What evidence exists?
Governance is only as good as the evidence it leaves behind. Nexus keeps a small set of artifact types — each hashed, each linked to the control, decision, or recommendation it supports — and seals decisions into an append-only hash chain that anyone can re-verify.
Evidence artifacts
Six synthetic artifacts. The hash shown is the real SHA-256 of the artifact's metadata; sensitivity is always governance metadata, never patient information.
| Artifact | Type | Recorded | Supports | Integrity |
|---|---|---|---|---|
| Model card · Sovereign clinical model 2026.06Capabilities, approved workloads, data classifications, residency, and the internal evaluation summary for the sovereign clinical model. | Model cardDEMO-EVD-001 | 2026-06-18 | DEMO-MDL-SOV-01DEMO-RCPT-0002 | sha256:1d05b83c54347954…governance metadata |
| AI inventory and risk ranking · v2Five AI systems inventoried and risk-ranked; mapped to GOV-01, GOV-02 and O. Reg. 51/26 program expectations. | Control mappingDEMO-EVD-002 | 2026-07-28 | GOV-01GOV-02DEMO-REC-001DEMO-REC-004 | sha256:34c1b9a28d69b240…governance metadata |
| Scribe vendor contract · residency clause extractReference to the contract clause naming Canadian hosting; sub-processor confirmation still outstanding. | Source referenceDEMO-EVD-003 | 2026-07-02 | DEMO-SYS-001DEMO-REC-002VEN-01 | sha256:6353d001398b592d…governance metadata |
| Policy decision record · PHI request blocked from external modelAlice decision BLOCK with reason PHI_REQUIRES_SOVEREIGN_EXECUTION; sovereign alternative offered and accepted. | Policy decisionDEMO-EVD-004 | 2026-08-27 | DEMO-RCPT-0001DEMO-POL-001 | sha256:cb584987561c26b8…governance metadata |
| Proxy block change record · consumer AI on clinical subnetsChange ticket, approval, and verification screenshot reference for the network block. | Remediation recordDEMO-EVD-005 | 2026-08-20 | DEMO-REC-001DEMO-RSK-001 | sha256:b7ca670e051b9f67…governance metadata |
| Clinician approval record · discharge summary draftNamed clinician approval captured on the Trust Receipt before the draft entered the record. | Approval recordDEMO-EVD-006 | 2026-08-27 | DEMO-RCPT-0002DEMO-REC-003CLIN-01 | sha256:68f5903d93ea9970…governance metadata |
Audit hash chain
Each event commits to the previous event's hash and to its own content. Editing, deleting, or reordering any event breaks every hash after it. The chain below was sealed at build time and re-verified when this page rendered.
Verification
PASS 9 events, every hash recomputed and every link checked.
Head hash
b8cf83c67726ad6ca096bfa9f27b148f32a6bf9745b7b642b3ba3d0fee7a0894
Chain digest
344c68fb129e83ae3852b40e72692d5626ef82f0ed893097035488c56a68cca4
One value that binds the whole chain, suitable for off-box anchoring.
- #0POLICY APPROVED · policy DEMO-POL-001May 12, 2026, 4:00 p.m. UTC · user · role:privacy-officerself 7c64343adc5f391aaf44… · prev 000000000000…
- #1POLICY APPROVED · policy DEMO-POL-002Jun 30, 2026, 6:20 p.m. UTC · user · role:cioself f95c9f9538bf3c7cab09… · prev 7c64343adc5f…
- #2ASSESSMENT FINALIZED · assessment DEMO-ASMT-002Aug 15, 2026, 7:05 p.m. UTC · operator · role:cyberchain-reviewerself 00400899c2bd7c77df20… · prev f95c9f9538bf…
- #3AI DECISION · trust-receipt DEMO-RCPT-0001Aug 27, 2026, 3:42 p.m. UTC · system · BLOCKself 853321c5cee02f6b27eb… · prev 00400899c2bd…
- #4AI DECISION · trust-receipt DEMO-RCPT-0002Aug 27, 2026, 3:44 p.m. UTC · system · ALLOWself 4e0c2eb0d989b7423cd2… · prev 853321c5cee0…
- #5HUMAN REVIEW APPROVED · trust-receipt DEMO-RCPT-0002Aug 27, 2026, 3:51 p.m. UTC · user · role:Attending physician, Internal Medicineself df2052810eedc7779c93… · prev 4e0c2eb0d989…
- #6AI DECISION · trust-receipt DEMO-RCPT-0003Aug 28, 2026, 9:12 a.m. UTC · system · REVIEW_REQUIREDself b129ae3f24c0b53ea096… · prev df2052810eed…
- #7AI DECISION · trust-receipt DEMO-RCPT-0004Aug 28, 2026, 11:03 a.m. UTC · system · ALLOWself 1369a5deaf7735c5bc58… · prev b129ae3f24c0…
- #8RECOMMENDATION CLOSED · recommendation DEMO-REC-003Aug 12, 2026, 8:00 p.m. UTC · user · role:cmioself b8cf83c67726ad6ca096… · prev 1369a5deaf77…
What tampering looks like
A copy of the chain with one field changed — the BLOCK on the first receipt rewritten to ALLOW — then re-verified. This runs live on every render of this page.
Honest status: the hash-chain module is a tested foundation. Persisting the chain to the production audit table with database-level immutability is an approval-gated integration step. This demo shows the mechanism on synthetic events; it is not a claim that every production event is chained today.
Ready to see your own organization?
Everything above is synthetic. Signing in shows your organization's own assessment, risks, policies, recommendations, and Trust Receipts. Access follows a confidential discussion and a signed NDA.
Every record on this page is synthetic and belongs to a fictional hospital. Nothing here is a customer, a patient, or a production measurement. The scoring, eligibility, and audit logic are the real Nexus engines running over the synthetic inputs.