# MessageBusService

Roblox Engine API class from Roblox Studio 0.744.0.7441077 (version-7aaa6838d36c4448).

- Inherits from, nearest first: [Instance](https://rapi.sleaze.dev/classes/Instance.md), [Object](https://rapi.sleaze.dev/classes/Object.md)
- Tags: Not creatable, Not replicated, Service
- Memory category: Instances
- HTML page: https://rapi.sleaze.dev/classes/MessageBusService/
- Roblox documentation: https://create.roblox.com/docs/reference/engine/classes/MessageBusService

## Methods

### Call

```luau
MessageBusService:Call(key: string, input: any): any
```

- Tags: Roblox script security

### GetLast

```luau
MessageBusService:GetLast(mid: string): any
```

- Tags: Roblox script security

### GetMessageId

```luau
MessageBusService:GetMessageId(domainName: string, messageName: string): string
```

- Tags: Roblox script security

### GetProtocolMethodRequestMessageId

```luau
MessageBusService:GetProtocolMethodRequestMessageId(protocolName: string, methodName: string): string
```

- Tags: Roblox script security

### GetProtocolMethodResponseMessageId

```luau
MessageBusService:GetProtocolMethodResponseMessageId(protocolName: string, methodName: string): string
```

- Tags: Roblox script security

### MakeRequest

```luau
MessageBusService:MakeRequest(protocolName: string, methodName: string, message: any, callback: (...any) -> ...any, customTelemetryData: any)
```

- Tags: Roblox script security

### Publish

```luau
MessageBusService:Publish(mid: string, params: any)
```

- Tags: Roblox script security

### PublishProtocolMethodRequest

```luau
MessageBusService:PublishProtocolMethodRequest(protocolName: string, methodName: string, message: any, customTelemetryData: any)
```

- Tags: Roblox script security

### PublishProtocolMethodResponse

```luau
MessageBusService:PublishProtocolMethodResponse(protocolName: string, methodName: string, message: any, responseCode: number, customTelemetryData: any)
```

- Tags: Roblox script security

### SetRequestHandler

```luau
MessageBusService:SetRequestHandler(protocolName: string, methodName: string, callback: (...any) -> ...any)
```

- Tags: Roblox script security

### Subscribe

```luau
MessageBusService:Subscribe(mid: string, callback: (...any) -> ...any, once: boolean, sticky: boolean): Instance
```

- Tags: Roblox script security

### SubscribeToProtocolMethodRequest

```luau
MessageBusService:SubscribeToProtocolMethodRequest(protocolName: string, methodName: string, callback: (...any) -> ...any, once: boolean, sticky: boolean): Instance
```

- Tags: Roblox script security

### SubscribeToProtocolMethodResponse

```luau
MessageBusService:SubscribeToProtocolMethodResponse(protocolName: string, methodName: string, callback: (...any) -> ...any, once: boolean, sticky: boolean): Instance
```

- Tags: Roblox script security

## Inherited members

- From [Instance](https://rapi.sleaze.dev/classes/Instance.md): `Archivable`, `archivable`, `Attributes`, `AttributesReplicate`, `AttributesSerialize`, `HistoryId`, `Name`, `Parent`, `PredictionMode`, `PropertyStatusStudio`, `RobloxLocked`, `SerializedOverrides`, `SourceAssetId`, `Tags`, `UniqueId`, `numExpectedDirectChildren`, `DataCost`, `Capabilities`, `DefinesCapabilities`, `IsInSandbox`, `Sandboxed`, `AddTag`, `ClearAllChildren`, `Clone`, `Destroy`, `FindFirstAncestor`, `FindFirstAncestorOfClass`, `FindFirstAncestorWhichIsA`, `FindFirstChild`, `FindFirstChildOfClass`, `FindFirstChildWhichIsA`, `FindFirstDescendant`, `GetActor`, `GetAttribute`, `GetAttributeChangedSignal`, `GetAttributes`, `GetChildren`, `GetDebugId`, `GetDescendants`, `GetFullName`, `GetStyled`, `GetStyledPropertyChangedSignal`, `GetTags`, `HasTag`, `IsAncestorOf`, `IsDescendantOf`, `IsPropertyModified`, `QueryDescendants`, `RemoveTag`, `ResetPropertyToDefault`, `SetAttribute`, `WaitForChild`, `Remove`, `children`, `clone`, `destroy`, `findFirstChild`, `getChildren`, `isDescendantOf`, `remove`, `AncestryChanged`, `AttributeChanged`, `ChildAdded`, `ChildRemoved`, `DescendantAdded`, `DescendantRemoving`, `Destroying`, `StyledPropertiesChanged`, `childAdded`
- From [Object](https://rapi.sleaze.dev/classes/Object.md): `ClassName`, `className`, `GetPropertyChangedSignal`, `IsA`, `isA`, `Changed`