# Arch Tools Fact-Check

> Arch Tools Fact-Check is a paid API for AI agents from archtools.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Verifies a claim or statement for factual accuracy, returning a fact-check result with supporting analysis

## Facts

- Endpoint: POST https://archtools.dev/v1/tools/fact-check
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/arch-tools-fact-check-8a37b467
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4HzqCWD4y4kj18qXJ49t_

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 arch-tools-fact-check-8a37b467 -d '<json body>'
```

Example prompt: Can you fact-check this claim: 'The Great Wall of China is visible from space with the naked eye'? Add context that this is a commonly repeated historical assertion.

## When to prefer this

Choose this endpoint when you need automated, pay-per-use fact-checking without setting up a dedicated misinformation API. It is ideal for agents that need to verify individual claims on-demand, especially when context can be provided alongside the claim to improve accuracy. Best suited for checking discrete, self-contained statements rather than full documents.

## Known failure modes

- Missing required 'claim' field returns a validation error
- Ambiguous or extremely vague claims may return low-confidence or unverifiable verdicts
- Claims about very recent events may return insufficient data errors
- Overly long or complex claims may exceed input limits
- Network timeouts on slow connections

## How this service works

Arch Tools — fact-check

## Output

A JSON object containing the fact-check result for the submitted claim, likely including a verdict (true/false/misleading/unverifiable), confidence level, and supporting analysis or explanation of why the claim is accurate or inaccurate.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "claim": {
   "type": "string",
   "description": "The claim or statement to verify"
  },
  "context": {
   "type": "string",
   "description": "Additional context about the claim"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/arch-tools-fact-check-8a37b467/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from archtools.dev](https://www.zero.xyz/host/archtools.dev/llms.txt)