561 Group Market

HTML Character Reference Decoding

Decode HTML named and numeric character references with explicit text or quoted-attribute context. Native WHATWG rules retain context-dependent semicolon behavior and map invalid numeric/surrogate/out-of-range references to their specified replacements. Decoding is one pass; it does not parse or strip markup. Input maximum65536 UTF-8 bytes; result maximum1048576 JSON bytes. No script execution, model or fetching.

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/html-entity-decode
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": 1048576,
  "bodySchema": {
    "type": "object",
    "required": [
      "text"
    ],
    "properties": {
      "text": {
        "type": "string",
        "maxLength": 65536,
        "description": "Maximum65536decoded UTF-8 bytes; full JSON escaping fits the request envelope."
      },
      "context": {
        "enum": [
          "text",
          "attribute"
        ],
        "default": "text"
      }
    },
    "additionalProperties": false
  }
}

Example request

{
  "method": "POST",
  "url": "https://market.561.group/v1/data/html-entity-decode",
  "headers": {
    "accept": "application/json",
    "content-type": "application/json"
  },
  "body": {
    "text": "&CounterClockwiseContourIntegral; &notit; € �",
    "context": "text"
  }
}

Output

{
  "schema": {
    "type": "object",
    "required": [
      "text",
      "byteLength",
      "context"
    ],
    "properties": {
      "text": {
        "type": "string"
      },
      "byteLength": {
        "type": "integer",
        "minimum": 0
      },
      "context": {
        "enum": [
          "text",
          "attribute"
        ]
      }
    }
  },
  "example": {
    "text": "∳ ¬it; € �",
    "byteLength": 17,
    "context": "text"
  }
}

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 '{"text":"&CounterClockwiseContourIntegral; &notit; € �","context":"text"}' --url 'https://market.561.group/v1/data/html-entity-decode'

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

Machine-readable