototyping a Tron route for the Asia-Pacific corridor.
  2. Streaming payments. For token-by-token billing on streaming LLM endpoints, we're shipping an extension to the x402 wire format we're calling x402-stream. Comments welcome on the GitHub RFC.
  3. Native browser SDK. We've had a few people ask for x402 inside a browser tab — a real one, not a headless agent. We're shipping a tiny fetch shim that lets any web app prompt a connected wallet (MetaMask, Phantom, Coinbase Wallet) to settle a payment inline.

Thanks

To the engineers who quietly let us send them pull requests against their HTTP middleware libraries before the standard was finalized. To Spearbit. To everyone in our Discord who tested payment-flow edge cases at 2am. To our pre-seed investors at Northstar Ventures and Loop Capital — the rest, soon.

If you're building anything that wants to act, not just answer, take it for a spin. The Quickstart is five minutes long. We'd love to see what you ship.

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