Kingsfield Connect the Judge
The Judge for Legal AI

Every legal citation,
adjudicated.

Your AI writes the brief. Kingsfield rules on whether each citation survives. A cloud judge any AI tool can call over MCP, with a corpus of the whole US primary-law surface behind it. Client PII is stripped on your own machine before anything leaves. The PII Tokenizer removes it first; a fail-closed firewall at the judge's door rejects anything PII-shaped as a backstop.

Connect the Judge See how it works
Audit Capsule · Verdict cap.v1:9f3c4ab7
Reject.
21 CFR §541.101(a) · Pinpoint authority does not support proposition

"Manufacturers of dietary supplements must submit a Pre-Market Notification at least 75 days before introducing a new ingredient, per 21 CFR §541.101(a)."

2026-05-25 · 19:47 UTC Ed25519 · signed
Fed + 50 states of US primary law
1.36M case-law opinions indexed
Verdicts Accept, Reject, Inconclusive
400 case precision bench every module passes
Practiced alongside the cloud-LLM stack firms already trust
Harvey CoCounsel Lexis+ AI Westlaw Precision Spellbook Hebbia Robin AI EvenUp Paxton Harvey CoCounsel Lexis+ AI Westlaw Precision Spellbook Hebbia Robin AI EvenUp Paxton
§ II · The Split

Kingsfield Adjudicates
PII Tokenizer Secures

Kingsfield ships as two halves of a single trust boundary, each with one job. Kingsfield adjudicates: the judge and the full corpus are hosted once, so no firm carries the hardware. The PII Tokenizer secures: the PII map is held on your own machine, so no client identifier ever leaves it.

Hosted · kingsfield.ai
The Judge
MCP server · BYO-LLM · per-module entitlements

The full primary-law corpus and the judge model, hosted once and reachable as an MCP server by any AI tool you already use. It adjudicates citations. It never generates, and a fail-closed PII firewall at its door turns away anything that looks like a client identifier.

Cloud-hosted PII firewall Per citation Audit Capsule signed
+
Local · your machine
PII Tokenizer
Purpose-built application · your machine · free with a seat

A dedicated application, engineered in-house by WalkerNash Development to protect privileged client information. It runs on the lawyer's own computer, strips client PII before any egress, holds the token-to-PII map locally, and restores the client's identity only on a passing verdict draft. The cloud holds no map, so detokenization can only ever happen locally, never in the cloud.

Local-only map Egress gate 31-pattern scan Free
§ III Why Now

Generative legal AI changed the brief.
The bar hasn't changed the standard.

Mata v. Avianca. Park v. Kim. Garner v. Kadince. Al-Hamim v. Star Hearthstone. The judicial record on AI-fabricated citations is accumulating, the bar associations are catching up, and the courts are not interested in your vendor's marketing copy. Three structural gaps every legal-AI tool you use today has not closed.

i.
Privilege

Cloud LLMs sit inside your privileged work as a sub-processor.

Every prompt passes through a vendor's logging, abuse-monitoring, and possibly its training pipeline. The privilege analysis is unresolved at best, hostile at worst.

KINGSFIELD →

Two gates keep PII off the cloud: the PII Tokenizer on your own machine strips it before egress, and a fail-closed firewall rejects it at the judge's door. The judge rules on tokens. The PII map never leaves your desk.

ii.
Hallucination

Self-check is not adjudication. The generator and the checker share a brain.

"We use multi-model verification" reads as marketing, not as a contract. Correlated failure modes across foundation models mean self-check misses the failures that matter most.

KINGSFIELD →

Per-citation adjudication against the sealed corpus. ACCEPT / REJECT / INCONCLUSIVE with a 100/100 contract on the fabrication class.

iii.
Context Rot

Long context degrades reasoning. The Chroma 2024 study quantified it.

Even on simple lookup tasks, LLM accuracy falls as the context window fills. Long briefs and discovery dumps are exactly where the model is least reliable, and exactly where firms rely on it most.

KINGSFIELD →

Bounded-context judge. One proposition, one cite, one ruling. The window the model sees is sized for the verdict, not the brief.

§ IV The Mechanism

A companion. Not a substitute.
Tokenize PII. Adjudicate. Detok.

Kingsfield does not write your brief. It rules on the citations the brief depends on. You keep your cloud-LLM relationships, your keys, and your existing prompt workflow. The PII boundary opens and closes on your own machine.

