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FonteumPublic-records evidence
CHAIN INTEGRITY

Snapshot-attestation coverage, disclosed.

This page reports the internal attestation rows and chain links that currently exist. Those counts can change as backfills run. No provenance fact currently links deterministically to a signature.

Live status
signed chain head snapshot (15 days ago)
head attestation digest (sha256)
b01b487e5c9a(expand)b01b487e5c9a8f4ffded8148b32b3b5bea788504c150311171118eda245f00d4
total links1497 links (including genesis)
signing key (ed25519)22:a1:d4:cb:dd:a4:2c:3e · fonteum-chain-2026-06-16
External timestamp anchor · initializing
latest OTS submission (12 days ago)
submitted digest (sha256)f950647f7eb1
stored proof records165

On July 12, 2026, independent validation found that 0 of 162 stored OpenTimestamps proofs validated against authentic Bitcoin-mainnet block headers. Fonteum therefore does not present any stored proof as externally confirmed. The database status is an internal operational field, not mainnet evidence. [corrected on 2026-07-12] Machine read: /api/v1/chain/anchors.

How the chain works

01

Snapshot taken

A captured source observation records source, date, row count, and a SHA-256 field. Historical attestations do not all hash complete source bytes; the inspection surface identifies the object each digest covers.

02

Snapshot signed

When an attestation row carries an Ed25519 signature, its recorded digest and signature can be checked with the published public key. That attests the signed object; it does not establish that every source row is signature-linked.

03

Snapshot chained

A snapshot attestation is in this chain only when a chain link references its attestation id. Newer unattached attestations are not chain members. Chain membership still does not create a deterministic signature relationship to provenance facts.

Inspect any snapshot

This endpoint currently returns a clearly labelled illustrative response shape; the field-level historical store required for a real snapshot diff is not live. Set an issued FONTEUM_API_KEY before trying the integration stub:

curl -s https://fonteum.com/api/v1/snapshots/diff \
  -H "Authorization: Bearer $FONTEUM_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "dataset": "nppes",
    "from_snapshot": "2026-04-01T00:00:00Z",
    "to_snapshot": "2026-05-01T00:00:00Z",
    "fields": ["taxonomy", "addresses"]
  }'

Response shape

{
  "dataset": "nppes",
  "from_snapshot": { "digest": "…", "signature": "…", "signing_key_fingerprint": "…" },
  "to_snapshot":   { "digest": "…", "signature": "…", "signing_key_fingerprint": "…" },
  "changes": [
    {
      "npi": "1234567890",
      "field": "taxonomy",
      "change_type": "modified",
      "before": { "value": "…", "provenance": { /* 14-tuple */ } },
      "after":  { "value": "…", "provenance": { /* 14-tuple */ } }
    }
  ],
  "summary": { "total_changes": 2, "added": 0, "removed": 0, "modified": 2 }
}

Full reference: /docs/api/snapshots-diff

Public signing key
4d00161d451385d6a6976175bfb13841b90975aebf9ac70f7d8c3e7e768be7e6
READY TO INSPECT

Inspect the evidence that exists.

Browse stored snapshot metadata and chain coverage. The snapshot-diff endpoint uses an issued key and is an illustrative integration stub, not row-history replay.

What’s on file, by the numbers

Platform snapshot · 2026-07-26

13.4Mproviders & companiesProviders, organizations, owners, and facilities on file
26.2Msource-linked factsSource-linked field facts in the dated platform snapshot
90sources with dataDistinct snapshot source IDs with at least one positive record count
79fresh sourcesDistinct source IDs whose latest positive-data snapshot falls within the preceding 45 days
111sources integratedActive registry rows; integration does not establish a load
13state Medicaid jurisdictionsDistinct states represented in the state-exclusions serving table

Integrated, with-data, and fresh-observation counts are separate. No platform-wide source-completeness count is published. Completeness is source-specific and must be evaluated against the named source's expected scope. State coverage is a separate jurisdiction measure.

Source authority is record-specific

Use the issuer named on the record.

Fonteum spans federal, state, and global public publishers. A source page or returned record identifies its issuer and dataset where that metadata is available. A platform registry count does not assign every page to one authority or establish loaded, fresh, or complete coverage.

Browse source records and their stated limitations →

Reproducible by design

Inspect the evidence each published figure actually supplies.

Source and date

Research pages expose the named public file and observation date where those fields are available. Source-file SHA-256 coverage is separate; facts do not currently link deterministically to signatures.

Available derivation

Studies with a retained release and committed derivation link the SQL or method used. Other studies state the evidence and reproduction limits they actually have.

Daily observations

Dated table row-count observations can detect local drift. They do not imply that an upstream publisher released or Fonteum ingested new data that day.

Named medical review

Reviewed by Jennifer Montecillo, MD, medical reviewer. Non-practicing medical reviewer.

Read the full provenance and attestation methodology →

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