# IdeaTokenExchange The `IdeaTokenExchange` handles the exchange (buy and sell) of `IdeaTokens` using a bonding curve for pricing. New`IdeaTokens` are minted on buy and existing `IdeaTokens` are burned on sell. The exchange also handles the distribution of generated interest aswell as trading and platform fees. * `buyTokens`: Buys `IdeaTokens` in exchange for `Dai`. The cost for the purchase is determined using the bonding curve * `address ideaToken`: The address of the IdeaToken to be bought * `uint amount`: The amount of IdeaTokens to buy * `uint fallbackAmount`: The amount of `IdeaTokens` to buy if the cost to buy `amount` exceeds `cost` (slippage). This can happen if the price changes between submitting the transaction and it being executed * `uint cost`: The maximum cost in `Dai` the buyer is willing to pay * `address recipient`: The recipient of the bought `IdeaTokens` * `sellTokens`: Sells `IdeaTokens` in exchange for `Dai`. The price is determined using the bonding curve * `address ideaToken`: The address of the `IdeaToken` to be sold * `uint amount`: The amount of `IdeaTokens` to sell * `uint minPrice`: The minimum price in `Dai` the seller wants for selling this `amount` of `IdeaTokens` (slippage) * `address recipient`: The recipient of the `Dai` When tokens are bought the spent Dai are invested into an interest generating protocol using the `InterestManager`. Currently this is `InterestManagerCompound` which invests `Dai` into Compound. Trading and platform fees are also collected according to the parameters set in the `IdeaTokenFactory`. When `allInterestToPlatform = false` then the interest which is generated by an `IdeaToken` can be withdrawn by the owner of the token using the `withdrawTokenInterest` method. The token owner must be previously set using `setTokenOwner` which is admin-only. If the owner is the zero address, i.e. an owner has not been set, a special account called the `authorizer` is allowed to initially set the token owner address. This allows for automated token owner verification without having to go through the timelock. Once the owner has been set the `authorizer` is not allowed to change the address anymore. Only the token owner and the admin (with timelock) can change it from now on. When `allInterestToPlatform = true` then all interest generated by the tokens in a market can be withdrawn by the platform owner using `withdrawPlatformInterest`. The platform owner must be previously set using `setPlatformOwner` which is admin-only. The same logic regarding the `authorizer` account applies as for `withdrawTokenInterest`. The collected platform fee can be withdrawn using `withdrawPlatformFee`. Again the platform owner must be set using `setPlatformOwner`. The collected trading fee can be withdrawn using `withdrawTradingFee`. This method is not protected and can be called by anyone as it will always send the trading fee to the `tradingFeeRecipient` which is passed to the contract during initialization. `setTokenFeeKillswitch` can be used to disable all trading and platform fee collection for a single `IdeaToken`. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.ideamarket.io/contracts/ideatokenexchange.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.