Avro schema fingerprint

avro-schema-fingerprint · version 1.0.0 · Structured formats · free, no key needed

Compute the CRC-64-AVRO fingerprint of an Avro 1.12.0 parsing canonical form.

Use when you need to: avro schema fingerprint · crc 64 avro fingerprint · hash avro schema canonically.

Decide before calling

Read the versioned contract and the supported scope below. Reuse avro-schema-fingerprint@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 avro-schema-fingerprint@1.0.0 for avro schema fingerprint. 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

• avro schema fingerprint
• crc 64 avro fingerprint
• hash avro schema canonically
• compute avro schema id
• stable avro fingerprint
• fingerprint avro canonical form

Not supported

• cryptographic schema hashing
• registry lookup or registration
• fingerprint arbitrary bytes

Behavior

• Implements Apache Avro Specification 1.12.0 Parsing Canonical Form and Schema Fingerprints.
• Canonical UTF-8 bytes are processed with the CRC-64-AVRO initial value and polynomial; hex is an unsigned 16-digit lowercase integer.
• This is a compact schema identifier, not a cryptographic integrity or security proof.
• Rejects forward or unresolved references and all malformed, cyclic, non-JSON, duplicate, or over-limit inputs.

Input

• schema (any JSON value, required)

Output

• canonical_form (string, required): max length 32768
• fingerprint_hex (string, required): pattern ^[0-9a-f]{16}$
• standard_version (constant "Apache Avro Specification 1.12.0", required)

Limits

• max input bytes: 16384
• max schema nodes: 512
• max depth: 32
• max fields: 128
• max output bytes: 32768

Example

Request input:

{
  "schema": "null"
}

Response:

{
  "result": {
    "canonical_form": "\"null\"",
    "fingerprint_hex": "63dd24e7cc258f8a",
    "standard_version": "Apache Avro Specification 1.12.0"
  }
}

How to call it

MCP

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

{
  "id": "avro-schema-fingerprint",
  "version": "1.0.0",
  "input": {
    "schema": "null"
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/avro-schema-fingerprint/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"schema":"null"}'

The machine-readable contract is at /v1/tools/avro-schema-fingerprint/versions/1.0.0.

CLI

node cli.mjs run avro-schema-fingerprint 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• Avro parsing canonical form: Produce the Avro 1.12.0 parsing canonical form for a bounded schema.
• Avro schema equivalence check: Decide whether two Avro schemas have identical Avro 1.12.0 parsing canonical forms.
• Asn1 der encode tree: Encode a schema-free ASN.1 node list as one canonical DER value.
• Asn1 der validate: Check one ASN.1 DER value for canonical TLV structure and return a reason.
• INI win format: Format sections and keys into stable Windows initialization-file text.
• XML exc c14n canonicalize: Exclusive XML Canonicalization 1.0 of a whole document, with an optional inclusive prefix list.