# RunService 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/RunService/ - Roblox documentation: https://create.roblox.com/docs/reference/engine/classes/RunService Service responsible for all runtime activity and progression of time. ## Properties ### ClientGitHash ```luau RunService.ClientGitHash: string ``` - Tags: Read only, Roblox script security, Read capabilities: Basic ### RunState ```luau RunService.RunState: Enum.RunState ``` - Tags: Not replicated, Write: Plugin security, Read capabilities: Basic + PluginOrOpenCloud The current run state of the game's simulation. ### FrameNumber ```luau RunService.FrameNumber: number ``` - Tags: Read only, Read capabilities: Basic + InternalTest, Write capabilities: InternalTest ## Methods ### BindToAnimation ```luau RunService:BindToAnimation(function: (...any) -> ...any, frequency: Enum.StepFrequency? = Enum.StepFrequency.Hz30, priority: number? = 2000): RBXScriptConnection ``` - Tags: Capabilities: Basic Binds a custom function to be called at a fixed frequency before Animators update when fixed simulation is enabled, or immediately before [`BindToSimulation`](https://rapi.sleaze.dev/classes/RunService.md) callbacks otherwise. Parameters: - `function`: The function to call. This function will be passed one parameter called `deltaTime`, which shows the elapsed time since the callback's previous invocation. - `frequency`: Optional `StepFrequency` value indicating the frequency at which to call the bound function. Defaults to `StepFrequency.Hz30`. - `priority`: Optional priority of the binding as an integer; it determines the order in which bound functions are called within a simulation step. Lower numbers are called first. If two bindings have the same priority, the order between them is unspecified. Defaults to 2000. Returns: A [`RBXScriptConnection`](https://rapi.sleaze.dev/index/types/RBXScriptConnection.md) that can be disconnected to unregister the callback. ### BindToRenderStep ```luau RunService:BindToRenderStep(name: string, priority: number, function: (...any) -> ...any) ``` - Tags: Capabilities: Basic Given a string name of a function and a priority, this method binds the function to [`RunService.PreRender`](https://rapi.sleaze.dev/classes/RunService.md). Parameters: - `name`: Label for the binding which can be used with `Unbind` if the binding is no longer needed. - `priority`: Priority of the binding as an integer; it determines when during the render step to call the custom function. The lower this number, the sooner the custom function will be called. If two bindings have the same priority, the engine will randomly pick one to run first. - `function`: The custom function being bound. ### BindToSimulation ```luau RunService:BindToSimulation(function: (...any) -> ...any, frequency: Enum.StepFrequency? = Enum.StepFrequency.Hz30, priority: number? = 2000): RBXScriptConnection ``` - Tags: Capabilities: Basic Binds a custom function to be called at a fixed frequency which is independent of the frame rate. Parameters: - `function`: The function to call. This function will be passed one parameter called `deltaTime` which shows how much time passed between the beginning of the previous simulation step and the beginning of the current simulation step. - `frequency`: Optional `StepFrequency` value indicating the frequency at which to call the bound function. If not provided, the default frequency will be used. - `priority`: Optional priority of the binding as an integer; it determines the order in which bound functions are called within a simulation step. Lower numbers are called first. If two bindings have the same priority, the order between them is unspecified. Defaults to 2000. Returns: An [`RBXScriptConnection`](https://rapi.sleaze.dev/index/types/RBXScriptConnection.md) that can be disconnected to unbind the function from the simulation step. ### GetControlAndVariantRolloutFlags ```luau