axiom-json-canonicalizer

JCS RFC 8785 — Canonical JSON. Convert any JSON to a deterministic, byte-to-byte identical canonical form. Use when you need to sign, hash, or compare JSON regardless of whitespace or key order. Pure stdlib, no LLM, no cloud.

Version: 1.0.1 Axioma Tools

Converts any JSON to a canonical form per RFC 8785 (JCS).

What this skill does

• Object keys sorted lexicographically (post-NFC)
• No insignificant whitespace
• Numbers: ECMAScript shortest round-trip
• Strings: NFC-normalized, surrogate-pair safe
• Output: UTF-8 bytes (byte-to-byte stable)

When to use this skill

• ✅ Sign OAuth/JWT payloads (canonicalize before signing)
• ✅ Hash JSON for integrity verification
• ✅ Compare semantically-equivalent JSON
• ✅ Build tamper-evident audit logs
• ❌ Need pretty-printing (use json.dumps indent)
• ❌ Need JSON5/JSONL/JSONC (different specs)

Usage

python3 axiom_json_canonicalizer.py input.json > canonical.json
python3 axiom_json_canonicalizer.py input.json --verify canonical.json

from axiom_json_canonicalizer import canonicalize
canon_bytes = canonicalize(json_obj)  # UTF-8 bytes

Validation

Check	Status
Unit tests	81 cases
Performance	<100ms
Security	Pure stdlib, no injection
Determinism	Byte-to-byte stable
License	Apache-2.0

Last updated: 2026-06-14