Tunnel Creation

Anyone can broadcast MsgCreateTunnel to create a new data tunnel on BandChain. The formal specification of the message is given below:

// SignalDeviation is the type for a signal with soft and hard deviation
message SignalDeviation {
  option (gogoproto.equal) = true;

  // signal_id is the signal ID
  string signal_id = 1 [(gogoproto.customname) = "SignalID"];
  // deviation_bps is the deviation in basis points
  uint64 deviation_bps = 2 [(gogoproto.customname) = "HardDeviationBPS"];
}


// MsgCreateTunnel is the transaction message to create a new tunnel.
message MsgCreateTunnel {
  option (cosmos.msg.v1.signer) = "creator";
  option (amino.name)           = "tunnel/MsgCreateTunnel";

  // signal_deviations is the list of signal deviations.
  repeated SignalDeviation signal_deviations = 1 [(gogoproto.nullable) = false];
  // interval is the interval for delivering the signal prices in seconds.
  uint64 interval = 2;
  // route is the route for delivering the signal prices
  google.protobuf.Any route = 3 [(cosmos_proto.accepts_interface) = "RouteI"];
  // initial_deposit is the deposit value that must be paid at tunnel creation.
  repeated cosmos.base.v1beta1.Coin initial_deposit = 4 [
    (gogoproto.nullable)     = false,
    (gogoproto.castrepeated) = "github.com/cosmos/cosmos-sdk/types.Coins",
    (amino.dont_omitempty)   = true
  ];
  // creator is the address of the creator.
  string creator = 5 [(cosmos_proto.scalar) = "cosmos.AddressString"];
}

Signal Specification

When creating, the creator provides the list of SignalDeviation objects to specify the price symbols together with the time interval and price deviation to feed price data.

Field	Description
signal_id	The signal id (symbol) to feed price
deviation_bps	Additional price deviation threshold (in basis point)
interval	The default feeding interval in seconds

Tunnel Route

The creator also specifies the route to deliver price data to the destination, currently TSS, IBC, IBC Hook, and Router routes are supported.

Initial Deposit

The creator must seed the initial BAND token deposit to the tunnel. This initial deposit ensures that the tunnel is ready to operate immediately upon creation, provided it meets the minimum deposit requirements specified in the Tunnel Params. If the tunnel's balance falls below the required amount, others can send deposits to the tunnel by broadcasting a MsgDepositTunnel message to increase the total deposit of the tunnel by TunnelID.

Fee Payer Funds

Lastly, once a tunnel is created, a dedicated BandChain address will be generated as the fee payer. Anyone can send BAND tokens to this address to fund the tunnel for operations. As specified in the previous section, every message sent from a tunnel will incur various fees. If the tunnel runs out of BAND tokens, it will temporarily stop operating until more BAND tokens are sent and the creator broadcasts a MsgActivateTunnel message.