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x402 is the HTTP-native payment standard for agents and APIs. Tachyon ships an x402 facilitator wired directly into the protocol, when a client agent pays a 402-protected endpoint, the payment is delivered as a confidential intent. The merchant’s address and the amount stay private, and the payer can pay from any chain with any supported token.
Live on testnet. Mainnet coming soon.

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Why this is different from a vanilla x402 facilitator

A standard x402 facilitator publishes the merchant’s wallet address in the payment challenge, settles on a fixed chain, and exposes the amount on-chain. Repeated payments link agents to merchants and expose pricing. The Tachyon facilitator handles the settlement leg as a confidential intent: the merchant’s address rotates per payment (a fresh stealth address), the amount is not visible on-chain, and the payer can pay from a chain other than the merchant’s settlement chain. Cross-chain hops are handled by the facilitator.

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Where it fits

  • AI agents paying for compute, data, or model APIs
  • API providers charging per call without exposing pricing or volume
  • Machine-to-machine commerce where merchant identity must stay confidential

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How it works (integrator view)

The merchant runs an x402-enabled API. When a client calls without payment, the API responds with HTTP 402 and a payment challenge. The client’s SDK or agent runtime hands the challenge to the Tachyon facilitator, which constructs a confidential intent on the client’s behalf, settles, and returns proof of payment. The original API call is then retried with the proof attached.

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What’s confidential

  • Merchant wallet address, rotates per payment
  • Amount paid for any individual call
  • Link between agent and merchant across calls
What’s necessarily public: the agent’s funding action on its source chain (a public ERC-20 approval, for example). The 402 challenge itself does not reveal the merchant’s settlement address.

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Pay from any chain, any supported token

Funding flexibility is core to the integration:
  • The merchant picks the chain and asset they receive in (set when they configure their x402 server).
  • The client picks the chain and asset they pay from. If the client’s funding chain isn’t a Tachyon-supported source chain, the facilitator hops via Near Intents or Relay before the confidential settlement leg.

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Integration shape, merchant

import { tachyonX402 } from "@tachyon/x402";

app.use(
  tachyonX402({
    network: "testnet",
    receivingChain: "base",
    receivingToken: USDC_BASE,
    pricing: { "/resource": "0.01" }, // USD per call
  })
);

app.get("/resource", (req, res) => {
  res.json({ data: "..." });
});

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Integration shape, client agent

import { TachyonAgent } from "@tachyon/agent";

const agent = new TachyonAgent({
  network: "testnet",
  funding: { chain: "arbitrum", token: USDC_ARB },
});

const response = await agent.fetch("https://api.example.com/resource");
The agent transparently handles the 402, pays via the facilitator, and retries.
The client/merchant TypeScript helpers shown above are WIP. Today, point your x402 facilitator URL at https://facilitator.tachyon.pe and use any standard x402 middleware, the Tachyon facilitator speaks the standard protocol.

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Try it

x402 facilitator

Point any x402 client at this facilitator URL.

x402 integration guide

Stand up a 402-protected API and pay it from a client agent on testnet.