RouterMsg

The RouterMsg is an enum inside router-wasm-bindings. It contains one custom message type - CrosschainCall, which includes the destination chain ID & type, destination contract addresses, payload, the expiry timestamp for the request, the atomicity flag, among other things.

Sample Implementation of CrosschainCall

// import router binding message
use router_wasm_bindings::{RouterMsg, SudoMsg};
use router_wasm_bindings::types::{
    AckType, RequestMetaData,
};
use cosmwasm_std::{SubMsg, SubMsgResult, Uint128};

let request_packet: Bytes = encode(&[
    Token::String(destination_address.clone()),
    Token::Bytes(payload),
]);
let request_metadata: RequestMetaData = RequestMetaData {
    dest_gas_limit: gas_limit,
    dest_gas_price: gas_price,
    ack_gas_limit: 300_000,
    ack_gas_price: 10_000_000,
    relayer_fee: Uint128::zero(),
    ack_type: AckType::AckOnBoth,
    is_read_call: false,
    asm_address: String::default(),
};

let i_send_request: RouterMsg = RouterMsg::CrosschainCall {
    version: 1,
    route_amount,
    route_recipient,
    dest_chain_id: destination_chain_id,
    request_metadata: request_metadata.get_abi_encoded_bytes(),
    request_packet,
};

let cross_chain_sub_msg: SubMsg<RouterMsg> = SubMsg {
    id: CREATE_OUTBOUND_REPLY_ID,
    msg: i_send_request.into(),
    gas_limit: None,
    reply_on: ReplyOn::Success,
};
let res = Response::new()
    .add_submessage(cross_chain_sub_msg.into())
Ok(res)

The CrosschainCall is a data type that helps end users create a cross-chain request to any destination chain. It takes 6 arguments:

1) version - The network type of the chain to which the request needs to be sent.

2) route_amount - The ROUTE token amount that needs to be sent to the destination chain. To send ROUTE tokens to the specified destinaton chain, ROUTE will be burnt on the Router chain and minted on the destination chain.

3) route_recipient - The recipient address of the ROUTE token on the destination chain.

4) destination_chain_id - The network ID of the chain to which the request needs to be sent.

5) request_metadata - The request metadata is encoded data that includes dest_gas_limit, dest_gas_price, ack_gas_limit, ack_gas_price, relayer_fee, ack_type, is_read_call and asm_address. Further details for each one of these parameters can be found here.

6) request_packet - The request packet is encoded data that includes destination_address and payload. In the example given above, you can see how this encoding needs to be performed. Further detals for both of these parameters can be found here.