# 402utils MIME Type Detector

> 402utils MIME Type Detector is a paid API for AI agents from 402utils.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Detects a file's true MIME type from its magic-number byte signature, returning type, extension, confidence, category, and executable flag

## Facts

- Endpoint: POST https://402utils.com/v1/mime-detect
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/402utils-mime-type-detector-f7a4dded
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Tna-6iVGLZOkxqLm5can_

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 402utils-mime-type-detector-f7a4dded -d '<json body>'
```

Example prompt: I just received an uploaded file with a .jpg extension but I'm not sure it's really an image — can you check its actual MIME type from the raw bytes and tell me if it's an executable or something dangerous?

## When to prefer this

Use this endpoint when you need to determine a file's true type based on its actual binary content rather than trusting its declared extension or Content-Type header. Ideal for security-sensitive file upload pipelines, content validation, and detecting disguised executables. Covers a wide range of formats including images, OOXML/OpenDocument, archives, audio/video, fonts, and executables.

## Known failure modes

- File exceeds 10 MB limit — request rejected
- Unrecognized byte signature — low confidence or unknown MIME returned
- Malformed base64 input — parse error
- Empty body sent — no bytes to analyze
- Network timeout for large files near the size limit

## How this service works

Detect a file's true MIME type from its magic-number byte signature — not from a declared extension or Content-Type. Send the raw bytes (≤10 MB) as the body, or JSON { bytes: base64 }. Returns {mime, extension, confidence, description, category, executable}. Covers images, documents (incl. OOXML/OpenDocument), archives, audio/video, fonts and executables (which are flagged). Security check for file pipelines. Not a barcode/QR reader.

## Output

Returns a JSON object with fields: mime (the detected MIME type string), extension (canonical file extension), confidence (detection confidence score), description (human-readable file type description), category (broad category such as image/document/archive), and executable (boolean flag indicating if the file is an executable, useful for security screening)

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "bytes": {
   "type": "string",
   "description": "The file's raw bytes as base64 (alternative to sending them raw)."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/402utils-mime-type-detector-f7a4dded/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 402utils.com](https://www.zero.xyz/host/402utils.com/llms.txt)