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The Fee Refunder module manages fee distribution for IBC packet acknowledgements and timeouts, ensuring relayers are compensated for successful packet delivery.

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Parameters

ParameterTypeDescription
min_feeFeeMinimum required fees for IBC operations

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Fee Structure

  • recv_fee: Must be zero in Neutron (no receive fees)
  • ack_fee: Fees paid for acknowledgement delivery
  • timeout_fee: Fees paid for timeout delivery

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Messages

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MsgUpdateParams

Update module parameters through governance. Authority Required: Governance only Fields:
  • authority: Governance authority address
  • params: New module parameters

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Queries

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QueryParams

Retrieve the current module parameters. CLI: neutrond query feerefunder params REST: GET /neutron-org/neutron/feerefunder/params Response:
  • params: Current Fee Refunder parameters including min_fee

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QueryFeeInfo

Retrieve fee information for a specific IBC packet. CLI: neutrond query feerefunder fee-info [port_id] [channel_id] [sequence] REST: GET /neutron-org/neutron/feerefunder/info Parameters:
  • port_id: IBC port identifier
  • channel_id: IBC channel identifier
  • sequence: Packet sequence number
Response:
  • fee_info: Fee information containing payer, packet_id, and fee details

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Events

The module emits the following events:
  • lock_fees: When fees are locked for a new IBC packet
  • distribute_ack_fee: When acknowledgement fees are distributed to relayers
  • distribute_timeout_fee: When timeout fees are distributed to relayers

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Key Concepts

  • Automatic Distribution: Fees are automatically distributed when packets are acknowledged or timeout
  • Relayer Compensation: Ensures relayers are paid for successful packet delivery
  • Fee Escrow: Fees are locked when packets are sent and released upon completion
  • Query-Only for Users: Users can only query fee information and parameters
  • IBC Integration: Automatically handles fee distribution for IBC packets