Reference

The IBC Rate Limit module provides a minimal middleware interface for forwarding IBC packet information to a CosmWasm contract.

Parameters

Queries

QueryParams

Retrieve the current module parameters.

REST:

GET /neutron/ibc-rate-limit/v1beta1/params

Response:

{
  "params": {
    "contract_address": "neutron1abcdef..."
  }
}

Messages

MsgUpdateParams

Update module parameters through governance.

Authority Required: Governance only

Fields:

• authority: Governance authority address
• params: New module parameters containing the contract address

Example:

{
  "@type": "/neutron.ibcratelimit.v1beta1.MsgUpdateParams",
  "authority": "neutron10d07y265gmmuvt4z0w9aw880jnsr700j7g7ejq",
  "params": {
    "contract_address": "neutron1newaddress..."
  }
}

Events

EventBadRevert

Emitted when the module fails to notify the contract about a failed packet.

Type: bad_revert

Attributes:

• module: rate-limited-ibc
• failure_type: Type of failure (acknowledgment or timeout)
• packet: The IBC packet data
• acknowledgement: The acknowledgement data (only present for acknowledgment failures)

Error Types

The module defines these error types:

Contract Interface

The module sends standardized sudo messages to the configured contract:

send_packet

Sent when an IBC packet is being transmitted from Neutron.

Message Structure:

{
  "send_packet": {
    "packet": {
      "sequence": 0,
      "source_port": "transfer",
      "source_channel": "channel-0",
      "destination_port": "omitted",
      "destination_channel": "omitted",
      "data": {
        "denom": "untrn",
        "amount": "1000000",
        "sender": "neutron1...",
        "receiver": "cosmos1..."
      },
      "timeout_height": {},
      "timeout_timestamp": 0
    }
  }
}

recv_packet

Sent when an IBC packet is being received by Neutron.

Message Structure:

{
  "recv_packet": {
    "packet": {
      // Same structure as send_packet
    }
  }
}

undo_send

Sent when a packet send fails and needs to be reverted.

Message Structure:

{
  "undo_send": {
    "packet": {
      // Same structure as send_packet
    }
  }
}

Module Behavior

• No Contract Set: If contract_address is empty, all transfers proceed without rate limiting
• Contract Set: All transfers are forwarded to the contract for approval
• Rate Limit Detection: Contract errors containing the substring "rate limit exceeded" return ErrRateLimitExceeded
• Other Contract Errors: All other contract errors return ErrContractError
• Failed Packet Handling: Automatically calls undo_send for timeouts and error acknowledgments