561 Group Market

Byte Array to RFC 4648 Base64

Encode a byte-integer array as canonical, padded RFC 4648 Base64, retaining the declared media type. Binary data is never decoded or changed. Up to 65536 bytes; malformed requests refused before payment.

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/bytes-base64
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": 300000,
  "bodySchema": {
    "type": "object",
    "additionalProperties": false,
    "properties": {
      "bytes": {
        "type": "array",
        "items": {
          "type": "integer",
          "minimum": 0,
          "maximum": 255
        },
        "maxItems": 65536
      },
      "mediaType": {
        "type": "string",
        "minLength": 1,
        "maxLength": 128,
        "description": "MIME type carried with the bytes; it is retained, not inferred."
      }
    },
    "required": [
      "bytes",
      "mediaType"
    ]
  }
}

Example request

{
  "method": "POST",
  "url": "https://market.561.group/v1/data/bytes-base64",
  "headers": {
    "accept": "application/json",
    "content-type": "application/json"
  },
  "body": {
    "bytes": [
      102,
      111,
      111,
      98,
      97,
      114
    ],
    "mediaType": "text/plain"
  }
}

Output

{
  "schema": {
    "type": "object",
    "additionalProperties": false,
    "required": [
      "mediaType",
      "contentBase64"
    ],
    "properties": {
      "mediaType": {
        "type": "string",
        "minLength": 1,
        "maxLength": 128,
        "description": "MIME type carried with the bytes; it is retained, not inferred."
      },
      "contentBase64": {
        "type": "string",
        "maxLength": 87384
      }
    }
  },
  "example": {
    "mediaType": "text/plain",
    "contentBase64": "Zm9vYmFy"
  }
}

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 '{"bytes":[102,111,111,98,97,114],"mediaType":"text/plain"}' --url 'https://market.561.group/v1/data/bytes-base64'

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

Machine-readable