Trade Types

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

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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 brigde. 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.

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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 necssary, or if calls do not need to be executed on destination.

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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 receieve 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 bridge requests that involve destination calls, like minting using an exact erc20 amount