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

# Trade Types

> Learn trade types Relay supports.

Relay supports three trade types: `exact_input`, `expected_output` and `exact_output`.

## Exact Input

The first supported type is `EXACT_INPUT`. In this order type, the user specifies how much of the input currency they want to provide for a swap or bridge.
The user is told how much of the output token they will receive for a given input.
This trade type fails if the input amount is too small to cover associated fees with the request. Associated fees can include but are not limited to
relay fees, app fees, and gas fees.

## Expected Output

The second supported type is `EXPECTED_OUTPUT`. In this order type, the user quotes via specifying the general amount of output currency they expected to receive from the swap or bridge. The user is then told how much of the origin token this will require. The resulting output amount received can be less or more than what is requested, depending on slippage.
This trade type automatically accounts for any associated fees including relay fees, app fees, and gas fees.
We recommend using `EXPECTED_OUTPUT` for when an exact output amount is not necessary, or if calls do not need to be executed on destination.

## Exact Output

The third supported type is `EXACT_OUTPUT`. In this order type, the user specifies exactly how much of the output currency they want to receive from the swap or bridge.
The user is told how much of the origin token this will require to receive exactly the output amount. If the exact requested amount out cannot be filled, the request is failed and the user is refunded on origin.
This trade type automatically accounts for any associated fees including relay fees, app fees, and gas fees.
We recommend using `EXACT_OUTPUT` for destination calls that require a precise output amount, like minting with an exact ERC20 amount. Destination calls also support `EXACT_INPUT` when you want to cap spend and accept a variable output.