# Canon Fact-Verification API

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

Verifies a textual claim using fact-checking and academic research sources, returning a structured verdict

## Facts

- Endpoint: POST https://tascanon.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/canon-fact-verification-api-a94bcae3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_mTD6yDI3mQL_oSgWv-8F9

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-verification-api-a94bcae3 -d '<json body>'
```

Example prompt: Can you fact-check this claim for me in English: 'The Great Wall of China is visible from space with the naked eye'?

## When to prefer this

Use Canon when an AI agent needs to verify specific factual claims against academic and authoritative sources, especially for scientific, historical, or statistical assertions. Prefer this over general web search when you need a structured true/false verdict backed by research rather than a list of links.

## Known failure modes

- Missing required 'claim' field returns validation error
- Missing required 'lang' field returns validation error
- Unsupported language code may result in an error or degraded result
- Payment failure (insufficient USDC) returns HTTP 402
- Ambiguous or overly short claims may yield low-confidence results
- Network timeout for complex multi-source lookups

## 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 field indicating whether the claim was successfully processed and verified; in practice expected to also carry verdict details about whether the claim holds up against academic and factual sources.

## Example request

```json
{
 "lang": "en",
 "claim": "The Great Wall of China is visible from space with the naked eye"
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "lang",
  "claim"
 ],
 "properties": {
  "lang": {
   "type": "string"
  },
  "claim": {
   "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-verification-api-a94bcae3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from tascanon.orbonomy.xyz](https://www.zero.xyz/host/tascanon.orbonomy.xyz/llms.txt)