561 Group Market

JSON to Deterministic CBOR

Encode one ordinary JSON value as RFC 8949 deterministic CBOR. Return exact bytes in a canonical Base64 application/cbor carrier and both byte lengths. Text spelling and own map keys are preserved; no Unicode normalization. Finite numbers only; negative zero and unpaired surrogates refused. Maximum 65536 JSON/CBOR bytes, 8192 parsing events and depth 64. No tag invention, storage or upstream API.

Price
from $0.0012 USDC per request (starting price; the 402 response quotes the exact amount for your input)
Network
Base mainnet, eip155:8453, settled in USDC through the Coinbase CDP facilitator
Method and URL
POST https://market.561.group/v1/data/cbor-json-encode
Response type
application/json
Seller
Causeway Services (561 Group)

Input contract

Input that fails this contract is refused with a 4xx status before any payment is requested.

{
  "maxBytes": 524800,
  "bodySchema": {
    "type": "object",
    "additionalProperties": false,
    "required": [
      "value"
    ],
    "properties": {
      "value": {
        "type": [
          "object",
          "array",
          "string",
          "number",
          "boolean",
          "null"
        ],
        "description": "Ordinary JSON, at most 65536 UTF-8 bytes, 8192 nodes/parsing events and depth 64. Finite numbers, well-formed Unicode, no negative zero."
      }
    }
  }
}

Example request

{
  "method": "POST",
  "url": "https://market.561.group/v1/data/cbor-json-encode",
  "headers": {
    "accept": "application/json",
    "content-type": "application/json"
  },
  "body": {
    "value": {
      "a": 1,
      "b": [
        true,
        null,
        "café"
      ]
    }
  }
}

Output

{
  "schema": {
    "type": "object",
    "required": [
      "carrier",
      "byteLength",
      "jsonByteLength"
    ],
    "properties": {
      "carrier": {
        "type": "object",
        "additionalProperties": false,
        "required": [
          "mediaType",
          "contentBase64"
        ],
        "properties": {
          "mediaType": {
            "const": "application/cbor"
          },
          "contentBase64": {
            "type": "string",
            "maxLength": 87384
          }
        }
      },
      "byteLength": {
        "type": "integer",
        "minimum": 1,
        "maximum": 65536
      },
      "jsonByteLength": {
        "type": "integer",
        "minimum": 1,
        "maximum": 65536
      }
    }
  },
  "example": {
    "carrier": {
      "mediaType": "application/cbor",
      "contentBase64": "omFhAWFig/X2ZWNhZsOp"
    },
    "byteLength": 15,
    "jsonByteLength": 31
  }
}

How to buy with x402

  1. Send the request without payment. The server answers 402 Payment Required with a base64 JSON PAYMENT-REQUIRED header holding the amount, asset, network and payee.
  2. Have your wallet sign an EIP-3009 transferWithAuthorization for exactly those terms (an x402 client library does this for you).
  3. Repeat the identical request with the signed payload in the PAYMENT-SIGNATURE header.
  4. The server verifies, runs the operation, settles, and returns 200 with the result and a PAYMENT-RESPONSE header carrying the settlement receipt.

Read the price without paying

curl --include --request POST --header 'accept: application/json' --header 'content-type: application/json' --data-raw '{"value":{"a":1,"b":[true,null,"café"]}}' --url 'https://market.561.group/v1/data/cbor-json-encode'

This request authorizes nothing; it returns the live payment terms. Read the full explanation of x402.

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