01.

Tokenize, then generate.

The local PII Tokenizer strips client PII and holds the map on your machine. Your AI — Harvey, CoCounsel, Lexis+, Claude, GPT, any of them — drafts on the tokenized text. An egress gate shows you the outbound payload before anything leaves.

Local · Your LLM · Egress Gate
→
02.

Kingsfield adjudicates.

The tokenized draft reaches kingsfield.ai over MCP. A fail-closed PII firewall scans first and rejects anything PII-shaped. Then every citation is resolved against the corpus and ruled on, one cite at a time. A verdict per cite, signed and hash-chained.

Cloud · PII Firewall · Ed25519
→
03.

Detokenize and ship.

The cloud holds no map, so the names can only come back here. On a PASS, your machine restores the PII into the work product. The signed Audit Capsule travels with the brief as your audit trail. On a REJECT, your AI redrafts and the cite goes back through.

Local Detok · Audit Capsule · Court-Ready
Notice

Client PII transmitted to any legal-AI platform upstream of Kingsfield egresses to that platform before Kingsfield receives it. Kingsfield tokenizes all inbound content as a condition of adjudication, for the indemnification of Kingsfield.AI and its parent, WalkerNash Development LLC; such tokenization does not cure disclosure already made to upstream processors. Tokenization is offered at no charge, but the firm must affirmatively elect it and maintain its data in protected status. The firm is the sole party liable for the protection of client PII. SOC 2 and like attestations are limited assurances of process, not guarantees of confidentiality.

§ V Three Verdicts

Three verdicts. No hedging.
Kingsfield rules on every citation.

No "confidence scores." No "probably correct." The judge rules on what the LLM put before it: does the cited authority actually support the proposition asserted? Three verdicts, each with a binding precision contract.

✓
Accept.
29 USC §207(a)(1) · FLSA

The cited statute directly imposes the duty asserted.

"FLSA §7(a)(1) imposes the 40-hour overtime threshold the proposition invokes. Authority and proposition align in full."

✕
Reject.
21 CFR §541.101(a) · FDA

The cited subsection does not support the asserted duty.

"Definitions clause. The 75-day pre-market notification duty asserted is found at 21 USC §350b, not in the cited regulatory subsection."

?
Inconclusive.
42 USC §1395mm(c)(8) · Medicare

Pinpoint authority is not present in licensed corpus.

"Medicare module not licensed at this firm. The judge declines to rule rather than fabricate. Acquire the module or escalate to senior review."

§ VI The Audit Capsule

Every verdict is signed.
Every Audit Capsule is PII-free.

The Audit Capsule is the firm's portable defensibility artifact. Hash-chained to the prior verdict, signed by the cloud judge's key, byte-identical to CPS v1.0. It records an opaque document id, the verdict, and content hashes — never a client name. The audit trail is PII-free by construction.

Audit Capsule cap.v1:9f3c4ab7e2c5…d18a
Reject.
Document cjd_8f21a0c7  · opaque id · no party names
Module / Corpus FDA · v0.9.4 · 218,000 records · 12 Parts
Authority Cited 21 CFR §541.101(a)
Issued 2026-05-25 · 19:47:11 UTC
Proposition "Manufacturers of dietary supplements must submit a Pre-Market Notification to the Secretary at least 75 days before introducing a new ingredient, per 21 CFR §541.101(a)."
Cited Text For the purposes of this part, the term "new dietary ingredient" means a dietary ingredient that was not marketed in the United States before October 15, 1994, and does not include any dietary ingredient which was marketed in the United States before October 15, 1994.
Ruling The cited subsection is a definitions clause. It establishes what the term "new dietary ingredient" means; it does not impose a 75-day pre-market notification duty on manufacturers. The asserted duty is at 21 USC §350b, not in the cited regulatory subsection. Verdict: Reject.
Hash Chain priorsha3-256:7b4e02a9c1f3…d4a2
payloadsha3-256:9f3c4ab7e2c5…d18a
siged25519:vC8x3KQp9aRn…tEY7v
Signed By K Kingsfield Cloud Judge · kingsfield.ai
tenant t_4471 · PII firewall: clean
§ VII Trust Posture

The math is the artifact.
Not an auditor's letter.

