Verify a hash-linked agent commerce journey and issue a signed portable receipt

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x7BEcA68DD9aC733D4de6b16d16B85Dc391c071e2",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "10000",
    "maxTimeoutSeconds": 60
  }
]

{
  "bazaar": {
    "info": {
      "input": {
        "body": {
          "events": [
            {
              "actor": "agent:buyer",
              "artifact_sha256": "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
              "kind": "intent",
              "observed_at": 1700000000,
              "sequence": 0
            },
            {
              "actor": "agent:seller",
              "artifact_sha256": "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
              "kind": "delivery",
              "observed_at": 1700000001,
              "sequence": 1
            }
          ],
          "journey_id": "example-commerce-journey"
        },
        "bodyType": "json",
        "discoverable": true,
        "method": "POST",
        "type": "http"
      },
      "inputSchema": {
        "properties": {
          "events": {
            "items": {
              "required": [
                "sequence",
                "kind",
                "actor",
                "artifact_sha256",
                "observed_at"
              ],
              "type": "object"
            },
            "minItems": 2,
            "type": "array"
          },
          "journey_id": {
            "type": "string"
          }
        },
        "required": [
          "journey_id",
          "events"
        ],
        "type": "object"
      },
      "output": {
        "example": {
          "receipt": {
            "signature": "base64url"
          },
          "verification": {
            "score": 100,
            "verdict": "verified"
          }
        },
        "type": "json"
      }
    },
    "schema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "type": "object"
    }
  }
}

curl "https://phion.systems/v1/paid/journeys/verify"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

const res = await fetch("https://phion.systems/v1/paid/journeys/verify");
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

import httpx
res = httpx.get("https://phion.systems/v1/paid/journeys/verify")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header