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

# WebSocket Common Standard Header

> This page defines the common standard headers and connection parameters for AllTick WebSocket market data interfaces, covering authentication-related fields, protocol version, compression, and more, so developers can establish secure and compatible connections for realtime quote streaming.

## Common Request Header Description

| Field | Name | Type | Required | Description |
| - | - | - | - | - |
| cmd\_id | Protocol number | uint32 | Provided in each interface definition | |
| seq\_id | Sequence number | uint32 | Yes | Generated uniquely by the requester. The response keeps the same value as the request. |
| trace | Trace ID | string | Yes | Generated uniquely by the requester. The response keeps the same value as the request. Maximum length: 64. |
| data | Data body | object | Yes | See each interface definition for the specific data format. |

```json theme={null}
{
  "cmd_id": 22000,
  "seq_id": 123,
  "trace": "asdfsdfa",
  "data": {}
}
```

## Common Response Header Description

| Field | Name | Type | Description |
| - | - | - | - |
| ret | Return value | int32 | [Error Code Description](https://alltick.co/apis/apis/en/getting-started/error-code-description.md) |
| msg | Message | string | Specific description of success or failure. |
| cmd\_id | Protocol number | uint32 | Provided in each interface definition. |
| seq\_id | Sequence number | uint32 | Generated uniquely by the requester. The response keeps the same value as the request. |
| trace | Trace ID | string | Generated uniquely by the requester. The response keeps the same value as the request. Maximum length: 64. |
| data | Data body | object | See each interface definition for the specific data format. |

```json theme={null}
{
  "ret": 201,
  "msg": "request header param invalid",
  "cmd_id": 0,
  "seq_id": 0,
  "trace": "",
  "data": {}
}
```

***

#### AllTick Website

> [!NOTE]
>
> Official website: \[[https://alltick.co/](https://alltick.co/)]\([https://alltick.co/](https://alltick.co/))


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