--- title: InstantiateMsg sidebar_label: InstantiateMsg sidebar_position: 1 slug: /contract-api/instantiate-msg --- # `InstantiateMsg` The `InstantiateMsg` is the message that is used to instantiate the `cw-ica-controller` contract. ```rust reference https://github.com/srdtrk/cw-ica-controller/blob/v0.4.0/src/types/msg.rs#L8-L21 ``` ## Fields ### `owner` This contract has an owner who is allowed to call the `ExecuteMsg` methods. The owner management is handled by the amazing [cw-ownable](https://crates.io/crates/cw-ownable) crate. If left empty, the owner is set to the sender of the `InstantiateMsg`. ### `channel_open_init_options` ```rust reference https://github.com/srdtrk/cw-ica-controller/blob/v0.4.0/src/types/msg.rs#L120-L132 ``` These are the options required for the contract to initiate an ICS-27 channel open handshake. This contract requires there to be an IBC connection between the two chains before it can open a channel. #### `connection_id` The identifier of the IBC connection end on the deployed (source) chain. (The underlying IBC light client must be live.) If this field is set to a non-existent connection, the execution of the `InstantiateMsg` will fail. #### `counterparty_connection_id` The identifier of the IBC connection end on the counterparty (destination) chain. (The underlying IBC light client must be live.) If this field is set to a non-existent connection or a different connection's end, then the execution of the `InstantiateMsg` will not fail. This is because the source chain does not know about the counterparty chain's connections. Instead, the channel open handshake will fail to complete. If the contract was instantiated with a `counterparty_connection_id` that does not match the connection end on the counterparty chain, then the owner must call [`ExecuteMsg::CreateChannel`](./02-execute-msg.mdx#createchannel) with the correct parameters to start a new channel open handshake. #### `counterparty_port_id` This is a required parameter for the ICS-27 channel version metadata. I've added it here for consistency. Currently, the only supported value is `icahost`. If left empty, it is set to `icahost`. **So you should ignore this field.** #### `tx_encoding` The ICS-27 implementation in `ibc-go` supports two transaction encoding formats: `proto3` and `proto3json`. This contract supports both formats, but defaults to `proto3`. This is because most chains don't yet support `proto3json` encoding. Moreover, this contract does not support some `CosmosMsg` while using `proto3json`. **So, if you are unsure, leave this field empty.** ### `send_callbacks_to` This is the address of the contract that will receive the callbacks from the `cw-ica-controller` contract. This may be the same address as the `owner` or a different address. If left empty, no callbacks will be sent. Learn more about callbacks [here](./04-callbacks.mdx).