Kingsfield does not pursue SOC 2, ISO 27001, or HITRUST attestation. Those reports are a paid opinion about a vendor that handles your data — and Kingsfield never receives any. WalkerNash will sign a DPA; its scope is near-empty by design, because there is no client PII for the cloud to process.

The PII map never leaves your machine.

The local PII Tokenizer strips client identifiers and keeps the token-to-PII map on your own computer. A lawyer-confirmed egress gate shows the outbound payload and sends nothing until you confirm — the backstop for free-typed PII the patterns miss.

Local map · egress gate

A fail-closed firewall at the judge's door.

The cloud judge is default-deny: a submission must pass a PII scan to be ruled on. Structured identifiers — SSN, EIN, account, DOB, email, phone — are a hard reject. Names are cross-referenced against the cited authority. It returns the categories, never the offending text.

Default-deny · REJECTED_PII_DETECTED

Detokenization is local-only.

The cloud holds no token-to-PII map, so the names can only be restored on your machine, on a clean verdict. Detok never appears in the cloud audit chain. The judge and your own AI both stay blind to the client's identity.

No cloud map · 31-pattern scan

No per-tenant data. Nothing to breach.

The corpus is public law, identical for every firm. No matters, no documents, no PII are stored in the cloud — a tenant is an auth identity and a usage counter. The one durable record is the PII-free Audit Capsule chain. There is no client data at rest to lose.

Opaque doc-ids · near-empty DPA
§ VIII Practice Areas

License only what you practice.

Each module is a JWT entitlement on your seat: a corpus, a judge contract, a coverage scope-set. Add or drop them per practice area. The shared case-law layer is bundled with any module.

Federal · one inclusive module · all 15 practice areas
Regulatory

FDA & Life Sciences

Food, drug, device, and biologics regulation; FDA enforcement, guidance, and warning letters.

Labor

Employment & Labor

Wage and hour, discrimination, leave, benefits, and workplace safety.

Tax

Federal Tax

Income, corporate, partnership, and excise tax; IRS rulings and Treasury regulations.

IP

Intellectual Property

Patent, trademark, copyright, and trade secret; the PTO and the Federal Circuit.

Transactional

Securities & M&A

Securities offerings, disclosure, public M&A, and deal regulation.

Competition

Antitrust

Mergers, monopolization, restraints of trade, and enforcement.

Financial

Banking & Finance

Bank regulation, lending, payments, and consumer finance.

Restructuring

Bankruptcy

Chapter 7, 11, and 13; restructuring and creditors' rights.

Regulatory

Environmental

Clean Air and Water, CERCLA, RCRA, permitting, and enforcement.

Procurement

Government Contracts

Federal procurement, FAR/DFARS, bid protests, and compliance.

Regulatory

Healthcare

Medicare and Medicaid, fraud and abuse, HIPAA, and provider regulation.

Immigration

Immigration

Employment- and family-based immigration, removal, and compliance.

Trade

International Trade

Customs, tariffs, sanctions, export controls, and trade remedies.

Privacy

Privacy & Data

Data protection, breach response, consumer privacy, and transfers.

Regulatory

Telecom

Communications regulation, spectrum, broadband, and FCC enforcement.

Bundled
Shared Case-Law Layer
SCOTUS, the Federal Circuit, and Caselaw Access Project opinions — 1.36M and growing. Bundled with every module; no standalone license.
State · one module per state · all practice areas inclusive
CA California 18 practice areas
Civil litigation · Criminal defense · Family law · Community property · Estate planning · Trust & estate litigation · Real estate · Landlord/tenant · Personal injury · Insurance defense · Workers' comp · Small business · State tax · State employment · CCPA privacy · PAGA · CEQA · Cannabis
NY New York 17 practice areas
Civil litigation · Commercial Division · Criminal defense · Family law · Estate planning · Trust & estate litigation · Real estate · RPAPL · Landlord/tenant · Rent regulation · Personal injury · Insurance defense · Workers' comp · Small business · State tax · State employment · DFS financial
TX Texas 17 practice areas
Civil litigation · Criminal defense · Family law · Estate planning · Trust & estate litigation · Real estate · Homestead · Construction lien · Landlord/tenant · Personal injury · Insurance defense · Workers' comp · Small business · State tax · State employment · Oil & gas · Agricultural
FL Florida 17 practice areas
Civil litigation · Criminal defense · Family law · Estate planning · Trust & estate litigation · Real estate · Foreign RE · Homestead · Condo · Landlord/tenant · Personal injury · Insurance defense · Workers' comp · Small business · State tax · State employment · Assisted living
IL Illinois 16 practice areas
Civil litigation · Criminal defense · Family law · Estate planning · Trust code · Trust & estate litigation · Real estate · Landlord/tenant · Personal injury · Insurance defense · Workers' comp · Small business · State tax · Cook County tax · State employment · BIPA
Coverage is building to full-corpus depth across every practice area. A module ships only when it passes its 400-case precision bench.
§ IX · The Pairing

