00Platform — under the hood

The audit trail is the
product.

Verum is not a chatbot. It is five layered subsystems — input modes, probabilistic extraction, deterministic gate, decorative LLM commentary, and four output bridges — connected by a typed audit trail that the medical director can override at any layer.

01Five-layer architecture

Probabilistic on top.
Deterministic at the gate.

The single layer that uses no LLM is the layer that produces the verdict. The decorative LLM calls in § 04 are advisory only — they cannot change the answer.

§ 01
INPUT
IO
Free-text note
Paste · type
Structured form
23-field tri-state
Voice
Groq Whisper · Voxtral
§ 02
EXTRACT
PROBABILISTIC
Clinical-fact extractor
LLM · 14 typed spans
Verbatim source quotes
Per-fact provenance
Per-fact confidence
0..1 scalar
§ 03
GATE
DETERMINISTIC
Rule projection
Facts × ontology
Borderline tolerance
ε = max(2, T × 0.25)
Verdict + audit
APPROVE · PEND · DENY
§ 04
DECORATE
DECORATIVE
Advisor commentary
LLM · non-blocking
Soft signals
Patterns the rules miss
Counterfactuals
What would flip this?
§ 05
OUTPUT
IO
Verdict card + PDF
Operator override surface
Bridge → Appeal · Root-cause
F1 · F2
Bridge → CDS Hooks · Eligibility
F3 · F4
02BRIDGE · image evidence into the gate

The bridge between
AI image evidence + deterministic policy.

The dictated radiology report often hedges on documentation the gate needs. BRIDGE lets the UM reviewer have Verum · Vision read the image, attest the findings, and promote them into the deterministic gate's fact bank — flipping verdicts on cases where the report missed what the image showed. BRIDGE-extended ontology rules carry a brass “BRIDGE” pill in the cited-rules list so the reader always knows which rules derive from core CMS policy vs the AI-evidence ontology layer. Append-only audit on the Decision; every promotion reversible.

§ 01
CASE ARRIVES
IO
PA case with attached imaging
Lumbar MRI · CXR · cervical · etc.
Dictated report — hedged
"narrowing, etiology unclear"
Gate runs on text alone
→ PEND on documentation
§ 02
VERUM · VISION READS
PROBABILISTIC
Reviewer clicks Read this image
Drawer slides in from right
MedGemma 4B foundation
Spine prompt · 3-8s warm · 12-14 min cold
Structured findings stream in
factKey · value · visualEvidence · confidence
§ 03
REVIEWER ATTESTS
ATTESTATION
High-confidence findings pre-checked
conf > 0.7 default-on
Reviewer toggles + clicks Promote
attestation chain captured
ImagePromotionAudit on Decision
reviewer · model · ts · verbatim quote
§ 04
GATE RE-DERIVES
DETERMINISTIC
BRIDGE-extended rules fire MET
imaging-confirmed-stenosis-severity · etc.
decide() runs in pure code
No LLM in the verdict path
PEND → APPROVE
Verdict pill + reasoning suffix · downstream cite
03Ontology lattice

4 procedures × 3 payers × 2 versions.

Two flagship ontologies encoded verbatim from real public policy. Eight synthetic tuples flagged explicitly in their sourceDocument field — no hidden mocks.

Policy version · 202412 cells
ProcedureMedicareCommercialMedicaid
Lumbar MRI
SYN · marked
SYN · marked
SYN · marked
Cervical MRI
SYN · marked
SYN · marked
SYN · marked
Brain MRI
SYN · marked
SYN · marked
SYN · marked
CT Abdomen/Pelvis
SYN · marked
SYN · marked
SYN · marked
Policy version · 202612 cells
ProcedureMedicareCommercialMedicaid
Lumbar MRI
REAL · LCD L34220
SYN · marked
SYN · marked
Cervical MRI
REAL · LCD L34220
SYN · marked
SYN · marked
Brain MRI
SYN · marked
SYN · marked
SYN · marked
CT Abdomen/Pelvis
SYN · marked
SYN · marked
SYN · marked
Flagship REAL — verbatim from cited policy
Synthetic — flagged in sourceDocument
04Model-portable provider lattice

Five providers.
Forty-eight curated models.

No vendor lock-in. Click a provider below — the extract agent re-routes live, the latency and cost-per-million-token pills recompute, and the architecture stays identical. Switching a real workspace agent works the same way.

Live routing · click a provider
EXTRACT AGENTClinical fact extractorGRQGroqus-eastOROpenRoutermultiGGGoogleus / euMSMistraleuNIMNVIDIA NIMself-host
Provider
Groq
P50 latency
410 ms
Per million tok
$0.60
Zero-data-retention
yes
Switch agent provider · no code change
P · 01 · fastest
Groq
0
curated models
P · 02 · broadest
OpenRouter
0
curated models
P · 03 · reasoning
Google
0
curated models
P · 04 · eu
Mistral
0
curated models
P · 05 · enterprise
NVIDIA NIM
0
curated models
05Standards we speak

EDI · CDS Hooks · FHIR.

Round-trip fluency in the data formats payers actually use. Generators and parsers for each — proves "we know about EDI" vs "we work with EDI."

S · 01

EDI · X12N 5010

  • 270 · Eligibility request
  • 271 · Eligibility response
  • 835 · Remittance advice
S · 02

CDS Hooks · 1.0

  • Discovery + invocation (spec-compliant)
  • order-sign · prior-auth-prefetch
  • order-select · appropriate-use-criteria
S · 03

FHIR · R4 + CRD-aligned

  • PlanDefinition + Library export
  • CQL emitter with fact-type bindings
  • ValueSet posture via meta.tag
06Public-policy provenance
CMS · LCD L34220

Lumbar Spinal Imaging — Medicare LCD

The federal coverage determination. Read verbatim into the lumbar-Medicare ontology. Source of authority for §-by-§ rule encoding.

PRIMARY
Aetna · CPB 0236

Imaging of the Spine — Aetna Clinical Policy Bulletin

The commercial-payer policy used as a triangulation anchor for the lumbar and cervical Medicare ontologies. Where CMS is sparse, Aetna fills with operational criteria.

PRIMARY
Carelon · 2025-11-15

Imaging of the Spine — Carelon RBM

A third independent source for cross-validation. When all three agreed, the criterion was promoted to flagship REAL.

CROSS-VALIDATION
See the engine work

Layered architecture.
Run it end to end.