Your AI drafts.
One fabricated citation is all it takes. The public sanctions database already runs 1,641 cases deep. Kingsfield rules on every cite before you file.
Keep the AI tools your firm already pays for. Kingsfield rules:
ACCEPT, REJECT, or INCONCLUSIVE, on every citation they produce.
Runs alongside the AI your firm already pays for
From 1,148 US court-sanctioned AI citation errors, 700 were clean enough to rule on. Kingsfield ruled 696 right.
Pick a citation to judge
25 real cases from the tested set. Click any one to watch Kingsfield rule, then open the full write-up.
The verdict appears here. Pick a citation on the left to watch Kingsfield rule.
Rule your AI draft
Run your AI-written brief through the full Kingsfield ruling: every citation checked for existence, every quote checked against the opinion, every proposition checked against the holding. You get back a signed Audit Capsule. Start with $50 in free credit. After that, top up your balance any time. Pay only for the citations we verify: failed or inconclusive cites need correction, $10 minimum per submission, no subscription.
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Verify your bar, get $50 in credit
Licensed attorneys only. We check your bar number against the public roster. Once you clear, we email your login, $50 of free credit, and your private link to the PII Shield. No card required to start.
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Install the PII Shield
The download link comes in your verification email, so the shield stays with verified attorneys. It strips client PII in your browser before any draft leaves your machine, so nothing identifiable reaches our server. Install it and the portal unlocks. Free but required.
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Submit your draft, get the ruling
Inside the portal you paste your AI-written brief. The full three-level ruling runs against the live corpus, then returns the verdict and a signed Audit Capsule for the file. You pay only for the citations that pass; failed and inconclusive cites need correction. Top up to keep going.
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Protect your client PII with other AI tools
Kingsfield offers the same PII Shield protection across other cloud AI tools as custom builds. Available on request.
Thanks.
When your $50 runs out, top up your balance to keep going. You pay only for the citations that pass — the same published rate for every attorney, billed to your client as a recoverable cost.
We don't hand the shield to just anyone. Once your bar credentials clear, your verification email from WalkerNash includes a private link to download and install the Kingsfield PII Shield. It strips client PII in your browser before any draft leaves your machine, so nothing identifiable reaches our server. Install it, and the portal opens.
Download link arrives in your verification emailThree ways AI gets it wrong.
Kingsfield rules on all three.
Damien Charlotin's AI Hallucination Cases Database catalogs real court cases where a lawyer was sanctioned for AI-generated citation errors. Kingsfield rules on US case law once a flagged citation is pulled out of the order into a clean, checkable claim. Here is how the full database narrows to the set we could test, and how Kingsfield ruled on it.
every country, real sanctions
the rest need other countries' corpora
real cites, verbatim quotes, holdings to verify
How Kingsfield ruled on the 700
case doesn't exist
ruled correctly · 100%
quote never written
ruled correctly · 100%
real case, wrong rule
ruled correctly · 96%
That is the whole 700: 504 fabricated cites + 92 fabricated-quote rows + 104 misstated-holding cases. Kingsfield ruled 696 of 700 correctly (99.4%): every cite and every quote, and 100 of 104 holdings. The 4 holding misses are topical over-accepts, where the opinion really is about the subject but does not establish the specific rule the brief claimed.
Honest scope: this measures Kingsfield's ruling layer given extracted claims, not an end-to-end "feed it a whole brief" production run. The 700 splits into three checks: a cite to a case that does not exist, a quote that was never written, and a real case cited for a holding it does not contain. The first two are clean by construction and run at 100%; misstated holdings is a judgment call, runs at 96% after our cite-kind routing fix, and is the layer we are still hardening. One quote row the database had mislabeled, a real quote from In re Innovatio, Kingsfield correctly accepted; we also dropped Will v. Michigan, 491 U.S. 58, tagged fabricated but a real Supreme Court decision Kingsfield ruled real. Hallucinated cases from the Charlotin database we could not pose cleanly (cites buried in PDFs, no recoverable quotes, ordinance cites not indexed) were excluded.
A companion to your AI.
Kingsfield does not write your brief. It rules on the citations the brief depends on, against the authoritative primary-law corpus, over MCP.
Independent adjudication
A different model, a different corpus, a different incentive than the one that drafted the brief. Self-check is not verification. Kingsfield rules from the outside.
PII never reaches the cloud
Client identifiers are tokenized on your own machine. A fail-closed firewall at the judge's door turns away anything PII-shaped before it can be read.
A verdict you can defend
Every ruling is a signed Audit Capsule: SHA3-256 hash chain plus an Ed25519 signature, roughly 4 KB, PII-free. It travels with the brief.
Three ways AI lies
A fabricated case, a fake quote, and a wrong holding are three different failures. Kingsfield runs all three. Tools that only check whether a cite exists miss the other two.
Keep your stack
Harvey, CoCounsel, Lexis+, Westlaw, Claude, GPT. Whatever drafts your work, Kingsfield reaches it as an MCP server. You keep your keys and your workflow.
Still good law
A real case can still be overruled. Kingsfield checks whether the authority is current, not just whether it once existed, and flags cites that no longer hold.
Kingsfield adjudicates.
Each has one job. The judge and the full corpus are hosted once, so no firm carries the hardware. Client identifiers are tokenized on your machine before anything is sent, so no client identifier ever leaves it.
The full primary-law corpus and the judge model, hosted once and reachable as an MCP server by any legal AI tool you already use. It adjudicates, never generates. A fail-closed firewall at the door turns away every client identifier.
A tool we built in-house to keep privileged client information off our server. The browser shield that gates the judge is free and required: it tokenizes each draft before it reaches us, so no client identifier ever arrives and the capsule comes back PII-free, with nothing to map back. Firms whose PII currently goes to other cloud AI tools in the clear can ask about a custom build that protects their whole workflow, including the return leg that restores the real identities from each tool's response locally, with the token-to-PII map never leaving your machine.
Toggle to see what leaves your machine. CLIENT_0001 is what Kingsfield rules on; it never sees the client, and the verdict capsule comes back PII-free, so nothing needs mapping back.
Pay only for the cites
We bill only on citations that pass. Failed and inconclusive cites need corrected resubmittals. $10 minimum per submission. No subscriptions, no seats, no enterprise discounts: the solo and the national firm pay the same published rate. Start with $50 in free credit, then bill each ruling to your client as a recoverable cost.
credit
- Pay only for cites that pass. Failed and inconclusive cites need correction
- $10 minimum per submission; a cite that passed already on a matter is never billed twice
- Full three-level ruling on every citation: existence, quote, proposition
- Signed Audit Capsule on every verdict
- Recoverable from your client as a disbursement, like a filing fee
- Client PII stripped in your browser before anything reaches us
Bill it to the client Recoverable cost
Each ruling is a cost you advance on the matter and itemize like a filing fee or a PACER charge. The client pays for the verification, so a clean draft costs your practice nothing net.
PII Shield Free · required
The shield that strips client PII in your browser is free and required, so nothing identifiable ever reaches our server. Firms that want the same protection across their other cloud AI tools can ask about a custom build.
Kingsfield is a citation-verification tool, not a law firm. It gives no legal advice and forms no attorney-client relationship. A pass is not a guarantee that a citation is correct or good law; you make the final decision on every result. See the Terms of use and Legal & limitations.
Put the judge in the loop.
Keep your AI. Add the layer your clients, your bar, and the courts are now asking about.
Judge a citation