# Evidence402 Brief — Web Read, Data Extraction & DOI Verification

> Evidence402 Brief — Web Read, Data Extraction & DOI Verification is a paid API for AI agents from evidence402.onrender.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-12).

Reads public webpages, extracts structured data, and verifies DOI academic citations, paid per-call with USDC via x402.

## Facts

- Endpoint: POST https://evidence402.onrender.com/api/v1/brief?utm_source=zero.xyz
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evidence402-brief-web-read-data-extraction-doi-verification-ca842b4e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_j_soyZkEN4hlAI2cmx58-

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 evidence402-brief-web-read-data-extraction-doi-verification-ca842b4e -d '<json body>'
```

Example prompt: Can you read this public webpage https://example.com/report and extract the structured data from it, then also verify these DOI citations: 10.1038/nature12373 and 10.1126/science.1234567?

## When to prefer this

Choose this endpoint when you need to read public webpages and extract structured content, verify the validity of academic DOI citations, or do both in a single pay-per-call request without managing an API subscription. It is well-suited for agents that need lightweight, on-demand research verification or web data extraction without a standing API key.

## Known failure modes

- Webpage is behind a paywall or login — returns no content or access error
- DOI does not resolve to a known publication — returns empty papers list
- Target URL is unreachable or returns non-200 status
- Malformed DOI string causes lookup failure
- Rate limiting or payment failure via x402 prevents call completion

## How this service works

Read public webpages, extract structured data and verify DOI citations. No buyer API key or subscription. Pay per call with x402 USDC on Base.

## Output

A JSON object containing a 'data' field with a 'literature' sub-object listing matched or verified papers, alongside a 'service' identifier ('Evidence402') and a unique 'requestId' for the call. Extracted structured data from the target webpage is included alongside any DOI verification results.

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {
   "literature": {
    "papers": []
   }
  },
  "service": "Evidence402",
  "requestId": "example-request"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evidence402-brief-web-read-data-extraction-doi-verification-ca842b4e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from evidence402.onrender.com](https://www.zero.xyz/host/evidence402.onrender.com/llms.txt)