# Claim Grounding Pro Deep Research

> Claim Grounding Pro Deep Research is a paid API for AI agents from claim-grounding.prospectintel.workers.dev, paid per call via x402, $15/call, status unknown (last checked 2026-10-17).

Verifies factual claims in text against authoritative sources (Wikipedia, Wikidata, Google News, Europe PMC, FRED, SEC EDGAR) and returns a structured verdict per claim

## Facts

- Endpoint: POST https://claim-grounding.prospectintel.workers.dev/v1/deep_research/pro?utm_source=zero.xyz
- Price: $15/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-17
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/claim-grounding-pro-deep-research-0ae3eccc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JowccCvVx1LPoVhhVYNYO

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 claim-grounding-pro-deep-research-0ae3eccc -d '<json body>'
```

Example prompt: Can you fact-check this claim for me: 'The Federal Reserve raised interest rates seven times in 2022' — run it through deep research grounding and tell me if it's supported, contradicted, or outdated based on FRED and news sources?

## When to prefer this

Choose this endpoint when an AI agent needs authoritative, multi-source fact verification covering biomedical (PubMed), financial (FRED, SEC EDGAR), encyclopedic (Wikipedia, Wikidata), and news (Google News) domains in a single call. It is especially valuable for grounding LLM-generated text before publication, auditing research summaries, or flagging hallucinations. Prefer it over generic web search when you need a structured, machine-readable verdict with source provenance rather than raw search results.

## Known failure modes

- Returns 400 if confirmed: true is missing from the request body — nothing is charged
- Insufficient evidence verdict when no authoritative source addresses the claim
- Outdated verdict if claim was once true but sources reflect changed facts
- Mixed verdict when sources conflict with each other
- Polling may be needed if status is 'queued' — results are not always synchronous
- Malformed or ambiguous claim text may produce low-confidence or insufficient_evidence results

## How this service works

Pay-per-call claim checks for AI agents. Sources: Wikipedia, Wikidata, Google News, Europe PMC (PubMed), FRED and SEC EDGAR. USDC on Base via x402 (Coinbase CDP facilitator). No API key. Every checked claim returns verdict: supported | contradicted | outdated | mixed | insufficient_evidence, plus status_detail and legacy_verdict (pre-1.2.0 value: supported | contradicted | not_found | conflict).

## Output

An async job object with a job_id and a polling URL for the full result. The receipt includes each parsed claim with its claim_id and grounding_required flag, priced_usd ($15), and created_at timestamp. When polled, each claim resolves to a verdict (supported, contradicted, outdated, mixed, or insufficient_evidence), a status_detail explanation, and a legacy_verdict for backward compatibility.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "text": {
   "type": "string"
  },
  "claim": {
   "type": "object",
   "properties": {
    "text": {
     "type": "string"
    }
   }
  },
  "answer": {
   "type": "string",
   "description": "Text whose claims should be researched."
  },
  "claim_ids": {
   "type": "array",
   "items": {
    "type": "string"
   }
  },
  "confirmed": {
   "const": true,
   "description": "Required. Without confirmed: true the call returns 400 and nothing is charged."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "mode": "fast",
  "poll": "GET /v1/jobs/job_8c1d2e3f4a5b6c7d (free)",
  "claims": [],
  "job_id": "job_8c1d2e3f4a5b6c7d",
  "status": "queued",
  "receipt": {
   "claims": [
    {
     "text": "Paris is the capital of France",
     "claim_id": "clm_3f9a1c2b4d5e6f70",
     "grounding_required": true
    }
   ],
   "job_id": "job_8c1d2e3f4a5b6c7d",
   "created_at": "2026-10-10T12:00:00.000Z",
   "priced_usd": 15
  },
  "next_actions": []
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/claim-grounding-pro-deep-research-0ae3eccc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from claim-grounding.prospectintel.workers.dev](https://www.zero.xyz/host/claim-grounding.prospectintel.workers.dev/llms.txt)