NeoMundi Measurement Interoperability

One measurement contract. Every infrastructure.

NeoMundi measures. Your infrastructure decides.

A public, versioned, cryptographically signed contract for transporting a NeoMundi runtime measurement into your infrastructure — structured so any external system can validate it, verify its integrity and origin independently, and apply its own interpretation and policy.

JSON, machine-readable
Schema versioned
SHA-256 integrity
Ed25519 / JWS signature
Independent verification
Consumer keeps control

The contract

Two real historically signed RGC v0.1 observations from examples/ in the repository. Unmodified.

Select a section above to see what it's for.

{
  "identity": {
    "schema_version": "0.1.0",
    "request_id": "3d55da6a-8170-4480-a435-b0af0583a9fe",
    "trace_id": "00-3ff43f4daeaa44efce938d816566a094-278bf1314051a6df-01",
    "timestamp": "2026-08-17T16:43:47.547079Z",
    "system_id": "controltower-api",
    "model": "local",
    "mode": "OBS"
  },
  "provenance": {
    "measurement_version": "3.0.0",
    "normalizer_version": "1.0.0",
    "checks_emitted": 3,
    "source_batch_id": null,
    "canonicalization_method": "sorted-json-utf8"
  },
  "observation": {
    "runtime_scope": "single_request",
    "observation_window": null,
    "measurement_status": "complete",
    "measurement_coverage": 0.6,
    "observed_signals": {
      "stability_score": 0.615385,
      "coherence_score": 1.0,
      "factual_hallucination_score": 1.0,
      "semantic_instability_score": 0.0,
      "semantic_risk": 0.0,
      "observation_class": "flagged",
      "confidence": 1.0
    },
    "limitations": [
      "Measurement reflects a single runtime observation window; it is not a certification of third-party content.",
      "The governance signal is advisory only — it does not grant, refuse, suspend, or modify any execution permission.",
      "Provider/model identity is pseudonymized in this contract and cannot be reversed to the original value."
    ],
    "measurement_boundary": "This contract measures a single observed runtime signal. It does not evaluate ground truth, does not certify third-party data, and carries no execution authority."
  },
  "governance": {
    "governance_boundary": {
      "authorization_status": "not_applicable",
      "execution_permission_changed": false
    },
    "advisory": {
      "review_recommendation": "required",
      "review_trigger": ["contradiction", "overclaim", "factual_risk"],
      "recommended_review_type": ["independent_evidence_review", "human_validation"],
      "interpretation_policy": {
        "policy_id": "rgc-piste-b-advisory",
        "policy_version": "0.1.0"
      }
    }
  },
  "integrity": {
    "payload_hash": "6a605bf81bbbf1086289ea974dbfe4011206db0bc9970cfa21aaaf557627811c",
    "hash_algorithm": "sha256",
    "canonicalization": "sorted-json-utf8",
    "signature": "eyJhbGciOiJFZERTQSIsImtpZCI6Im5lb211bmRpLXJnYy0yMDI2LTAxIiwidHlwIjoiSldUIn0.eyJwYXlsb2FkX2hhc2giOiI2YTYwNWJmODFiYmJmMTA4NjI4OWVhOTc0ZGJmZTQwMTEyMDZkYjBiYzk5NzBjZmEyMWFhYWY1NTc2Mjc4MTFjIiwiaGFzaF9hbGdvcml0aG0iOiJzaGEyNTYiLCJzY2hlbWFfdmVyc2lvbiI6IjAuMS4wIiwicmVxdWVzdF9pZCI6IjNkNTVkYTZhLTgxNzAtNDQ4MC1hNDM1LWIwYWYwNTgzYTlmZSIsInRpbWVzdGFtcCI6IjIwMjYtMDgtMTdUMTY6NDM6NDcuNTQ3MDc5WiJ9.tismpbLKt5hG8vYBIF8k42xi35QFGlCZ8bMVavmz-Q0yS1OJRdUDrE5b-izvkczJZh-LvBvmLwBk8RDHdTP_AA",
    "signer_identity": "neomundi-controltower-rgc",
    "key_id": "neomundi-rgc-2026-01",
    "confidentiality_class": "controlled",
    "retention_reference": "governance_logs:3d55da6a-8170-4480-a435-b0af0583a9fe"
  }
}

How your infrastructure verifies it

Only endpoints and primitives this repository actually documents or uses.

