x402 Protocol

HYRE uses the x402 protocol for payment — an extension of HTTP that turns the 402 Payment Required status code into a machine-readable payment flow. Agents pay per request with no API keys, no OAuth, and no subscriptions.

How x402 Works

Agent sends request without payment

curl https://mpp.hyreagent.fun/defi/tvl

The server returns HTTP 402 with payment requirements in the response body.

Server returns 402 with payment details

{
  "x402Version": 1,
  "accepts": [
    {
      "scheme": "exact",
      "network": "solana",
      "maxAmountRequired": "1000",
      "resource": "https://mpp.hyreagent.fun/defi/tvl",
      "payTo": "7G73PLhKvAPBGTzG5ESAE4coE7QrVeTTKfhTxQZbyGgC",
      "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
      "description": "Total Value Locked across chains",
      "maxTimeoutSeconds": 300
    }
  ]
}

Agent signs payment and retries

The agent constructs a payment payload, signs it with its wallet, base64-encodes it, and attaches it as the X-PAYMENT header.

curl -X POST https://mpp.hyreagent.fun/defi/tvl \
  -H "X-PAYMENT: eyJ4NDAyVmVyc2lvbiI6MSwi..." \
  -H "Content-Type: application/json" \
  -d '{"chain": "solana"}'

Facilitator verifies and settles

The HYRE server forwards the payment to a facilitator that verifies the signature and settles the USDC transfer on-chain. If valid, the server processes the request and returns data.

Facilitators

HYRE uses two facilitators depending on the payment chain:

Chain	Facilitator	URL	Gas
Solana	Dexter	`https://x402.dexter.cash`	Sponsored by HYRE
Base	PayAI	`https://facilitator.payai.network`	Caller pays (~$0.01)
SKALE	PayAI	`https://facilitator.payai.network`	Free (sFUEL)

The facilitator acts as a neutral third party:

Verify — Checks the payment signature is valid and the amount is sufficient.
Settle — Executes the USDC transfer on-chain after the server delivers data.

Payment Header Format

The X-PAYMENT header contains a base64-encoded JSON object:

{
  "x402Version": 1,
  "scheme": "exact",
  "network": "solana",
  "payload": {
    "signature": "<base58-encoded-solana-signature>",
    "transaction": "<base64-encoded-transaction>"
  }
}

For EVM chains (Base, SKALE), the payload contains an EIP-712 signed authorization instead of a Solana transaction.

Discovery

Agents can discover HYRE’s payment requirements programmatically:

curl https://mpp.hyreagent.fun/openapi.json | jq '.info["x-payment-protocols"]'

curl https://mpp.hyreagent.fun/.well-known/agent-card.json | jq '.capabilities.x402'

curl https://mpp.hyreagent.fun/.well-known/x402 | jq

Pay-To Addresses

Chain	Address
Solana	`7G73PLhKvAPBGTzG5ESAE4coE7QrVeTTKfhTxQZbyGgC`
Base (EVM)	`0xb5998e11E666Fd1e7f3B8e8d9122A755eec1E9b7`
SKALE (EVM)	`0xb5998e11E666Fd1e7f3B8e8d9122A755eec1E9b7`

Root paths (/) only accept Solana payments. Use /base/* for Base and /skale/* for SKALE. Sending an EVM payment to a root path returns a 402 redirect hint.

​x402 Protocol

​How x402 Works

​Facilitators

​Payment Header Format

​Discovery

​Pay-To Addresses

x402 Protocol

How x402 Works

Facilitators

Payment Header Format

Discovery

Pay-To Addresses