# File Hash Verifier

> File Hash Verifier is a paid API for AI agents from x402.forgemesh.io, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Fetches a remote file by URL and returns its cryptographic hash (SHA-256, SHA-512, SHA-1, or MD5) to verify it matches a published checksum before use.

## Facts

- Endpoint: POST https://x402.forgemesh.io/file-hash-verifier
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/file-hash-verifier-9d95ba78
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_e9GjsdxikfElMTOBM1M9Y

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 file-hash-verifier-9d95ba78 -d '<json body>'
```

Example prompt: Can you fetch https://releases.example.com/myapp-v2.3.0.tar.gz and compute its SHA-256 so I can confirm it matches the checksum the project published?

## When to prefer this

Use this endpoint when an AI agent needs to verify the integrity of a remotely hosted file before trusting, installing, or executing it — especially for packages, binaries, ML models, or release artifacts. Prefer it over computing hashes locally when the agent does not have direct file system access and needs to validate a public URL's content against a known checksum as a supply-chain safety step.

## Known failure modes

- File URL is unreachable or returns a non-200 status — error indicating fetch failure
- File exceeds 50MB limit — rejection with size error
- Invalid or unsupported algorithm specified — error with supported algorithm list
- URL points to a redirect loop or private/internal address — blocked fetch
- Network timeout fetching large files — timeout error

## How this service works

Fetches a public file URL, up to 50MB, and returns its SHA-256, SHA-512, SHA-1, or MD5 digest so you can confirm a download matches its published checksum before trusting it. A supply-chain safety step for agents pulling packages, models, or binaries from the open web.

## Output

Returns the cryptographic digest of the remote file using the requested algorithm (SHA-256 by default, or SHA-512, SHA-1, MD5), allowing the caller to compare against a known-good published checksum. Supports files up to 50MB.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string"
  },
  "algorithm": {
   "type": "string",
   "description": "sha256 default"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "hex": "eefffad4e662b2821b1aab5957d4dcc60ac6e19fd5523ec59dad6d29deac64e1",
  "bytes": 53647,
  "algorithm": "sha256"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/file-hash-verifier-9d95ba78/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.forgemesh.io](https://www.zero.xyz/host/x402.forgemesh.io/llms.txt)