USE CASE · AUDIT EVIDENCE & DEFENSIBLE PROGRAMS
Walk into the audit with the evidence already assembled.
Every screening and data query returns a dated, source-cited record signed to an append-only chain. When OCR, CMS, or a payer asks how you knew what you knew and when, the answer is an artifact — not a vendor statement.
Signed attestation per recordEd25519 witness chainPoint-in-time historyMethodology versioned
✓ No PHI✓ SOC 2 Type 1 in progress (Q3 2026)✓ Re-derivable offline✓ JSON · CSV · PDF
The enforcement reality
The audit is not whether you checked. It is whether you can prove it.
CMS Care Compare records in fines and 2,553 payment denials across 6,919 nursing facilities over a rolling three-year window. When enforcement lands, the question is not whether you ran a screen — it is whether you can produce the dated, sourced record of every check.
A screenshot or a spreadsheet cell does not survive that question. An attestation that names the source, the date, and the snapshot — and proves it was not altered afterward — does.
The developer pain
Reconstructing evidence months after the fact.
When the audit request arrives, teams scramble to reconstruct what a record said at decision time — but the source file has since changed, the join logic moved, and there is no log of the methodology in force back then. The evidence is rebuilt, not retrieved, and a rebuilt record is contestable.
An audit-pack export returns the period's records already joined, each with its snapshot date, methodology version, and chain reference. The evidence is retrieved exactly as it was held — there is nothing to reconstruct.
How it works
Four properties that make a record defensible.
When
Timestamp
Every query is logged with a UTC timestamp. The record shows the moment the check ran, not the moment you exported the report.
What
Source + snapshot
Each field names its source and the snapshot date it was read from — the exact upstream version, pinned and reproducible.
How
Methodology version
The methodology version is stamped at query time. The same version run later reproduces the same record, byte for byte.
Proof
Signed chain
Each record is signed to an Ed25519 witness chain with a public key, so its integrity is provable — and re-derivable offline by anyone.
Integration & workflow
One evidence trail. Two ways in.
Developers pull an audit pack over REST and re-derive the chain programmatically. Compliance teams assemble the pack for an audit period and attach the signed attestation.
GET /api/v1/audit-pack/export
curl "https://fonteum.com/api/v1/audit-pack/export?ccn=115001&format=json" \
-H "Accept: application/json"Response
{
"ccn": "115001",
"generated_at": "2026-06-17T14:02:11Z",
"sources_joined": 12,
"records": [
{
"field": "civil_money_penalty_total",
"value": "248500.00",
"_source": "CMS Care Compare — Nursing Home",
"_snapshot": "2026-05-01",
"_methodology": "audit-pack/v1",
"sha256": "9f2c…a17b"
}
],
"attestation": {
"chain_link_index": 142,
"public_key_url": "https://fonteum.com/.well-known/chain-public-key.json",
"verify_url": "https://fonteum.com/api/v1/chain/verify"
}
}Export joins every ingested federal source for a facility (CCN) or provider, in NDJSON, JSON, or CSV. The chain link is re-derivable via POST /api/v1/chain/verify — recompute the hashes from inputs alone, no DB access required.
- 01Define the program: which sources you screen and enrich against, and on what cadence.
- 02Every query is logged with a UTC timestamp, the source snapshot date, and the methodology version in force.
- 03For an audit period, assemble the audit pack: every relevant record joined, with per-field provenance.
- 04Attach the signed attestation — the chain link that proves the records were held, unaltered, on those dates.
- 05Hand the auditor the pack; they re-derive the chain offline to confirm integrity without trusting Fonteum.
Sample audit-evidence artifact
AUDIT PACK — EVIDENCE MANIFEST
Scope ............... CCN 115001 (single facility)
Generated (UTC) ..... 2026-06-17T14:02:11Z
Sources joined ...... 12 federal source families
Civil money penalty . $248,500.00 [CMS Care Compare · 2026-05-01]
Exclusion screen .... no match [OIG LEIE · 2026-06-01]
Methodology ......... audit-pack/v1
Chain link .......... index 142 (Ed25519 witness chain)
Public key .......... /.well-known/chain-public-key.json
Re-derive offline ... /api/v1/chain/verifyThe signed attestation links each record to an append-only chain. An auditor re-derives it offline against the public key — the integrity proof never asks them to trust Fonteum.
Proof — not logos
The evidence layer is itself auditable.
Methodology
Every methodology version is published and pinned per record, so an auditor can read exactly how the figure was derived.
Ed25519
Witness chain
An append-only signature chain with a public key. Records are signed as they are held; the chain proves the sequence was not edited.
100%
Public corrections
Every correction is logged publicly with a date. The defensibility comes from radical transparency, not from claiming we are never wrong.
Public-domain sources
All evidence draws on public federal records. No PHI, no scraped data, no proprietary black box an auditor cannot inspect.
“The artifact your compliance officer attaches to the response — not a vendor statement that something was checked.”
AUDIT EVIDENCE
Assemble the evidence pack before the audit asks for it.
Questions
Before the security questionnaire.
What makes this defensible in an audit?
Three things an auditor asks for: when the check ran, what source it ran against, and proof the record was not altered after the fact. Every Fonteum result carries a UTC timestamp, a named source with its snapshot date, a pinned methodology version, and a signature linking it to an append-only chain.
Can an auditor confirm the evidence without trusting Fonteum?
Yes. The attestation chain is an Ed25519 witness chain with a public key. An auditor can download a chain link and re-derive its hashes offline, then confirm one online linkage to the prior link. The integrity proof does not depend on taking our word for it.
What if a source changes after I pulled it?
The record is point-in-time. The snapshot date pins the exact version of the source you screened against, and the chain proves you held that result on that date. A later upstream change cannot retroactively alter or invalidate the evidence you assembled.
What is in an audit pack?
A facility- or provider-scoped export joining every relevant federal source — exclusion, penalty, deficiency, staffing, ownership — with per-field provenance, the methodology version, and the chain reference. Available as JSON, NDJSON, CSV, or a signed PDF artifact.
Is this a SOC 2 control?
Fonteum's SOC 2 Type 1 audit is in progress (target Q3 2026). The provenance and attestation layer maps to change-management and integrity controls, and the public correction log records every change. The audit pack is the evidence artifact your own controls can point to.
Go deeper
The provenance layer behind the evidence.
Solutions
All solutions — by use case & buyer →
Trust
Methodology & versioning →
Trust
Data provenance & the attestation chain →
Trust
Public corrections log →
Capability
Point-in-time snapshots →
Research
Nursing home penalties enforcement 2026 →
Use case
Exclusion & sanctions screening →
Use case
Credentialing & provider-data enrichment →
For compliance
Fonteum for compliance & risk teams →
FONTEUM · AUDIT EVIDENCE
Build a defensible program on public data only. No PHI.