Harvey generates.
Kingsfield decides.

You keep the cloud-LLM stack your firm already pays for. Kingsfield runs alongside it as the verification layer your clients are starting to ask about and your bar association is starting to require.

Whichever generator your firm already pays for
Harvey
Cloud · GPT/Claude
Drafts memos, briefs, due-diligence reports across the firm's documents.
CoCounsel
Cloud · Thomson Reuters
Westlaw-grounded research, deposition prep, contract review.
Spellbook
Cloud · Word add-in
Transactional drafting and redlining inside Microsoft Word.
Lexis+ AI
Cloud · LexisNexis
Shepard's-grounded summarization, drafting, research.
Westlaw Precision
Cloud · Thomson Reuters
KeyCite-grounded research and headnote-aware retrieval.
raw Claude · GPT
Cloud · BYO
Direct frontier-model access for firms doing in-house tooling.
flows through
K
Kingsfield
The verification layer

Adjudicates every citation produced by any generator above. Pass / Fail / Inconclusive, per citation, from a cloud judge any of them can call over MCP. PII is tokenized before it ever leaves your machine. Signs each verdict, hash-chains the Audit Capsule, travels with the work product.

Cloud · MCP Per Citation Audit Capsule Signed Per Module
§ IX.a · Without Kingsfield
What Harvey alone delivers.
  • ✕Citations are generated, not adjudicated. The same model that drafted the brief is the one that "checked" it. Self-check is not verification.
  • ✕Client PII enters a multi-party cloud pipeline. 14 named infrastructure layers per the Pandey diagram. SOC 2 attests one vendor's controls, not the sub-processors that touch the bytes.
  • ✕No portable defensibility artifact. If a citation is challenged 18 months later, the firm has the email thread, not a signed verdict chain.
  • ✕Hallucinated citations land in client work product. Benchmarked vendor hallucination rates run 0.2–17% depending on task. Kingsfield's reject rate of 14.3% on generated cites is what those numbers look like when somebody is actually counting.
  • ✕Audit trail lives in the vendor's logs. Discoverable, jurisdictionally complicated, and not under the firm's control.
§ IX.b · With Kingsfield
What Kingsfield rules.
  • ✓Every citation is independently adjudicated. Different model, different corpus, different incentive. Pass / Fail / Inconclusive from a cloud judge, against the authoritative primary-law corpus.
  • ✓PII never reaches the cloud. Tokenized on your machine, rejected at the judge's door by a fail-closed firewall. The Pandey 14 layers still run; they receive tokens, not client names.
  • ✓Every verdict is a signed Audit Capsule. SHA3-256 hash chain + Ed25519 signature. Opaque doc-id, PII-free, ~4 KB, byte-identical to CPS v1.0. Travels with the brief.
  • ✓Hallucinations get caught before they ship. A bad citation gets a Reject verdict with the reason on record. The firm fixes it before the brief leaves the office, not after opposing counsel does.
  • ✓The DPA you sign is near-empty by design. No matters, no PII, no client data at rest in the cloud. The chain is the math, not the auditor's letter.
§ X · Pricing

Bring your own AI.
Pay for the verdict.

One seat price for everyone. $99 a month includes a module, 500 verdicts, the case-law layer, and the free PII Tokenizer. Add modules at $30 each. BYO-LLM on every call. The same deal for a solo and a 200-lawyer firm — we don't discount enterprise.

