unity-input-system

name	unity-input-system
description	Unity Input System

Unity Input System

Use this skill when configuring input actions, reading player input, implementing rebinding, or migrating from Unity's legacy Input Manager to the New Input System.

Package Installation and Setup

Install via Package Manager or manifest:

// Packages/manifest.json
"com.unity.inputsystem": "1.8.2"

After installation, Unity prompts to switch the active input handling:

• Edit > Project Settings > Player > Active Input Handling -- set to Input System Package (New) or Both during migration
• Restart the editor after changing this setting

The new system is event-driven rather than poll-based. Instead of checking Input.GetKey() every frame, you define actions and respond to callbacks.

Action Types

Each action has a type that determines its behavior:

Type	When to Use	Example
Value	Continuous input, tracks state changes	Movement stick, mouse delta, triggers
Button	Discrete press/release, has default Press interaction	Fire, Jump, Interact
PassThrough	Raw input, no conflict resolution between devices	When you need every device's input simultaneously

Value actions perform conflict resolution -- if multiple controls are bound, only the most actuated one drives the action. PassThrough skips this and forwards all input.

// In the .inputactions editor:
// Move: Type = Value, Control Type = Vector2
// Fire: Type = Button
// AnyDeviceInput: Type = PassThrough

Input Action Phases

Every action fires callbacks at specific phases:

Phase	When	Use For
Started	Control actuated above default	Charge-up begins, button touch
Performed	Interaction completed	Fire bullet, jump, confirm
Canceled	Control released / interaction failed	Release charge, stop aiming

// Charge attack pattern
_input.Player.HeavyAttack.started += ctx => StartCharging();
_input.Player.HeavyAttack.performed += ctx => ReleaseCharge(); // Hold interaction completed
_input.Player.HeavyAttack.canceled += ctx => CancelCharge();   // Released too early

Input Debugger

Window > Analysis > Input Debugger shows:

• All connected devices and their controls in real-time
• Active actions and their current values
• Remote device connections (for debugging on-device builds)
• Event traces for diagnosing input issues

Enable Input Debug Mode in Project Settings > Input System for additional diagnostics.

Migration from Legacy Input

Legacy (UnityEngine.Input)	New Input System
Input.GetAxis("Horizontal")	moveAction.ReadValue<Vector2>().x
Input.GetButtonDown("Fire1")	fireAction.performed += ctx => ...
Input.GetKey(KeyCode.Space)	jumpAction.IsPressed()
Input.GetMouseButtonDown(0)	Bind <Mouse>/leftButton to action
Input.mousePosition	Mouse.current.position.ReadValue()
Input.GetJoystickNames()	Gamepad.all, InputSystem.devices
Input.GetAxisRaw("Vertical")	Set composite mode to Digital

Step-by-Step Migration

1. Set Active Input Handling to Both during migration
2. Create Input Actions asset mirroring your old axes/buttons
3. Replace Input.GetAxis() calls one script at a time
4. Test each script after conversion
5. Once all scripts converted, switch to Input System Package (New) only
6. Remove using UnityEngine.InputSystem; is the new namespace (not UnityEngine.Input)

Topic Pages

• Input Actions Asset
• Control Schemes
• Interactions
• Common Patterns