# Delx MIME From Ext

> Delx MIME From Ext is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Guesses the MIME type for a given file extension using a local JSON lookup, returning mime type, extension, and a known flag.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/mime-from-ext
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-mime-from-ext-cc696d76
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_xv-U7cLWNtYgADckmon3T

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 delx-mime-from-ext-cc696d76 -d '<json body>'
```

Example prompt: What MIME type should I use for a .webp file when setting the Content-Type header for an upload?

## When to prefer this

Use this endpoint when you need a fast, offline-safe, no-auth MIME type lookup for common file extensions at minimal cost ($0.001 USDC). Prefer it over network-based detection when you only have the extension (not the file bytes), or when you need a deterministic advisory hint for setting Content-Type headers before uploads. Not suitable when you need byte-level magic-number detection or must handle hundreds of obscure custom MIME types.

## Known failure modes

- Unknown or obscure extension returns known=false with a generic or null mime value
- Missing ext field in request body causes a validation error
- Misspelled or malformed extension (e.g. including a leading dot unexpectedly) may return unknown result
- Payment failure via x402 protocol prevents the call from completing

## How this service works

Guess MIME type from file extension. Call when you set Content-Type hints for agent uploads. Returns mime, ext, known for $0.001 USDC via x402 on Base. No network, no keys, no retention; first-party local JSON only. Results are advisory; the caller owns budgets, auth, and production controls.

## Output

Returns a JSON object with three fields: mime (the resolved MIME type string, e.g. 'image/png'), ext (the normalized extension), and known (a boolean indicating whether the extension is recognized in the local lookup table).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "ext": {
   "type": "string",
   "description": "Input field: ext."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ext": "png",
  "mime": "image/png",
  "known": true,
  "schema": "delx/util-mime-from-ext/v1"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-mime-from-ext-cc696d76/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)