> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mobileintelapi.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Authentication

> Send your API key in the X-API-Key header.

Every lookup needs your API key in the `X-API-Key` header, plus a real `User-Agent` header.

```bash theme={null}
curl "https://mobileintelapi.com/api/v1/verify?number=4169670000" \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "User-Agent: my-app/1.0"
```

A missing or wrong key returns `401`:

```json theme={null}
{ "detail": "invalid or missing X-API-Key" }
```

`GET /health` is the only endpoint that works without a key.

## Managing keys

* Create and revoke keys under **API keys** in your [account](https://mobileintelapi.com/app/).
* Use one key per app or workflow, so you can revoke one without breaking the others.
* A revoked key stops working within about 30 seconds.

## Keep your key safe

* Call the API from your server or workflow tool, not from a browser or a mobile app.
* Store the key in an environment variable or a secrets manager, never in your code.
* If a key leaks, revoke it and create a new one.


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