# Groundcheck Claim Grounding & Citation Attestation

> Groundcheck Claim Grounding & Citation Attestation is a paid API for AI agents from groundcheck.seiche.info, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-13).

Verifies factual claims in a text document against live web sources, returning machine-verified verdicts (supported/refuted/unverified), confidence scores, and cited sources for each claim.

## Facts

- Endpoint: POST https://groundcheck.seiche.info/check
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/groundcheck-claim-grounding-citation-attestation-0d6534ed
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_rarBbSFnLNpOIewVVvZYt

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 groundcheck-claim-grounding-citation-attestation-0d6534ed -d '<json body>'
```

Example prompt: Check the facts in this paragraph and tell me which claims are supported, refuted, or unverified — and show me the sources: 'The Eiffel Tower was completed in 1889 and stands 330 meters tall. It was originally intended to be dismantled after 20 years.' Verify up to 5 claims.

## When to prefer this

Choose this endpoint when an AI agent must produce citable, verifiably grounded text — especially for research pipelines, compliance checks, or citation-locked content generation where hallucination is unacceptable. Prefer it over general-purpose search when you need a structured machine-readable verdict (supported/refuted/unverified) per claim with source attribution, rather than raw search results. Ideal for agents that have already generated text and need post-hoc attestation before delivery.

## Known failure modes

- Text contains no verifiable factual claims — returns empty claims array or unverified verdicts
- max_claims exceeds allowed maximum of 20 — returns validation error
- Live source lookup fails or times out — claim may return as unverified with low confidence
- Text is too ambiguous or opinion-based — claims returned as unverified with note of insufficient evidence
- Conflicting evidence across sources — endpoint refuses to guess and returns unverified with conflicting sources listed

## How this service works

Claim grounding and citation attestation for AI agents: verified enrichment that adds a veracity field to text. Each factual claim is grounded against live web sources (Wikipedia + world news) and returned with a machine-verified verdict (supported/refuted/unverified), a confidence score, and cited sources. Refuses to guess on conflicting evidence. Built for research agents that must cite, citation-locked content, and compliance checks.

## Output

The agent receives a structured response for each extracted factual claim, including: a verdict label (supported, refuted, or unverified), a confidence score (0–1), and a list of cited live sources (Wikipedia pages or news articles) that ground or contradict the claim. Claims with conflicting evidence are returned as unverified rather than guessed.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "text": {
   "type": "string",
   "minLength": 1,
   "description": "Document whose factual claims to verify"
  },
  "max_claims": {
   "type": "integer",
   "maximum": 20,
   "minimum": 1
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "report": [
   {
    "claim": "The Eiffel Tower was completed in 1889.",
    "verdict": "supported",
    "rationale": "sources support and none refute",
    "confidence": 0.83
   }
  ],
  "backend": "wikipedia+gdelt",
  "checked": 2,
  "classifier": "free-llm-router"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/groundcheck-claim-grounding-citation-attestation-0d6534ed/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from groundcheck.seiche.info](https://www.zero.xyz/host/groundcheck.seiche.info/llms.txt)