# Signature Authentication

When calling `TRADE` or `USER_DATA` endpoints, a signature must be included in the request header:

* **Header field:** `X-CH-SIGN`
* **Algorithm:** `HMAC SHA256`
* **Key:** Your API Secret (linked to your API Key)

### **Signature Construction**

The signature is generated using the following concatenated string:

```sql
sqlCopyEdittimestamp + method + requestPath + body
```

* `timestamp`: Same value as the `X-CH-TS` header
* `method`: HTTP method in **uppercase** (`GET`, `POST`, etc.)
* `requestPath`: API endpoint path (e.g., `/sapi/v1/order`)
* `body`: Raw string of the request body (for **POST** requests only; leave empty for GET)

The resulting string is hashed using HMAC SHA256 with your **API Secret** as the key.

> ⚠️ The signature value is **not case sensitive**.


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