561 Group Market

CID Inspection and Base Conversion

Inspect canonical CIDv0/v1 and convert to CIDv1 in base16, base32 (default), base36, base58btc or base64url. Preserve numeric codec/hash codes and exact digest; return source version and binary CID. No block decoding, content verification or retrieval; unknown codes are retained as numbers, not interpreted. Maximum 1024 ASCII input characters and 511 binary CID bytes. Refuse nonminimal varints, trailing bytes, noncanonical text and invalid CIDv0 shape 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/cid-inspect
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": 544768,
  "bodySchema": {
    "type": "object",
    "additionalProperties": false,
    "required": [
      "cid"
    ],
    "properties": {
      "cid": {
        "type": "string",
        "minLength": 1,
        "maxLength": 1024,
        "description": "Canonical CIDv0 or CIDv1 in one supported base; maximum 511 binary bytes."
      },
      "base": {
        "enum": [
          "base16",
          "base32",
          "base36",
          "base58btc",
          "base64url"
        ]
      }
    }
  }
}

Example request

{
  "method": "POST",
  "url": "https://market.561.group/v1/data/cid-inspect",
  "headers": {
    "accept": "application/json",
    "content-type": "application/json"
  },
  "body": {
    "cid": "QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zR1n",
    "base": "base32"
  }
}

Output

{
  "schema": {
    "type": "object",
    "required": [
      "sourceVersion",
      "version",
      "codec",
      "base",
      "cid",
      "bytesBase64url",
      "multihash"
    ],
    "properties": {
      "sourceVersion": {
        "enum": [
          0,
          1
        ]
      },
      "version": {
        "const": 1
      },
      "codec": {
        "type": "integer",
        "minimum": 0
      },
      "base": {
        "type": "string"
      },
      "cid": {
        "type": "string",
        "maxLength": 1024
      },
      "bytesBase64url": {
        "type": "string"
      },
      "multihash": {
        "type": "object",
        "required": [
          "code",
          "digestLength",
          "digestBase64url",
          "bytesBase64url"
        ],
        "properties": {
          "code": {
            "type": "integer",
            "minimum": 0
          },
          "digestLength": {
            "type": "integer",
            "minimum": 0
          },
          "digestBase64url": {
            "type": "string"
          },
          "bytesBase64url": {
            "type": "string"
          }
        }
      }
    }
  },
  "example": {
    "sourceVersion": 0,
    "version": 1,
    "codec": 112,
    "base": "base32",
    "cid": "bafybeihdwdcefgh4dqkjv67uzcmw7ojee6xedzdetojuzjevtenxquvyku",
    "bytesBase64url": "AXASIOOwxEKY_BwUmvv0yJlvuSQnrkHkZJuTTKSVmRt4UrhV",
    "multihash": {
      "code": 18,
      "digestLength": 32,
      "digestBase64url": "47DEQpj8HBSa-_TImW-5JCeuQeRkm5NMpJWZG3hSuFU",
      "bytesBase64url": "EiDjsMRCmPwcFJr79MiZb7kkJ65B5GSbk0yklZkbeFK4VQ"
    }
  }
}

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 '{"cid":"QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zR1n","base":"base32"}' --url 'https://market.561.group/v1/data/cid-inspect'

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

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