RunService:GetControlAndVariantRolloutFlags(): ...any ``` - Tags: Roblox script security, Capabilities: Basic ### GetCoreScriptVersion ```luau RunService:GetCoreScriptVersion(): string ``` - Tags: Roblox script security, Capabilities: Basic ### GetPhysicsStepId ```luau RunService:GetPhysicsStepId(): number ``` - Tags: Roblox script security, Capabilities: Basic ### GetPredictionStatus ```luau RunService:GetPredictionStatus(context: Instance): Enum.PredictionStatus ``` - Tags: Capabilities: Basic, Simulation access Checks the `PredictionStatus` of a specific context instance, useful for debugging scripts affecting multiple instances where some might be predicted and others might not. Parameters: - `context`: The [`Instance`](https://rapi.sleaze.dev/classes/Instance.md) for which to check prediction status. Returns: The `PredictionStatus` of the given instance, indicating whether it is predicted, authoritative, or not participating in prediction. ### GetRobloxClientChannel ```luau RunService:GetRobloxClientChannel(): string ``` - Tags: Roblox script security, Capabilities: Basic ### GetRobloxClientIxpEnrolledExperiments ```luau RunService:GetRobloxClientIxpEnrolledExperiments(): string ``` - Tags: Roblox script security, Capabilities: Basic ### GetRobloxGuiFocused ```luau RunService:GetRobloxGuiFocused(): boolean ``` - Tags: Roblox script security, Capabilities: Basic ### GetRobloxVersion ```luau RunService:GetRobloxVersion(): string ``` - Tags: Roblox script security, Capabilities: Basic ### GetTotalScriptPlusExecutionTime ```luau RunService:GetTotalScriptPlusExecutionTime(): number ``` - Tags: Roblox script security, Capabilities: Basic ### IsClient ```luau RunService:IsClient(): boolean ``` - Tags: Thread safe, Capabilities: Basic Returns whether the current environment is running on the client. Returns: Whether the current environment is running the client. ### IsEdit ```luau RunService:IsEdit(): boolean ``` - Tags: Thread safe, Capabilities: Basic + PluginOrOpenCloud Returns whether the current environment is in `Edit` mode. Returns: Whether the current environment is in "edit" mode. ### IsResimulating ```luau RunService:IsResimulating(): boolean ``` - Tags: Thread safe, Capabilities: Basic, Simulation access Returns whether the client is currently in a resimulation step after a misprediction in the server authority model. Returns: Whether the engine is currently resimulating. ### IsRunMode ```luau RunService:IsRunMode(): boolean ``` - Tags: Thread safe, Capabilities: Basic Returns whether a **Run** playtest has been initiated in Studio. Returns: Whether a **Run** playtest has been initiated in Studio. ### IsRunning ```luau RunService:IsRunning(): boolean ``` - Tags: Capabilities: Basic Returns whether the experience is currently running. Returns: Whether the experience is currently running. ### IsServer ```luau RunService:IsServer(): boolean ``` - Tags: Thread safe, Capabilities: Basic Returns whether the current environment is running on the server. Returns: Whether the current environment is running on the server. ### IsStudio ```luau RunService:IsStudio(): boolean ``` - Tags: Thread safe, Capabilities: Basic Returns whether the current environment is running in Studio. Returns: Whether the current environment is running in Studio. ### IsTeamCreateViewer ```luau RunService:IsTeamCreateViewer(): boolean ``` - Tags: Roblox script security, Thread safe, Capabilities: Basic ### IsTeamTest ```luau RunService:IsTeamTest(): boolean ``` - Tags: Roblox script security, Thread safe, Capabilities: Basic ### Pause ```luau RunService:Pause() ``` - Tags: Plugin security, Capabilities: Basic Pauses the experience's simulation if it is running, suspending physics and scripts. ### Run ```luau RunService:Run() ``` - Tags: Plugin security, Capabilities: Basic Runs the game's simulation, running physics and scripts. ### Set3dRenderingEnabled ```luau