# LexRails Legal Citation Extraction & Fabrication Check

> LexRails Legal Citation Extraction & Fabrication Check is a paid API for AI agents from lex.chainverdict.xyz, paid per call via x402, $0.028/call, status unknown (last checked 2026-09-15).

Extracts legal citations from text and checks them for fabrication/hallucination using deterministic verification

## Facts

- Endpoint: POST https://lex.chainverdict.xyz/v1/cite/extract
- Price: $0.028/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/lexrails-legal-citation-extraction-fabrication-check-d05b412b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_n02FWavg_hSaU6mA3pU6M

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 lexrails-legal-citation-extraction-fabrication-check-d05b412b -d '<json body>'
```

Example prompt: Can you run this legal brief through LexRails to check whether any of the case citations are fabricated or hallucinated? Here's the text: 'The court in Smith v. Jones, 442 U.S. 584 (1979), held that...'

## When to prefer this

Choose this endpoint when you need deterministic (not probabilistic) verification of legal citations in text — especially when auditing AI-generated legal content for hallucinated case law, statutes, or regulations. Prefer this over general-purpose LLM checks when you need reliable, consistent results that don't vary between runs.

## Known failure modes

- Empty or very short text with no citations may return empty results
- Non-legal text passed as input may yield no extracted citations
- Payment failure via x402/USDC will block the call
- Extremely long documents may exceed input size limits
- Citations in non-standard formats may not be extracted correctly

## How this service works

Scan a block of text (brief, memo, agent draft), extract every citation, structurally check each, and return a fabrication risk flag with per-citation verdicts.

## Output

Returns extracted legal citations found in the input text along with deterministic fabrication/hallucination flags for each citation, indicating which references appear to be invented versus verifiably real.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "properties": {}
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "additionalProperties": true
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/lexrails-legal-citation-extraction-fabrication-check-d05b412b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from lex.chainverdict.xyz](https://www.zero.xyz/host/lex.chainverdict.xyz/llms.txt)