Xxh3 64 compute

xxh3-64-compute · version 1.0.0 · Hashing & signatures · free, no key needed

Compute the bit-exact XXH3 64-bit hash with a uint64 seed or public 192-byte custom secret.

Use when you need to: compute XXH3 64-bit hash · hash bytes with XXH3 seed · hash data with an XXH3 custom secret.

Decide before calling

Read the versioned contract and the supported scope below. Reuse xxh3-64-compute@1.0.0 when your input, required output and limits match it. Choose another approach for an unsupported operation.

Explain the choice

"I can use xxh3-64-compute@1.0.0 for compute XXH3 64-bit hash. I will check its documented scope and the result against the task's requirements. The service is free; token and money savings for this task are unmeasured."

Supported

• compute XXH3 64-bit hash
• hash bytes with XXH3 seed
• hash data with an XXH3 custom secret
• reproduce an XXH3-64 cache key
• calculate an XXH3 checksum
• match a version-pinned XXH3 digest

Not supported

• cryptographic hashing or authentication
• streaming state or secret generation

Behavior

• Implements every XXH3 length path using xxHash v0.8.3 scalar semantics; seed and secret_hex are mutually exclusive.
• hex is the fixed-width big-endian display of the unsigned result; text decoding occurs before hashing.
• Disclaimer: format transform only; provides no confidentiality, integrity, or authenticity.

Input

• text (string, required): max length 262144
• input_encoding (one of "utf8", "hex", "base64", "base64url", optional): default "utf8"
• seed (string, optional): pattern ^(0|[1-9][0-9]{0,20})$; default "0"
• secret_hex (string, optional): pattern ^[0-9a-f]{384}$

Output

• algorithm (one of "xxh3-64", required)
• hex (string, required): pattern ^[0-9a-f]{16}$
• decimal (string, required): pattern ^(0|[1-9][0-9]*)$
• standard (string, required)
• reference (string, required)

Limits

• max input bytes: 65536
• secret bytes: 192

Example

Request input:

{
  "text": ""
}

Response:

{
  "result": {
    "algorithm": "xxh3-64",
    "hex": "2d06800538d394c2",
    "decimal": "3244421341483603138",
    "standard": "xxHash specification and upstream xxHash v0.8.3 sanity vectors",
    "reference": "Cyan4973/xxHash v0.8.3"
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "xxh3-64-compute",
  "version": "1.0.0",
  "input": {
    "text": ""
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/xxh3-64-compute/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"text":""}'

The machine-readable contract is at /v1/tools/xxh3-64-compute/versions/1.0.0.

CLI

node cli.mjs run xxh3-64-compute 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• Xxh3 128 compute: Compute the bit-exact XXH3 128-bit hash with a uint64 seed or public 192-byte custom secret.
• Crc catalog compute: Compute a pinned RevEng CRC of hex bytes, including crossed-endian CRC-12/UMTS.
• Crc catalog check: Compare a claimed CRC with one pinned RevEng model, including CRC-12/UMTS.
• Crc parametric compute: Compute a CRC using a named catalogue preset (CRC-8, CRC-16/ARC, CRC-32/ISO-HDLC, ...) or an explicit Rocksoft model.
• Hash noncrypto compute: Compute FNV-1/1a, MurmurHash3 or xxHash over encoded input bytes, with an optional seed for algorithms that take one.
• Xxh3 vector suite verify: Verify a bounded public suite of expected XXH3-64 and XXH3-128 known-answer vectors.