RunService:Set3dRenderingEnabled(enable: boolean) ``` - Tags: Roblox script security, Capabilities: Basic ### SetPredictionMode ```luau RunService:SetPredictionMode(context: Instance, mode: Enum.PredictionMode) ``` - Tags: Capabilities: Basic Sets the prediction mode for an [`Instance`](https://rapi.sleaze.dev/classes/Instance.md) to an [`PredictionMode`](https://rapi.sleaze.dev/classes/Instance.md) value. Parameters: - `context`: The [`Instance`](https://rapi.sleaze.dev/classes/Instance.md) for which to set the prediction mode. - `mode`: The [`PredictionMode`](https://rapi.sleaze.dev/classes/Instance.md) to set for the context instance. ### SetRobloxGuiFocused ```luau RunService:SetRobloxGuiFocused(focus: boolean) ``` - Tags: Roblox script security, Capabilities: Basic ### Stop ```luau RunService:Stop() ``` - Tags: Plugin security, Capabilities: Basic Stops the experience's simulation if it is running. ### UnbindFromRenderStep ```luau RunService:UnbindFromRenderStep(name: string) ``` - Tags: Capabilities: Basic Unbinds a function that was bound to the render loop using [`RunService:BindToRenderStep()`](https://rapi.sleaze.dev/classes/RunService.md). Parameters: - `name`: The name of the function being unbound. ### getThrottleFramerateEnabled ```luau RunService:getThrottleFramerateEnabled(): boolean ``` - Tags: Roblox script security, Capabilities: Basic ### setThrottleFramerateEnabled ```luau RunService:setThrottleFramerateEnabled(enable: boolean) ``` - Tags: Roblox script security, Capabilities: Basic ### Reset ```luau RunService:Reset() ``` - Tags: Deprecated, Plugin security, Capabilities: Basic **Deprecated:** This item is deprecated and should not be used in new work. Resets the current game to a waypoint set when [`RunService:Run()`](https://rapi.sleaze.dev/classes/RunService.md) was called. ## Events ### Heartbeat ```luau RunService.Heartbeat: RBXScriptSignal<(deltaTime: number)> ``` - Tags: Capabilities: Basic Fires every frame, after the physics simulation has completed. ### Misprediction ```luau RunService.Misprediction: RBXScriptSignal<(time: number, instances: { any }, stats: { [string]: any })> ``` - Tags: Capabilities: Basic + PluginOrOpenCloud In the server authority model, fires during prediction when the engine detects that the client has diverged from the server's authoritative state. Intended for plugin-based debugging. ### PostSimulation ```luau RunService.PostSimulation: RBXScriptSignal<(deltaTimeSim: number)> ``` - Tags: Capabilities: Basic Fires every frame, after the physics simulation has completed. ### PreAnimation ```luau RunService.PreAnimation: RBXScriptSignal<(deltaTimeSim: number)> ``` - Tags: Capabilities: Basic Fires every frame, prior to the physics simulation but after rendering. ### PreRender ```luau RunService.PreRender: RBXScriptSignal<(deltaTimeRender: number)> ``` - Tags: Capabilities: Basic Fires every frame, prior to the frame being rendered. ### PreSimulation ```luau RunService.PreSimulation: RBXScriptSignal<(deltaTimeSim: number)> ``` - Tags: Capabilities: Basic Fires every frame, prior to the physics simulation. ### RenderStepped ```luau RunService.RenderStepped: RBXScriptSignal<(deltaTime: number)> ``` - Tags: Capabilities: Basic Fires every frame, prior to the frame being rendered. ### RobloxGuiFocusedChanged ```luau RunService.RobloxGuiFocusedChanged: RBXScriptSignal<(isRobloxGuiFocused: boolean)> ``` - Tags: Roblox script security, Capabilities: Basic ### Rollback ```luau RunService.Rollback: RBXScriptSignal<(time: number)> ``` - Tags: Capabilities: Basic In the server authority model, this fires after rolling back the predicted state due to a misprediction, but before resimulation begins. ### Stepped ```luau RunService.Stepped: RBXScriptSignal<(time: number, deltaTime: number)> ``` - Tags: Capabilities: Basic Fires every frame, prior to the physics simulation. ## 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`