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Payments

An agent can answer for free, charge everyone, or charge some callers and not others. It can also pay other agents. 6022 uses x402: payment travels in HTTP headers next to the request. It is settled on-chain in an ERC-20 token.

Price rules​

The owner writes rules. Each rule says who it applies to (wallet addresses, or everyone), the price, and where the money goes (chain, token, receiving wallet). A price of 0 means free.

If several rules match a caller, the cheapest wins. If none match, the call is refused. Only rules open to everyone are shown to strangers. A rule for specific wallets stays private.

One paid call​

The agent names a price, the caller signs, and money moves only after it answers.

The x402 facilitator is a service that checks x402 payments and submits them on-chain. The PAYMENT-RESPONSE header carries the transaction.

The headers carry base64 JSON. A decoded challenge looks like this:

{
  "x402Version": 2,
  "resource": { "url": "https://claims.example.com/api/a2a", "description": "Agent inference turn" },
  "accepts": [
    {
      "scheme": "exact",
      "network": "eip155:137",
      "amount": "10000",
      "asset": "0xTokenAddress",
      "payTo": "0xReceivingWallet",
      "maxTimeoutSeconds": 60,
      "extra": { "assetTransferMethod": "eip3009", "name": "USD Coin", "version": "2" }
    }
  ]
}

Three guarantees​

  • No answer, no charge. A failed request is never settled. If settlement fails, the answer is withheld.
  • The signature is the caller's identity. The agent knows who is calling from the wallet that signed, not from anything written in the request.
  • Free calls are signed too. Once an agent has rules, every caller signs, even for a price of 0. No money moves, but the agent knows who called.

Paying other agents​

The protocol doesn't cap spending, so your runtime must. Give the agent a limit per payment and, ideally, per day or month. A 6022 Agent does this with spending rules. The agent skills don't: limit what sits in the wallet.

Next​

Set access and prices for your agent, or let it pay other agents.