# UniqueIdLookupService

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, Service
- Memory category: Instances
- HTML page: https://rapi.sleaze.dev/classes/UniqueIdLookupService/
- Roblox documentation: https://create.roblox.com/docs/reference/engine/classes/UniqueIdLookupService

Team Create service that maps [`UniqueId`](https://rapi.sleaze.dev/index/types/UniqueId.md) to and from RFC-4122 strings; not for experience scripts.

## Methods

### GetInstanceByRfc4122String

```luau
UniqueIdLookupService:GetInstanceByRfc4122String(id: string): Instance
```

- Tags: Roblox script security

### GetOrCreateUniqueId

```luau
UniqueIdLookupService:GetOrCreateUniqueId(instance: Instance): string
```

- Tags: Roblox script security

### GetOrCreateUniqueIdRemoteCommand

```luau
UniqueIdLookupService:GetOrCreateUniqueIdRemoteCommand(instance: Instance): string
```

- Tags: Capabilities: RemoteCommand

Returns the RFC-4122 string form of the instance's [`UniqueId`](https://rapi.sleaze.dev/index/types/UniqueId.md), creating one if the instance does not already have it.

Parameters:

- `instance`: The instance whose [`UniqueId`](https://rapi.sleaze.dev/index/types/UniqueId.md) to read or create.

Returns: The instance's [`UniqueId`](https://rapi.sleaze.dev/index/types/UniqueId.md) as an RFC-4122 string.

## 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`