# Veritas Fact Verification API

> Veritas Fact Verification API is a paid API for AI agents from veritas.orbonomy.xyz, paid per call via x402, $0.1/call, status unknown (last checked 2026-09-15).

Verifies the truthfulness of a text claim against multiple sources, returning a verdict, confidence score, and explanation

## Facts

- Endpoint: POST https://veritas.orbonomy.xyz/api/verify
- Price: $0.1/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/veritas-fact-verification-api-a0cf3a66
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_F4Iit5aYZyjGz6RvX1pbv

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 veritas-fact-verification-api-a0cf3a66 -d '<json body>'
```

Example prompt: Can you fact-check this claim for me: 'The Great Wall of China is visible from space with the naked eye' — I want to know if it's true, how confident you are, and what sources back that up.

## When to prefer this

Use Veritas when you need a multi-source, confidence-scored fact verdict on a specific claim — especially when you need an explanation and traceable sources, not just a binary true/false from a single reference. Prefer this over general web search when structured fact-checking output with confidence scoring is required.

## Known failure modes

- Empty or missing claim field returns a 400 validation error
- Claim too ambiguous or short for sources to evaluate — low confidence score or unverified verdict
- Unsupported language code results in error or fallback to default language
- External source lookup failure may reduce confidence or return partial results
- Rate limiting or payment failure returns 402 if USDC payment is not processed

## How this service works

Multi-source fact verification API

## Output

Returns a boolean success flag, a verdict string (e.g. true/false/unverified), a confidence score (0–1), a plain-language explanation of the finding, and an array of source URLs used to reach the verdict.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "claim"
 ],
 "properties": {
  "lang": {
   "type": "string",
   "description": "Language code"
  },
  "claim": {
   "type": "string",
   "description": "The claim to verify"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "success"
 ],
 "properties": {
  "sources": {
   "type": "array",
   "items": {
    "type": "string"
   }
  },
  "success": {
   "type": "boolean"
  },
  "verdict": {
   "type": "string"
  },
  "confidence": {
   "type": "number"
  },
  "explanation": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/veritas-fact-verification-api-a0cf3a66/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from veritas.orbonomy.xyz](https://www.zero.xyz/host/veritas.orbonomy.xyz/llms.txt)