The Seat
Everything a lawyer needs to run a defensible practice. The same for a solo and a 200-lawyer firm.
$99
per seat / month
Billed per attorney. No platform fee, no hardware, no minimums, no annual lock-in.
  • One module included — Federal (all 15 practice areas) or any one state, all-inclusive
  • 500 verdicts / seat / month — the averaged mix covers the typical practice with room to spare
  • Shared case-law layer — 1.36M opinions, bundled
  • Free local PII Tokenizer, every seat
  • BYO-LLM — call the judge from any MCP client
  • Signed Audit Capsule chain
Connect the Judge →

+ $30 / mo Add a module

A module is a whole scope, licensed inclusive: Federal (all 15 practice areas) or a state (every practice area in CA, NY, TX, FL, or IL). Stack as many as you practice in, at $30 / module / seat / month. No bundles to negotiate, no count to game.

Equal footing One price, every firm

A solo pays the same per seat as a 200-lawyer firm. We don't discount enterprise. Boutiques shouldn't subsidize the big firms' negotiating leverage — the deal is the deal for everyone.

The math Why $99

Your generator costs ~$200 a seat and hallucinates roughly 1 in 5 cites (Stanford RegLab, 2024). The judge that makes every one defensible — and does in seconds what a manual cite-check costs you ~$50 of your own time — is $99.

Past 500 verdicts in a month? Prepaid packs top you up at $0.49 each — no overage surprises, no auto-upgrade.
The Local PII Tokenizer

Free to all subscribers.

The PII Tokenizer is a purpose-built application WalkerNash Development engineered in-house to protect privileged client information. It runs on the lawyer's own computer, strips PII before egress, holds the token-to-PII map locally, and detokenizes on a clean pass verdict. It is free with a seat because it is the discipline that keeps client data off the cloud — we would rather you never have the switch turned off.

FORMPurpose-built desktop application
RUNS ONYour computer · Win / macOS / Linux
SCAN31-pattern · fail-closed
GATELawyer-confirmed egress
MAPLocal-only · never uploaded
DETOKLocal · on clean pass verdict
PRICEFree
§ XI Common Questions

What firms ask first.

If the question is not here, send it to the intake. We respond to every one in under 48 hours.

Does Kingsfield replace Harvey, CoCounsel, or Lexis+?
No. Kingsfield is a companion verification layer. You keep your existing cloud-LLM stack and your firm's BYO-LLM relationship with whichever generator you prefer. Kingsfield rules on what the generator produces. The two are designed to be used together: the generator drafts, Kingsfield adjudicates.
Does my client's PII go to the cloud?
No. Two independent gates stop it. The PII Tokenizer on your own machine strips PII before anything leaves, and a lawyer-confirmed egress gate shows you the payload first. Then a fail-closed firewall at Kingsfield's door rejects any submission that still looks like a client identifier. Kingsfield holds no token-to-PII map, so detokenization can only happen back on your machine.
How does Kingsfield connect to my AI tools?
Kingsfield is an MCP server at kingsfield.ai. Any MCP-capable platform — Claude, Cursor, Cowork, a cloud SaaS adapter, your own tooling — calls it the same way it calls any other tool. There is no migration and no model swap. You keep your generator; you add Kingsfield.
Why no SOC 2 / ISO 27001 / HITRUST?
Those reports are a paid auditor's point-in-time opinion that a cloud vendor met controls it chose for itself. They carry no force of law, and they don't change the fact that your client's data still left your hands. Kingsfield never receives that data — it is tokenized before egress and rejected at the door if it is not. There is no PII at rest to attest. We will sign a DPA, and its scope is near-empty by design. The math is the artifact, not a paid auditor's letter.
What if I accidentally send raw PII in a prompt?
That is exactly what the two backstops are for. The lawyer-confirmed egress gate is your last look before anything leaves your machine. If something slips through, the cloud firewall is default-deny: it rejects the submission with the PII categories and positions, never echoing the offending text, and nothing is logged. Kingsfield rules on tokens or it does not rule at all.
Is the Audit Capsule actually admissible in court?
The Audit Capsule is a portable, signed, hash-chained artifact conforming byte-identical to the upstream CPS v1.0 specification. It carries an opaque document id and content hashes — never a party name. Admissibility in any specific proceeding is the court's call, but the Audit Capsule is the artifact your evidence custodian would produce — auditable, tamper-evident, self-describing, and PII-free.

Every brief faces
Kingsfield.

No demo. No deck. No hardware. Point your AI at the judge over MCP and download the free PII Tokenizer.

Connect the Judge