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

# IRouter

> Interface for the Router contract

# IRouter Interface

The `IRouter` interface defines the functions available in the Router contract, which serves as a central entry point for user interactions with the Satoshi Perps protocol.

## Plugin Management

```solidity theme={null}
function addPlugin(address _plugin) external;
```

Allows users to register a plugin that can execute actions on their behalf.

```solidity theme={null}
function removePlugin(address _plugin) external;
```

Removes a previously registered plugin.

```solidity theme={null}
function approvePlugin(address _plugin) external;
```

Approves a plugin to use the user's tokens via the Router.

```solidity theme={null}
function pluginTransfer(
    address _token,
    address _account,
    address _receiver,
    uint256 _amount
) external;
```

Transfers tokens from an account to a receiver, can only be called by an approved plugin.

```solidity theme={null}
function pluginIncreasePosition(
    address _account,
    address _collateralToken,
    address _indexToken,
    uint256 _sizeDelta,
    bool _isLong
) external;
```

Increases a position for an account, can only be called by an approved plugin.

```solidity theme={null}
function pluginDecreasePosition(
    address _account,
    address _collateralToken,
    address _indexToken,
    uint256 _collateralDelta,
    uint256 _sizeDelta,
    bool _isLong,
    address _receiver
) external returns (uint256);
```

Decreases a position for an account, can only be called by an approved plugin.

## Token Operations

```solidity theme={null}
function approvePlugin(address _token, address _spender) external;
```

Approves a specific token to be spent by the specified spender.

```solidity theme={null}
function swap(
    address[] memory _path,
    uint256 _amountIn,
    uint256 _minOut,
    address _receiver
) external;
```

Swaps tokens through the Vault's swap mechanism.

```solidity theme={null}
function swapETHToTokens(
    address[] memory _path,
    uint256 _minOut,
    address _receiver
) external payable;
```

Swaps ETH to tokens through the Vault's swap mechanism.

```solidity theme={null}
function swapTokensToETH(
    address[] memory _path,
    uint256 _amountIn,
    uint256 _minOut,
    address _receiver
) external;
```

Swaps tokens to ETH through the Vault's swap mechanism.

## ETH Handling

```solidity theme={null}
function unwrapETH(uint256 _amount, address _receiver) external;
```

Unwraps WETH to ETH and sends it to the specified receiver.

```solidity theme={null}
function directPoolDeposit(address _token, uint256 _amount) external;
```

Deposits tokens directly to the liquidity pool in the Vault.

```solidity theme={null}
function sendETHToVault(uint256 _amount) external;
```

Converts ETH to WETH and sends it to the Vault.

## Access Verification

```solidity theme={null}
function plugins(address _account, address _plugin) external view returns (bool);
```

Returns whether a plugin is registered for an account.

```solidity theme={null}
function approvedPlugins(address _account, address _plugin) external view returns (bool);
```

Returns whether a plugin is approved for an account.

## Usage Notes

* Before a plugin can execute actions on behalf of a user, the user must first register it using `addPlugin()` and then approve it using `approvePlugin()`.
* The Router delegates actual execution to the Vault but serves as a security layer and convenience wrapper.
* ETH handling functions provide convenience methods for working with ETH in a WETH-based system.

## Security Considerations

* Only approved plugins can execute actions on behalf of users
* Users should only approve trusted plugins as they will have significant control over the user's funds
* The Router does not hold user funds; it merely facilitates transfers and approvals