---
title: "ConnectionOpenInit defines a rpc handler method for MsgConnectionOpenInit."
method: POST
path: "/ibc.core.connection.v1.Msg/ConnectionOpenInit"
tags: ["Msg"]
---

# ConnectionOpenInit defines a rpc handler method for MsgConnectionOpenInit.

`POST /ibc.core.connection.v1.Msg/ConnectionOpenInit`

## Request body

- IbcCoreConnectionV1MsgConnectionOpenInit — MsgConnectionOpenInit defines the msg sent by an account on Chain A to initialize a connection with Chain B.
  - `client_id` string
  - `counterparty` IbcCoreConnectionV1Counterparty — Counterparty defines the counterparty chain associated with a connection end.
    - `client_id` string — identifies the client on the counterparty chain associated with a given connection.
    - `connection_id` string — identifies the connection end on the counterparty chain associated with a given connection.
    - `prefix` IbcCoreCommitmentV1MerklePrefix
      - `key_prefix` string, byte
  - `delay_period` string, uint64
  - `signer` string
  - `version` IbcCoreConnectionV1Version — Version defines the versioning scheme used to negotiate the IBC verison in the connection handshake.
    - `features` string[]
    - `identifier` string

## Response `200`

A successful response.

- IbcCoreConnectionV1MsgConnectionOpenInitResponse — MsgConnectionOpenInitResponse defines the Msg/ConnectionOpenInit response type.

## Other responses

- `default` — An unexpected error response.

## Changes

- **2024-08-14** `21c607e4fa20` — 1 info
  - api operation id `IbcCoreConnectionV1Msg_ConnectionOpenInit` removed and replaced with `FeeMsg_ConnectionOpenInit`
- **2024-02-23** `54713b4a9d25` — 1 info
  - endpoint added

[Change history](https://skmtc.dev/pokt-network/apis/http-api-console/changes/ibc.core.connection.v1.Msg/ConnectionOpenInit/post.md)

---

[API](https://skmtc.dev/pokt-network/apis/http-api-console.md) · [All operations](https://skmtc.dev/pokt-network/apis/http-api-console/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/pokt-network/http-api-console/revisions/29f6671190b2/schema)