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Unity Integration for the dialogue scripting tool topiary with the C# bindings.

Checkout the syntax file if you're new to writing with Topi.


Can be installed via the Package Manager > Add Package From Git URL...

This repo has a dependency on the EvtVariable package which MUST be installed first. (From my understanding Unity does not allow git urls to be used as dependencies of packages)

This package also depends on the Unity Addressables package, which should automatically be installed, but if you any issues please install it manually from the Package Manager.

then the repo can be added


You'll need some sort of singleton DialogueRunner to go between Topiary and your UI.

Here's a rough sketch:

public class DialogueRunner : MonoBehaviour
private void Awake()
Conversation.OnStart += OnStart;
Conversation.OnEnd += OnEnd;
Conversation.OnLine += OnLine;
Conversation.OnChoices += OnChoices;

private void OnDestroy()
Conversation.OnStart -= OnStart;
Conversation.OnEnd -= OnEnd;
Conversation.OnLine -= OnLine;
Conversation.OnChoices -= OnChoices;

private void OnStart(Dialogue dialogue, Conversation conversation)
// Update the UI
// Perform any tasks for line mode

private void OnLine(Dialogue dialogue, Line line, TopiSpeaker topiSpeaker)
// Update the UI to display the line
// Use dialogue.SelectContinue() to continue the dialogue

private void OnChoices(Dialogue dialogue, Choice[] choices)
// Update the UI to display the choices
// Use dialogue.SelectChoice(int) when the player makes their selection

private void OnEnd(Dialogue dialogue, Conversation conversation)
// Close your UI
// Perform any clean up tasks
// Revert back to game mode


Any .topi file will automatically be compiled and a subasset will be created with the .topib bytecode.

Once your file is compiled it will automatically be added to a Topiary addressables group with the labels Topiary and Topi.

Add a Conversation MonoBehaviour to a GameObject and select the .topi file you want to associate with that Conversation.

Trigger the start of the Conversation in anyway you like with conversation.PlayDialogue() or StartCoroutine(conversation.Play())


Topiary can call external functions that are marked with the Topi attribute. Here's some examples:

// Preserve used to make sure Unity doesn't strip these functions from your build
public static class DialogueFunctions
// playAnim will be replaced with the C# method
// we give the playAnim function a body in our .topi file for testing
// a warning will be shown if any extern isn't set when we start our Dialogue
// ex .topi file:
// extern const playAnim = |name, clip| {}
// playAnim("Player", "Laugh")
[Topi("playAnim", 2)]
public static TopiValue PlayAnim(IntPtr argsPtr, byte count)
var args = TopiValue.CreateArgs(argsPtr, count);
var speakerName = args[0];
var animClip = args[1];
if (!Conversation.Speakers.TryGetValue(speakerName.String, out var topi) ||
!topi.TryGetComponent(out Speaker speaker)) return default;
return default;


I wanted to hide away the TopiValue implementation details, but without boxing everything to just object it didn't seem viable.

So instead here's your warning: TopiValues have data are explicitly mapped out in memory and different fields are overlaying each other.

public struct TopiValue : IDisposable, IEquatable<TopiValue>
[MarshalAs(UnmanagedType.U1)] public Tag tag;
private TopiValueData _data;

public struct TopiValueData
[FieldOffset(0)] [MarshalAs(UnmanagedType.I1)]
public byte boolValue;

[FieldOffset(0)] [MarshalAs(UnmanagedType.R4)]
public float numberValue;

[FieldOffset(0)] public IntPtr stringValue;

[FieldOffset(0)] public TopiList listValue;

This means you are required to check the tag field before accessing the data to know which field is currently active or use a switch statement. If you prefer to accept an object you can use the Value property. Or if you're sure of the type (like in the Topi functions above) you can use the named properties directly, just be careful. Bool, Int, Float, String, List, Set, Map.

var value = new TopiValue(true);
value.Float // Incorrect property access, throws an error or returns malformed/incorrect data
value.String // Incorrect property access, throws an error or returns malformed/incorrect data
value.Bool // true


I've made EvtVariables the scriptableobject event system architecture a dependency of this package, though isn't actually necessary a lot of my tools use it. If you prefer not to keep it, please feel free to fork this repo and remove it.

EvtVariables are extents as EvtTopiVariables and used as runtime variable containers for any .topi extern variable.

Create one with ContextMenu > Create > Evt > Topiary > [Type]

Then set the Topi Variable Name to the name in the .topi file.

Topiary.Unity will automatically add the object to the Addressables Topiary group with labels Topiary and Evt. Then each Conversation will automatically load the EvtVariables and hook up callbacks with the Topiary VM.