One RFC 3161 timestamp receipt over a digest you supply

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xAC6A3A729672a786182e4A7BA29c78587fafE3b4",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "50000",
    "maxTimeoutSeconds": 60
  },
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0xAC6A3A729672a786182e4A7BA29c78587fafE3b4",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "500000",
    "maxTimeoutSeconds": 60
  }
]

{
  "bazaar": {
    "info": {
      "description": "Submit a SHA-256 digest, receive a Time-Stamp Authority's signed RFC 3161 token over it. Proof that the data you hashed existed at that time, verifiable against the authority without trusting or contacting this service.",
      "input": {
        "body": {
          "digest": "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08"
        },
        "bodyType": "json",
        "method": "POST",
        "type": "http"
      },
      "name": "satledger timestamp receipt",
      "output": {
        "example": {
          "digest": "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08",
          "timestamp_token_der_b64": "MIIS...(RFC 3161 token, base64)",
          "tsa_url": "https://freetsa.org/tsr",
          "verify": "openssl ts -reply -in token.der -text"
        },
        "type": "json"
      },
      "whenToUse": "Call this when you need to show later that something existed now - a model output, a decision, a document - and the person you will show it to has no reason to trust you. One call, no account. Keep the token; it is the evidence."
    },
    "schema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "properties": {
        "input": {
          "additionalProperties": false,
          "properties": {
            "body": {
              "description": "Send `digest` for one, or `digests` for up to 10 in a single call and a single payment. A batch is bound to one timestamp by a Merkle root, and each digest comes back with the proof that binds it there.",
              "oneOf": [
                {
                  "required": [
                    "digest"
                  ]
                },
                {
                  "required": [
                    "digests"
                  ]
                }
              ],
              "properties": {
                "digest": {
                  "description": "SHA-256 of whatever you want timestamped, as 64 hex characters. Hash it yourself; the data never leaves your side.",
                  "pattern": "^[0-9a-fA-F]{64}$",
                  "type": "string"
                },
                "digests": {
                  "description": "Up to 10 SHA-256 hashes. Requires the batch price; the single price permits one.",
                  "items": {
                    "pattern": "^[0-9a-fA-F]{64}$",
                    "type": "string"
                  },
                  "maxItems": 10,
                  "minItems": 1,
                  "type": "array"
                }
              },
              "type": "object"
            },
            "bodyType": {
              "enum": [
                "json",
                "form-data",
                "text"
              ],
              "type": "string"
            },
            "method": {
              "enum": [
                "POST",
                "PUT",
                "PATCH"
              ],
              "type": "string"
            },
            "type": {
              "const": "http",
              "type": "string"
            }
          },
          "required": [
            "type",
            "method",
            "bodyType",
            "body"
          ],
          "type": "object"
        },
        "output": {
          "properties": {
            "example": {
              "type": "object"
            },
            "type": {
              "type": "string"
            }
          },
          "required": [
            "type"
          ],
          "type": "object"
        }
      },
      "required": [
        "input"
      ],
      "type": "object"
    }
  }
}

curl "https://api.satledger.org/x402/receipt"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

const res = await fetch("https://api.satledger.org/x402/receipt");
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://api.satledger.org/x402/receipt")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header