# SourceCheck News - Article Fact Verification

> SourceCheck News - Article Fact Verification is a paid API for AI agents from sourcecheck-news.d-mueller.workers.dev, paid per call via x402, $0.16/call, status unknown (last checked 2026-09-15).

Verifies whether the main factual claims in a proposed news article are supported by the provided source texts

## Facts

- Endpoint: GET https://sourcecheck-news.d-mueller.workers.dev/api/verify
- Price: $0.16/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sourcecheck-news-d-mueller-workers-dev-0b9c39bd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yzH2NasaC0VlFxYugMFW-

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 sourcecheck-news-d-mueller-workers-dev-0b9c39bd
```

Example prompt: Can you verify the facts in this draft news article against these three source documents I'm providing — I need to know if the main claims in the article are actually supported by the sources?

## When to prefer this

Use this endpoint when you need to programmatically verify that factual claims in a news article draft are backed by specific source documents you already possess. Ideal for editorial workflows, automated fact-checking pipelines, or AI writing assistants that need to validate AI-generated or human-written news content against reference material before publication.

## Known failure modes

- Empty article text returns validation error
- No sources provided (minItems:1 not met) returns schema error
- Source objects missing required 'id' or 'text' fields cause rejection
- Very long article or sources may time out
- Payment failure (x402) returns 402 Payment Required
- Malformed JSON input returns 400 error

## How this service works

Verify whether the main factual claims in a proposed news article are supported by the provided source texts.

## Output

A structured assessment indicating whether the main factual claims found in the article are supported, partially supported, or unsupported by the provided source texts, likely with per-claim or overall verdicts referencing source IDs.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "article": {
   "type": "string",
   "minLength": 1
  },
  "sources": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "id",
     "text"
    ],
    "properties": {
     "id": {
      "type": "string"
     },
     "text": {
      "type": "string",
      "minLength": 1
     }
    },
    "additionalProperties": false
   },
   "maxItems": 3,
   "minItems": 1
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sourcecheck-news-d-mueller-workers-dev-0b9c39bd/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from sourcecheck-news.d-mueller.workers.dev](https://www.zero.xyz/host/sourcecheck-news.d-mueller.workers.dev/llms.txt)