# Sanity Claim Verification API

> Sanity Claim Verification API is a paid API for AI agents from sanity.wickedapi.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-10-29).

Verifies whether a given claim is true or false by checking it against supplied context or live web evidence.

## Facts

- Endpoint: POST https://sanity.wickedapi.com/check?utm_source=zero.xyz
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sanity-claim-verification-api-67b0470a
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fGP-7HZ4JthQVV_V1F71W

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 sanity-claim-verification-api-67b0470a -d '<json body>'
```

Example prompt: Can you fact-check this claim for me: 'The Eiffel Tower is taller than the Empire State Building' — check it against the web and tell me if it's true or false?

## When to prefer this

Use this endpoint when you need to fact-check a specific, discrete claim — especially when you can supply your own context document or want live web evidence to be fetched automatically. Prefer it over general-purpose LLM reasoning when you need a structured verdict with a confidence score and cited evidence, rather than an informal answer. It is particularly useful for content moderation pipelines, pre-publication review, or any agentic workflow where claims must be verified before acting on them.

## Known failure modes

- Claim is too ambiguous or broad for a definitive verdict
- Insufficient or conflicting web evidence leading to uncertain result
- Rate limit or payment failure if USDC balance is insufficient
- Claim contains no verifiable factual assertions (e.g. pure opinion)
- Live web evidence unavailable or blocked for certain topics

## How this service works

Verify a claim against supplied context or live web evidence.

## Output

Returns a verdict (true, false, or uncertain) on the submitted claim, along with a confidence score and references to the supporting or contradicting evidence used to reach the conclusion — either from the supplied context or from live web sources.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "mode": {
   "enum": [
    "grounded",
    "open"
   ],
   "type": "string"
  },
  "claim": {
   "type": "string"
  },
  "context": {
   "oneOf": [
    {
     "type": "string"
    },
    {
     "type": "array",
     "items": {
      "type": "string"
     }
    }
   ]
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sanity-claim-verification-api-67b0470a/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from sanity.wickedapi.com](https://www.zero.xyz/host/sanity.wickedapi.com/llms.txt)