# Veridictum Legal — Single Citation Verifier

> Veridictum Legal — Single Citation Verifier is a paid API for AI agents from veridictum.legal, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-12).

Verifies a single legal citation against a 14.2M-case corpus (CourtListener), detecting whether the case name matches the reporter citation or reveals a hallucinated reference.

## Facts

- Endpoint: POST https://veridictum.legal/api/v1/agent/verify?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/veridictum-legal-single-citation-verifier-e1013279
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Ig1wyYHF_0HQ1dJDxaixD

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability veridictum-legal-single-citation-verifier-e1013279 -d '<json body>'
```

Example prompt: Can you verify that 'Roe v. Wade, 410 U.S. 113 (1973)' is a real citation and that the case name actually matches that reporter volume and page?

## When to prefer this

Choose this endpoint when you need to verify a single legal citation with high deterministic accuracy — especially when you have a full citation including the case name and need to detect name-reporter mismatches (the hallucination signature). Prefer the batch sibling endpoint when verifying multiple citations at once. This endpoint is purpose-built for detecting AI-hallucinated legal references and is backed by a 14.2M-case corpus with no LLM in the verification path, making it more reliable than asking an LLM to self-verify its own citations.

## Known failure modes

- Bare citation without case name returns name_match='not_checked' — mismatch detection is unavailable
- not_found is a valid finding, not a transient error — retrying will return the same result
- Citations outside the 14.2M-case corpus may return not_found even if they exist
- Malformed citation strings (missing volume or page) may fail regex parsing
- status=suspicious is itself the hallucination signal and should be treated as a finding, not an error

## How this service works

Verify one legal citation. Body: {"citation": "<string>"} - full ("Miranda v. Arizona, 384 U.S. 436 (1966)") or bare ("384 U.S. 436"); the case name enables mismatch detection. Deterministic: regex plus cache / local corpus / CourtListener, no LLM in the path. status=verified (name confirmed), suspicious (reporter resolves to a DIFFERENT case - the fabrication signature), or not_found. verified=false is a finding, not an error: do not retry. Only verified results are cached.

## Output

Returns a status field of 'verified' (case name confirmed to match the reporter citation), 'suspicious' (the reporter citation resolves to a DIFFERENT case — the hallucination signature), or 'not_found' (citation does not exist in the corpus). Also returns a name_match field ('confirmed', 'mismatch', or 'not_checked' for bare citations). A non-verified result is a definitive finding — agents should not retry.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "citation": {
   "type": "string",
   "minLength": 1,
   "description": "One legal citation. Full (\"Miranda v. Arizona, 384 U.S. 436 (1966)\") or bare (\"384 U.S. 436\"). Supplying the case name is what enables mismatch detection; a bare citation can only be confirmed to exist and returns name_match='not_checked'."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/veridictum-legal-single-citation-verifier-e1013279/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from veridictum.legal](https://www.zero.xyz/host/veridictum.legal/llms.txt)