# INCRBY

> Increment the integer value of a key by a given number.

If a key does not exist, it is initialized as 0 before performing the operation. An error is returned if the key contains a value of the wrong type or contains a string that can not be represented as integer.

## Arguments

<ParamField body="key" type="str"required>
The key to decrement.
</ParamField>
<ParamField body="increment" type="int" required>
The amount to increment by.
</ParamField>


## Response

<ResponseField  type="int" required>
The value at the key after the incrementing.
</ResponseField>

<RequestExample>
```py Example
redis.set("key", 6)

assert redis.incrby("key", 4) == 10
```
</RequestExample>