# Queries

{% hint style="info" %}
New queries can be added on request. If you cannot find the appropriate query for what you need, ask on our [Discord server](https://discord.gg/FK28WWHKyb).
{% endhint %}

### Authentication

All queries require an authentication header. You’ll need to provide a JWT token, which will be given to users that have access to Mercury ([get access](https://t.me/federicodeponti)). 

**Example Authentication Header**

Include the JWT in the request header as follows:

```bash
Authorization: Bearer YOUR_JWT_TOKEN
```

### Pagination & Limits

Paginated endpoints accept the following pagination params:

* `limit`  (default: 100, max: 1000) – requests exceeding the max are clamped to 1000  
* `offset` (default: 0) 
* `cursor` – the id (events) or tx hex (txs) of the last row from the previous page; when set, offset is ignored                                                                                           

### Example Variables for Docs

Will be used in the docs for the upcoming examples

```bash
# common vars
BASE="https://mainnet.mercurydata.app/rest"
AUTH="Bearer <your-jwt-here>"
```