# IBC Connection

## Overview

For a detailed overview, please refer to the [official documentation.](https://ibc.cosmos.network/)

The below diagram depicts the interaction between two Cosmos SDK-based chains, Osmosis and Landslide, through the IBC protocol. The IBC Relayer acts as a mediator between the two chains.

When a message transfer is initiated by Chain A (Osmosis), it generates a packet commitment (hash) and stores it in the KV store by key (port, channel, sequence). Then it emits a packet event and the IBC Relayer handles this event. The IBC Relayer queries for the packet commitment proof from Chain A (Osmosis), which is then returned by Chain A (Osmosis). The IBC Relayer creates a message to relay the packet to Chain B (Landslide).

After receiving the message, Chain B (Landslide) sends back a WriteAck result to the IBC Relayer. The IBC Relayer then queries for the acknowledgement proof from Chain B (Landslide), which is then returned by Chain B (Landslide). The IBC Relayer creates an acknowledgement message containing the packet, acknowledgement, and proofs, which is then sent to Chain A (Osmosis).

{% @mermaid/diagram content="sequenceDiagram

```
participant Chain A (Osmosis)
participant IBC Relayer
participant Chain B (Landslide)
Chain A (Osmosis)->>Chain A (Osmosis): Process MsgTransfer Message
Note left of Chain A (Osmosis): *Create IBC Packet <br>*Generate Packet<br>commitment (hash)<br>* Store Packet commitment<br>in KV Store by key<br>(port, channel, sequence)<br>* Emit Packet Event
```

Chain A (Osmosis)->>IBC Relayer: Handle Packet Event
IBC Relayer->>Chain A (Osmosis): Query Packet Commitment Proof
Chain A (Osmosis)-->>IBC Relayer: Returns Proof
Note over IBC Relayer: Create MsgRecvPacket<br/>with packet and proofs
IBC Relayer->>Chain B (Landslide): Relay Message
Chain B (Landslide)-->>IBC Relayer: Get WriteAck result
IBC Relayer->>Chain B (Landslide): Query Acknowledgement Proof
Chain B (Landslide)-->>IBC Relayer: Returns Proof
Note over IBC Relayer: Create MsgAcknowledgement<br/>with packet, ack, and proofs
IBC Relayer->>Chain A (Osmosis): Send Ack message
" %}

A more detailed view

{% @mermaid/diagram content="sequenceDiagram

participant Chain A
participant Relayer
participant Chain B

opt Setup Clients
Relayer->>Chain A: Create Client
Chain A-->>Relayer: Returns ClientID
Relayer->>Chain B: Create Client
Chain B-->>Relayer: Returns ClientID
end

opt Create Connections
Relayer->>Chain A: Calls ConnectionOpenInit
Chain A-->>Relayer: Returns ConnectionID
opt Query Proofs
Relayer->>Chain A: Query proof for the client state at latest height
Chain A-->>Relayer: Returns ProofClient and ProofHeight by ClientID
Relayer->>Chain A: Query proof for the consensus state at ProofHeight
Chain A-->>Relayer: Returns ProofConsensus
Relayer->>Chain A: Query proof for the connection at ProofHeight
Chain A-->>Relayer: Returns ProofConnection
end
note right of Relayer: with ProofClient, ProofConsensus, ProofConnection
Relayer->>Chain B: Calls ConnectionOpenTry
Chain B-->>Relayer: Returns ConnectionID
opt Query Proofs
Relayer->>Chain B: Query proof for the client state at latest height
Chain B-->>Relayer: Returns ProofClient and ProofHeight by ClientID
Relayer->>Chain B: Query proof for the consensus state at ProofHeight
Chain B-->>Relayer: Returns ProofConsensus
Relayer->>Chain B: Query proof for the connection at ProofHeight
Chain B-->>Relayer: Returns ProofConnection
end
note left of Relayer: with ProofClient, ProofConsensus, ProofConnection
Relayer->>Chain A: Calls ConnectionOpenAck
opt Query Proofs
Relayer->>Chain B: Query proof for the connection at latest height
Chain B-->>Relayer: Returns ProofConnection and ProofHeight
end
Relayer->>Chain B: Calls ConnectionOpenConfirm
Relayer->>Chain A: Update Client
end

opt Setup Channels
Relayer->>Chain A: Calls ChannelOpenInit
Chain A-->>Relayer: Returns ChannelID
opt Query Proofs
Relayer->>Chain A: Query channel proof
Chain A-->>Relayer: Returns proof and height
end
note right of Relayer: with ChannelProof
Relayer->>Chain B: Calls ChannelOpenTry
Chain B-->>Relayer: Returns ChannelID
opt Query Proofs
Relayer->>Chain B: Query channel proof
Chain B-->>Relayer: Returns proof and height
end
note left of Relayer: with ChannelProof
Relayer->>Chain A: Calls ChannelOpenAck
opt Query Proofs
Relayer->>Chain A: Query channel proof
Chain A-->>Relayer: Returns proof and height
end
note right of Relayer: with ChannelProof
Relayer->>Chain B: Calls ChannelOpenConfirm
end
" %}