# ArtifactGuard Web Claim Verifier

> ArtifactGuard Web Claim Verifier is a paid API for AI agents from artifactguard-kl4hfo6j2q-as.a.run.app, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-14).

Verifies AI-generated claims against a specified public HTTPS web source and returns a cryptographically signed evidence receipt

## Facts

- Endpoint: POST https://artifactguard-kl4hfo6j2q-as.a.run.app/v1/evidence/web
- 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/artifactguard-web-claim-verifier-4782b3d5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ydjnfhgK0fLe5u0boo0XH

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 artifactguard-web-claim-verifier-4782b3d5 -d '<json body>'
```

Example prompt: Check whether the claim 'OpenAI was founded in 2015' is actually supported by the content at https://en.wikipedia.org/wiki/OpenAI, and give me a signed evidence receipt I can use to prove it.

## When to prefer this

Choose this endpoint when you need cryptographic, auditable proof that an AI-generated claim is grounded in a specific public web page — not just a summary or scrape. It is ideal for compliance workflows, AI output auditing, research validation, and any scenario where a tamper-evident signed receipt is required. Prefer the companion PDF endpoint when the source is a PDF document rather than a web page.

## Known failure modes

- Target URL is not publicly accessible or requires authentication — returns error indicating unreachable source
- URL returns non-HTML content (e.g. binary file) — endpoint may fail or return unexpected results
- Claim is too vague or ambiguous to match against source content — low-confidence or inconclusive result
- Target page contains prompt injection or obfuscation — may affect extraction quality
- Network timeout fetching the remote URL — returns timeout error
- Invalid or malformed URL input — returns validation error

## How this service works

Verify AI-generated claims against a public HTTPS web source and receive a signed evidence receipt.

## Output

A cryptographically signed evidence receipt indicating whether the submitted claim is supported, partially supported, or contradicted by the fetched web page content, along with relevant excerpts from the source and a tamper-evident signature for audit purposes.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/artifactguard-web-claim-verifier-4782b3d5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from artifactguard-kl4hfo6j2q-as.a.run.app](https://www.zero.xyz/host/artifactguard-kl4hfo6j2q-as.a.run.app/llms.txt)