Public schema and verification keys — README §11.

curl https://api.neomundi.io/v1/rgc/schema

curl https://api.neomundi.io/v1/rgc/jwks

Obtain a contract for an existing observation — README §12 (requires an API key).

curl -X POST \
  "https://api.neomundi.io/v1/rgc/contracts/{request_id}" \
  -H "X-API-Key: YOUR_NEOMUNDI_API_KEY"

Adapted from consumer-reference/rgc_consumer_demo/verify.py in this repository — standard library + cryptography and pyjwt only, no NeoMundi internal code.

import hashlib, json, base64
import jwt
from cryptography.hazmat.primitives.asymmetric import ed25519
from cryptography.hazmat.primitives.serialization import Encoding, PublicFormat

def canonical_sha256(payload: dict) -> str:
    canonical = json.dumps(payload, sort_keys=True, separators=(",", ":"))
    return hashlib.sha256(canonical.encode("utf-8")).hexdigest()

def recompute_payload_hash(contract: dict) -> str:
    # integrity itself is excluded from its own hash
    sections = {k: contract[k] for k in
                ("identity", "provenance", "observation", "governance")}
    return canonical_sha256(sections)

def verify_signature(contract: dict, jwks: dict) -> bool:
    key_id = contract["integrity"]["key_id"]
    jwk = next(k for k in jwks["keys"] if k["kid"] == key_id)
    x = jwk["x"]
    raw = base64.urlsafe_b64decode(x + "=" * (-len(x) % 4))
    public_key = ed25519.Ed25519PublicKey.from_public_bytes(raw)
    pem = public_key.public_bytes(
        encoding=Encoding.PEM, format=PublicFormat.SubjectPublicKeyInfo
    )
    claims = jwt.decode(
        contract["integrity"]["signature"],
        pem,
        algorithms=["EdDSA"],
        options={"verify_aud": False},
    )
    return claims["payload_hash"] == contract["integrity"]["payload_hash"]

Runs live, in this page, against the example selected on the left — via SubtleCrypto (SHA-256 always; Ed25519 where the browser's WebCrypto implements it).

const canonical = JSON.stringify(sortedSections); // sort-keys, Python-compatible
const digest = await crypto.subtle.digest(
  "SHA-256", new TextEncoder().encode(canonical)
);
const recomputed = toHex(digest);
// recomputed === contract.integrity.payload_hash ?

const publicKey = await crypto.subtle.importKey(
  "jwk", jwk, { name: "Ed25519" }, true, ["verify"]
);
const valid = await crypto.subtle.verify(
  { name: "Ed25519" }, publicKey, signatureBytes, signingInput
);

CONTRACT RECEIVED

✓ Schema core structural checks passed — 6/6 (declared 0.1.0) Checked: required sections, model pattern, coverage range, execution_permission_changed=false. Not checked here: full JSON Schema Draft 2020-12 (all $ref / enum / format rules) — run the reference Python validator for that.

✓ SHA-256 MATCH (documented result — see README "Expected historical result") Precomputed. Enable JavaScript to recompute this fingerprint live, in your browser, from the raw contract.

✓ Signature VERIFIED (documented result — Ed25519/JWS) Precomputed. Enable JavaScript to verify this Ed25519/JWS signature live against the public JWKS.

✓ Key RESOLVED — key_id neomundi-rgc-2026-01 Found in the published JWKS (GET /v1/rgc/jwks).

→ Measurement available to consumer

→ CONTROL remains with your infrastructure

JavaScript is disabled: the Schema/SHA-256/Signature/Key lines above show the documented outcome for this exact signed example, not a live recomputation. Enable JavaScript to re-run every check in your own browser.

View JSON Schema View on GitHub Integration Guide

NeoMundi provides the measurement signal and its verifiable trace. It does not grant, revoke, or otherwise alter execution permission, and does not require access to your policy engine, thresholds, or enforcement logic.