> For the complete documentation index, see [llms.txt](https://docs.bancor.network/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.bancor.network/developer-guides/write-functions/rewards/join.md).

# join()

### Function join()

{% code title="StandardRewards.sol" %}

```solidity
function join(uint256 id, uint256 poolTokenAmount) external greaterThanZero(poolTokenAmount) nonReentrant \
```

{% endcode %}

This function is used to deposit Bancor pool tokens (bnTokens) into a rewards program. 

{% hint style="info" %}
This function requires approval to be set for the relevant pool tokens prior to calling the function. 
{% endhint %}

The function accepts a reward program ID and the number of pool tokens as arguments, and does not return anything. 

### Function Arguments

| Name            | Type    | Description                            |
| --------------- | ------- | -------------------------------------- |
| id              | uint256 | This is the ID of the rewards program. |
| poolTokenAmount | uint256 | The number of pool tokens.             |