> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cosmos.network/llms.txt
> Use this file to discover all available pages before exploring further.

# Parameters

> The Interchain Accounts module contains the following on-chain parameters, logically separated for each distinct submodule:

The Interchain Accounts module contains the following on-chain parameters, logically separated for each distinct submodule:

## Controller Submodule Parameters

| Name                | Type | Default Value |
| ------------------- | ---- | ------------- |
| `ControllerEnabled` | bool | `true`        |

### ControllerEnabled

The `ControllerEnabled` parameter controls a chains ability to service ICS-27 controller specific logic. This includes the sending of Interchain Accounts packet data as well as the following ICS-26 callback handlers:

* `OnChanOpenInit`
* `OnChanOpenAck`
* `OnChanCloseConfirm`
* `OnAcknowledgementPacket`
* `OnTimeoutPacket`

## Host Submodule Parameters

| Name            | Type      | Default Value |
| --------------- | --------- | ------------- |
| `HostEnabled`   | bool      | `true`        |
| `AllowMessages` | \[]string | `["*"]`       |

### HostEnabled

The `HostEnabled` parameter controls a chains ability to service ICS-27 host specific logic. This includes the following ICS-26 callback handlers:

* `OnChanOpenTry`
* `OnChanOpenConfirm`
* `OnChanCloseConfirm`
* `OnRecvPacket`

### AllowMessages

The `AllowMessages` parameter provides the ability for a chain to limit the types of messages or transactions that hosted interchain accounts are authorized to execute by defining an allowlist using the Protobuf message type URL format.

For example, a Cosmos SDK-based chain that elects to provide hosted Interchain Accounts with the ability of governance voting and staking delegations will define its parameters as follows:

```json theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}}
"params": {
  "host_enabled": true,
  "allow_messages": ["/cosmos.staking.v1beta1.MsgDelegate",
  "/cosmos.gov.v1beta1.MsgVote"]
}
```

There is also a special wildcard `"*"` value which allows any type of message to be executed by the interchain account. This must be the only value in the `allow_messages` array.

```json theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}}
"params": {
  "host_enabled": true,
  "allow_messages": ["*"]
}
```