> ## Documentation Index
> Fetch the complete documentation index at: https://developer.z-api.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Lid

## Introduction

The `@lid` (Linked ID) is a *unique and private identifier* created by WhatsApp to represent contacts without directly exposing their phone number.
This change is part of WhatsApp's *privacy updates*, allowing users to hide their number in certain contexts.

In some cases, WhatsApp is sending the `@lid` as the primary user identifier, even if the user hasn't enabled any option to hide their number.

***

### Difference between `@lid` and `phone`

WhatsApp can return contact identifiers in different ways, depending on the type of conversation, group, or privacy settings:

* `phone`: Can contain the real number (`"554499999999"`) or the `@lid` itself (`"999999999999999@lid"`).

* `chatLid`: Is the most stable unique identifier.

***

### Webhook Example

In Z-API webhooks, WhatsApp can return the contact identifier in different ways, depending on the type of interaction and the user's privacy settings.

#### Example – Full return with number and `@lid`:

```json theme={"theme":{"light":"github-light","dark":"poimandres"}}
{
  "chatLid": "999999999999999@lid",
  "phone": "554499999999"
}
```

#### Example – Return with `@lid` only:

```json theme={"theme":{"light":"github-light","dark":"poimandres"}}
{
  "chatLid": "65998849469@lid",
  "phone": "65998849469@lid"
}
```

***

### Sending messages using `@lid`

You can *send messages directly to an `@lid`*, replacing the phone number in the request body:

```json theme={"theme":{"light":"github-light","dark":"poimandres"}}
{
  "phone": "999999999999999@lid",
  "message": "Hello! This message was sent using the @lid identifier."
}
```

Sending works normally, as the `@lid` is *already supported* by the Z-API in most endpoints.

***

### Implementation best practices

* Prioritize using `@lid` to identify contacts — this attribute tends to be the most stable.
* Avoid relying solely on `phone`, as it may contain the number or the `@lid` itself.
* Store and relate the `@lid` in your database to maintain consistency.

***

### Converting `@lid` to phone number

It is not possible to convert an `@lid` to a phone number.
This limitation exists *for privacy reasons defined by WhatsApp*.
Allowing this conversion would invalidate the purpose of the number-hiding feature.

***

### Converting phone number to `@lid`

On the other hand, it is possible to obtain the `@lid` corresponding to a phone number using the ["Is on WhatsApp?"](https://developer.z-api.io/contacts/get-iswhatsapp) method.

***

### Important

* This change is *native to WhatsApp*, and Z-API only passes along the information as received.
* The return behavior (`@lid` or `phone`) may vary.
* The `chatLid` attribute is already implemented in Z-API webhooks and can be used both to identify contacts and to send messages.
* The `@lid` is being gradually implemented by WhatsApp itself, so behavior may be inconsistent.