# Canon Fact-Check API

> Canon Fact-Check API is a paid API for AI agents from v0-canon.orbonomy.xyz, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-15).

Verifies factual claims and searches academic papers and journals for AI agents using a natural language query

## Facts

- Endpoint: POST https://v0-canon.orbonomy.xyz/api/factcheck
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/canon-fact-check-api-8aaa0549
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uOUe8zbE6anZvWR-H7uVx

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 canon-fact-check-api-8aaa0549 -d '<json body>'
```

Example prompt: Can you fact-check this for me: 'Drinking eight glasses of water per day is scientifically required for good health' — search academic journals and tell me whether it holds up?

## When to prefer this

Choose this endpoint when an AI agent needs to verify a factual claim or find academic/peer-reviewed sources to support or refute an assertion — especially in research, journalism, or content validation workflows where a small per-call cost ($0.05 USDC) is acceptable and authoritative sourcing matters.

## Known failure modes

- Missing required 'query' field returns a validation error
- Query too vague or ambiguous may return low-confidence or empty results
- Payment failure (USDC not sent or insufficient) triggers 402 response before processing
- Service unavailable returns non-200 status with no result body
- Query in unsupported language may return no matching academic sources

## How this service works

Fact-checking and academic research for AI agents. Verify claims, search papers, explore journals. USDC on Base.

## Output

A JSON object with a success boolean and (implicitly) fact-check or research results for the submitted query, including verification of the claim against academic or authoritative sources.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "query"
 ],
 "properties": {
  "query": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "success": {
   "type": "boolean"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/canon-fact-check-api-8aaa0549/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from v0-canon.orbonomy.xyz](https://www.zero.xyz/host/v0-canon.orbonomy.xyz/llms.txt)