Params

danger

This document is relevant only for fungible token transfers over channels on v1 of the ICS-20 protocol.

Parameters

The IBC transfer application module contains the following parameters:

Name	Type	Default Value
SendEnabled	bool	true
ReceiveEnabled	bool	true

The IBC transfer module stores its parameters in its keeper with the prefix of 0x03.

SendEnabled

The SendEnabled parameter controls send cross-chain transfer capabilities for all fungible tokens.

To prevent a single token from being transferred from the chain, set the SendEnabled parameter to true and then, depending on the Cosmos SDK version, do one of the following:

• For Cosmos SDK v0.46.x or earlier, set the bank module's SendEnabled parameter for the denomination to false.
• For Cosmos SDK versions above v0.46.x, set the bank module's SendEnabled entry for the denomination to false using MsgSetSendEnabled as a governance proposal.

danger

Doing so will prevent the token from being transferred between any accounts in the blockchain.

ReceiveEnabled

The transfers enabled parameter controls receive cross-chain transfer capabilities for all fungible tokens.

To prevent a single token from being transferred to the chain, set the ReceiveEnabled parameter to true and then, depending on the Cosmos SDK version, do one of the following:

• For Cosmos SDK v0.46.x or earlier, set the bank module's SendEnabled parameter for the denomination to false.
• For Cosmos SDK versions above v0.46.x, set the bank module's SendEnabled entry for the denomination to false using MsgSetSendEnabled as a governance proposal.

danger

Doing so will prevent the token from being transferred between any accounts in the blockchain.

Queries

Current parameter values can be queried via a query message.

// proto/ibc/applications/transfer/v1/query.proto

// QueryParamsRequest is the request type for the Query/Params RPC method.
message QueryParamsRequest {}

// QueryParamsResponse is the response type for the Query/Params RPC method.
message QueryParamsResponse {
  // params defines the parameters of the module.
  Params params = 1;
}

To execute the query in simd, you use the following command:

simd query ibc-transfer params

Changing Parameters

To change the parameter values, you must make a governance proposal that executes the MsgUpdateParams message.

// proto/ibc/applications/transfer/v1/tx.proto

// MsgUpdateParams is the Msg/UpdateParams request type.
message MsgUpdateParams {
  // signer address (it may be the address that controls the module, which defaults to x/gov unless overwritten).
  string signer = 1;

  // params defines the transfer parameters to update.
  //
  // NOTE: All parameters must be supplied.
  Params params = 2 [(gogoproto.nullable) = false];
}

// MsgUpdateParamsResponse defines the response structure for executing a
// MsgUpdateParams message.
message MsgUpdateParamsResponse {}