---
title: "Fact-Check — free"
method: POST
path: "/v1/ai/fact-check"
tags: ["ai"]
---

# Fact-Check — free

`POST /v1/ai/fact-check`

## Request

- Base URL: `https://x402.asterpay.io`
- URL: `https://x402.asterpay.io/v1/ai/fact-check`
- Auth: none required

Source-bounded fact-check. Verify a claim against provided source text. Does NOT search the web. Free tier (no payment required).

## Request body

- object
  - `claim` string, required: Factual claim to verify (10-2000 chars)
  - `source` string, required: Source text to verify against (50-15000 chars)

## Response `200`

Fact-check result

- object
  - `verdict` 'supported' | 'contradicted' | 'unverifiable', required
  - `confidence` number, required
  - `evidence` string, required
  - `summary` string, required

---

[API](https://skmtc.dev/asterpay/apis/asterpay-data-api.md) · [All operations](https://skmtc.dev/asterpay/apis/asterpay-data-api/llms.txt) · [OpenAPI document](https://skmtc.dev/asterpay/apis/asterpay-data-api/revisions/97b4ab464b3b?raw)