SYNTHORA regwatch: x402 Registry Watch: signed Ed25519 deltas of the x402/A2A endpoint reg

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x10800a5a5B9d72251566EC651E862A8b4B427dE0",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "50000",
    "maxTimeoutSeconds": 300
  }
]

{
  "bazaar": {
    "info": {
      "input": {
        "body": {
          "limit": 10,
          "since": "2026-01-01",
          "slug": "x402"
        },
        "bodyType": "json",
        "method": "POST",
        "type": "http"
      },
      "output": {
        "example": {
          "niche": "registry_watch",
          "ok": true,
          "result": {
            "as_of": "2026-08-05T16:48:43Z",
            "count": 0,
            "cursor": null,
            "feed": [],
            "source": "registry-watch"
          }
        },
        "type": "json"
      }
    },
    "schema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "properties": {
        "input": {
          "additionalProperties": false,
          "properties": {
            "body": {
              "properties": {
                "limit": {
                  "type": "integer"
                },
                "since": {
                  "type": "string"
                },
                "slug": {
                  "type": "string"
                }
              },
              "required": [
                "slug"
              ],
              "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": {
              "niche": {
                "type": "string"
              },
              "ok": {
                "type": "boolean"
              },
              "type": "object"
            },
            "type": {
              "type": "string"
            }
          },
          "required": [
            "type"
          ],
          "type": "object"
        }
      },
      "required": [
        "input"
      ],
      "type": "object"
    }
  },
  "delivery": {
    "behaviour": "if the service FAILS (invalid input, timeout, stale cache, withdrawn product, malformed output) you receive 402 and are NOT charged",
    "note": "unlike the signature -- which you verify BEFORE paying -- this one is checked afterwards, on-chain, from your own wallet",
    "order": "compute -> failure gate -> verify -> settle -> deliver",
    "policy": "no-charge-on-service-failure",
    "scope": "this covers service FAILURE, not verdict quality",
    "verify": "after a request of yours FAILS, check your own wallet on Base: no USDC settlement to our payTo will exist for it. If we had charged you, the transfer would be public and permanent"
  },
  "signature": {
    "alg": "ed25519",
    "canon": "json:sort_keys+separators(,:)+ensure_ascii+utf8",
    "envelope": "{result, attestation:{alg,pubkey,sig,canon}}",
    "jwksUrl": "https://api.hergertsynthora.com/.well-known/jwks.json",
    "publicKeyUrl": "https://api.hergertsynthora.com/pubkey",
    "sigEncoding": "hex(64B raw)",
    "verify": "recompute canon from envelope.result, then VerifyKey(bytes.fromhex(pubkey)).verify(canon, bytes.fromhex(sig)) -- no name to trust, verify the signature yourself"
  }
}

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

const res = await fetch("https://api.hergertsynthora.com/v1/regwatch");
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.hergertsynthora.com/v1/regwatch")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header