561 Group Market

JSON Records to RFC 4180 CSV

Convert JSON records to RFC 4180 CSV with CRLF, quoted headers and escaped fields. Explicit column order; only scalar fields, with null rendered as empty. Returns CSV text in a JSON envelope. Up to 64 KiB, 4096 rows.

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/json-to-csv
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": 102400,
  "bodySchema": {
    "type": "object",
    "additionalProperties": false,
    "properties": {
      "columns": {
        "type": "array",
        "items": {
          "type": "string"
        },
        "minItems": 1,
        "maxItems": 256
      },
      "records": {
        "type": "array",
        "items": {
          "type": "object"
        },
        "maxItems": 4096
      }
    },
    "required": [
      "columns",
      "records"
    ]
  }
}

Example request

{
  "method": "POST",
  "url": "https://market.561.group/v1/data/json-to-csv",
  "headers": {
    "accept": "application/json",
    "content-type": "application/json"
  },
  "body": {
    "columns": [
      "name",
      "note"
    ],
    "records": [
      {
        "name": "Ada",
        "note": "a,b"
      }
    ]
  }
}

Output

{
  "schema": {
    "type": "object",
    "properties": {
      "text": {
        "type": "string",
        "maxLength": 65536
      },
      "mediaType": {
        "const": "text/csv"
      },
      "standard": {
        "const": "RFC4180"
      },
      "rowCount": {
        "type": "integer"
      }
    },
    "required": [
      "text",
      "mediaType",
      "standard",
      "rowCount"
    ]
  },
  "example": {
    "text": "\"name\",\"note\"\r\n\"Ada\",\"a,b\"\r\n",
    "mediaType": "text/csv",
    "standard": "RFC4180",
    "rowCount": 1
  }
}

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 '{"columns":["name","note"],"records":[{"name":"Ada","note":"a,b"}]}' --url 'https://market.561.group/v1/data/json-to-csv'

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

Machine-readable