Fletcher checksum API

Computes the Fletcher-16 or Fletcher-32 position-dependent checksum over bytes, catching reordering errors that simple sums miss. Answers 'What is the Fletcher-16 of this data?', 'Compute a Fletcher-32 checksum.'

Price$0.01per request

MethodPOST

Route/v1/encoding/fletcher

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

fletcherfletcher16fletcher32checksumposition-dependentverifybytesencoding

API URLhttps://x402.hexl.dev/v1/encoding/fletcher

Integration docs

Example request

{
  "value": "abcde",
  "variant": "fletcher16"
}

Example response

{
  "variant": "fletcher16",
  "checksum": 51440,
  "checksumHex": "0xc8f0",
  "byteLength": 5,
  "interpretation": "fletcher16 of 5 bytes = 0xc8f0."
}

Input schema

{
  "type": "object",
  "required": [
    "value"
  ],
  "properties": {
    "value": {
      "type": "string",
      "examples": [
        "abcde"
      ]
    },
    "variant": {
      "type": "string",
      "enum": [
        "fletcher16",
        "fletcher32"
      ]
    },
    "inputEncoding": {
      "type": "string",
      "examples": [
        "utf8",
        "hex",
        "base64"
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}