# Crucible Claim Research & Fact-Check

> Crucible Claim Research & Fact-Check is a paid API for AI agents from crucible.unitynodes.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-14).

Verifies a factual claim against provided evidence text, returning a verdict, confidence score, risk score, cited sources, and per-claim support breakdown.

## Facts

- Endpoint: POST https://crucible.unitynodes.com/research/claim
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/crucible-claim-research-fact-check-26e11237
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_X4zL5o_vZyL2ISL8Q-gG1

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 crucible-claim-research-fact-check-26e11237 -d '<json body>'
```

Example prompt: Fact-check this claim for me: 'Ethereum completed the Merge in September 2022' — here's the evidence text from a recent article: 'The Ethereum network transitioned from proof-of-work to proof-of-stake on September 15, 2022, reducing energy consumption by over 99%.' Give me a verdict with confidence and any cited sources.

## When to prefer this

Choose this endpoint when you need a structured, confidence-scored, source-cited verdict on a specific claim checked against provided evidence text — especially in Web3 or research contexts where auditability (content hash) and cited sourcing matter. Prefer over generic LLM fact-checking when you need a risk score, per-claim evidence breakdown, and cryptographic content hash for verification. Best when you already have evidence text and want a formal verdict rather than open-ended research.

## Known failure modes

- Missing required 'claim' or 'evidence' field returns a 400 validation error
- Insufficient or vague evidence may yield low confidence score and inconclusive verdict
- Payment failure via x402 protocol returns 402 status before processing
- Very long evidence text may time out or be truncated
- Sources array may be empty if no external sources are resolved from the evidence

## How this service works

Pay-per-call Web3 agent services: wallet, token and agent security audits; token prices, depeg checks and portfolio valuation; cited fact-checking and source research.

## Output

Returns a verdict string (e.g. supported/refuted/inconclusive), a confidence score (0–1), a risk score, an array of cited source objects (url, name, hash), a per-claim evidence breakdown with support ratings and source indices, and a content hash for auditability. Also echoes the original claim.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "claim",
  "evidence"
 ],
 "properties": {
  "claim": {
   "type": "string",
   "description": "Claim to verify"
  },
  "evidence": {
   "type": "string",
   "description": "Evidence text to check the claim against"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "cost": {
   "type": "number"
  },
  "data": {
   "type": "object",
   "properties": {
    "claim": {
     "type": "string"
    },
    "verdict": {
     "type": "string"
    }
   }
  },
  "sources": {
   "type": "array",
   "items": {
    "type": "object",
    "properties": {
     "url": {
      "type": "string"
     },
     "hash": {
      "type": "string"
     },
     "name": {
      "type": "string"
     }
    }
   }
  },
  "evidence": {
   "type": "array",
   "items": {
    "type": "object",
    "properties": {
     "claim": {
      "type": "string"
     },
     "support": {
      "type": "string"
     },
     "sourceIndex": {
      "type": "number"
     }
    }
   }
  },
  "riskScore": {
   "type": "number"
  },
  "confidence": {
   "type": "number"
  },
  "contentHash": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/crucible-claim-research-fact-check-26e11237/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from crucible.unitynodes.com](https://www.zero.xyz/host/crucible.unitynodes.com/llms.txt)