strix-verify 0.2.0

Independent verification of Strix governance evidence records. Ed25519 + SHA-256 only. No Strix tooling or account required. Public source at github.com/strixgov/strix.

strix-verify

Independent verification of Strix governance evidence records.

No Strix tooling, SDK, or account required. Uses only standard cryptographic primitives (Ed25519, SHA-256) via the Python cryptography library.

strix-verify is offline-safe. Save the JWKS once, ship it with the evidence, verify on an air-gapped machine. No callbacks. No telemetry. No Strix server required at runtime.

Proof Readiness Level 4.5 — Cryptographically Signed + Externally Verifiable

Public source: github.com/strixgov/strix PyPI: pypi.org/project/strix-verify

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Installation

pip install strix-verify

Or from source:

cd python/strix-verify
pip install -e .

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Quick Start

from strix_verify import verify_evidence

result = verify_evidence(
    evidence_id=123,
    proof_base="https://strix.example.com",  # your Strix deployment
    jwks_base="https://strixgov.com",        # canonical JWKS surface
)

print(result.signature_valid)                          # SignatureStatus.VERIFIED
print(result.hash_valid)                               # True
print(result.compliance.article12_tamper_resistant)    # True
print(result.compliance.article14_human_oversight)     # True
print(result.compliance.article28_provider_obligations) # True

proof_base is required — there is no default. The verifier is neutral across Strix deployments and never carries a hardcoded host URL.

Async

import asyncio
from strix_verify import fetch_evidence_async, verify_evidence_record

async def main():
    record = await fetch_evidence_async(123, proof_base="https://strix.example.com")
    result = verify_evidence_record(record, jwks_base="https://strixgov.com")
    return result

asyncio.run(main())

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Verification Flow

1. Fetch — Retrieve evidence record from the Strix proof API
2. Reconstruct — Build canonical 13-field payload (locked field order)
3. Fetch key — Resolve Ed25519 public key from JWKS endpoint
4. Verify signature — Ed25519 signature over canonical payload
5. Verify hash — SHA-256 hash of canonical payload
6. Derive compliance flags — EU AI Act flags derived from outcomes (never asserted)
7. Return — VerificationResult with all outcomes

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Two-Layer Verification Model

Layer 1 — Cryptographic Validity (signature_valid)

"Was this record produced by the holder of the Strix signing key?"

Status	Meaning
VERIFIED	Valid Ed25519 signature from a known key
LEGACY_UNSIGNED	Pre-signing record (migration before 0039)
UNVERIFIABLE_KEY	Signing key ID not found in JWKS or extra_keys
COMPLIANCE_VIOLATION	Signature present but invalid
ERROR	Network or unexpected failure

Layer 2 — Deployment Context (environment_match, tenant_match)

"Is this record appropriate for this deployment context?"

Optional checks against stored record fields. Per SE-14, verification reads environment and tenantId from the stored evidence record — never from environment variables. This prevents false failures when a production record is verified in a development context.

result = verify_evidence(
    evidence_id=123,
    expected_environment="production",   # checks stored record field
    expected_tenant_id="tenant-abc",     # checks stored record field
)
print(result.environment_match)  # True/False/None
print(result.tenant_match)       # True/False/None

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Verifying a Local Record

If you already have the evidence record dict (from a database, file, etc.):

from strix_verify import verify_evidence_record

result = verify_evidence_record(
    record,
    jwks_base="https://strixgov.com",
)

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Verifying Offline (Air-Gapped)

For audit environments that cannot reach the internet, pre-fetch the JWKS once, save it next to the evidence, and verify with no network access at runtime:

import json
from strix_verify import verify_evidence_record

with open("evidence-2026-04-19.json") as f:
    record = json.load(f)

with open("jwks-snapshot-2026-04.json") as f:
    extra_keys = json.load(f)["keys"]

result = verify_evidence_record(
    record,
    extra_keys=extra_keys,
    jwks_base="https://unused.invalid",  # never reached when key is in extra_keys
)

When the signing key is already present in extra_keys, jwks_base is never contacted. The verifier resolves the key from the pre-fetched JWK list and does the full cryptographic check locally.

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Key Rotation Support

Historical signing keys can be provided to verify older records after key rotation:

import json, os

extra_keys = json.loads(os.environ.get("STRIX_SIGNING_JWKS_EXTRA", "[]"))

result = verify_evidence(
    evidence_id=123,
    extra_keys=extra_keys,
)

Key ID format: strix-{env}-{YYYY-MM} (e.g., strix-prod-2026-04). EU AI Act compliance requires a minimum 2-year key retention period.

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EU AI Act Compliance Flags

Compliance flags are derived from verification outcomes — never read from stored fields (invariant CI-5). Altering the regulatoryContext block in a signed record invalidates the Ed25519 signature.

Flag	Derived From
article12_tamper_resistant	hash_valid AND chain_valid AND signature_valid == VERIFIED
article14_human_oversight	signature_present (actor fields cryptographically bound)
article28_provider_obligations	signature_valid == VERIFIED (evidence from known key)

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Canonical Payload Schema

The 13-field locked-order payload that is signed and hashed:

schemaVersion (always "1")
evidenceId
evidenceHash
proofChainHash
capabilityId
action
actorId
actorRole
createdAt
signingKeyId
environment
tenantId
regulatoryContext { complianceMode, euAiActArticle12, euAiActArticle14, euAiActArticle28 }

Warning: Reordering these fields invalidates all existing signatures. This schema is locked and versioned. See tests/test_payload.py::test_golden_vector for the canonical serialization canary.

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JWKS Endpoint

Public keys are served at:

GET https://strixgov.com/.well-known/strix-jwks.json
GET https://strixgov.com/.well-known/strix-jwks.json?kid=strix-prod-2026-04

The endpoint follows RFC 7517. Each key is an OKP/Ed25519 JWK with a kid in strix-{env}-{YYYY-MM} format.

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Development

# Install with dev dependencies
pip install -e ".[dev]"

# Run tests
pytest

# Run tests with coverage
pytest --cov=strix_verify --cov-report=term-missing

# Lint
ruff check src/ tests/

# Type check
mypy src/

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Architecture Notes

• No Strix SDK dependency — pure Python + cryptography + httpx
• Ed25519 SPKI DER construction matches the TypeScript implementation exactly: 12-byte header 302a300506032b6570032100 + 32 raw key bytes
• Never raises on bad signatures — verify_signature() returns False
• Sync and async HTTP clients available for all network operations

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License

MIT — see LICENSE.