> ## Documentation Index
> Fetch the complete documentation index at: https://docs-unity.molca.id/llms.txt
> Use this file to discover all available pages before exploring further.
# CSV Step Importer
> Import step metadata from CSV into a SequenceController hierarchy.
**Menu:** **Molca → Utilities → CSV Step Importer**\
**Script:** `Packages/com.molca.core/Editor/Sequence/CsvStepImporterWindow.cs`
Works with [Sequence Visualizer](/core/sequence-visualizer) (**Open CSV Step Importer** pre-fills the target controller) or standalone.
## Target controller
Assign a **`SequenceController`** in the **Controller** field. The importer creates or updates steps under that controller’s hierarchy according to CSV content and your column mapping.
## CSV file
Use **Browse…** to pick a `.csv` file. Row range controls and column-to-field mapping are configured in the window after load.
## Default column mappings
Mappings are built in **`InitializeColumnMappings`**:
* **Step Number** (required) — hierarchical step id (e.g. `1`, `1.1`, `2.1`).
* **Title** / **Title (`en`, `id`, …)** — one column per language code from **LocalizationModule** on [Global Settings](/setup/global-settings) when configured; otherwise a single **Title** column (required).
* **Description** — optional.
* **Extra columns** — via **`CsvStepImporterExtensibility.ExtraColumnMappings`** (see below).
Column index assignments can be persisted with **`EditorPrefs`** key `Molca.CsvStepImporter.ColumnMappings`.
## Extensibility
**`CsvStepImporterExtensibility`** (`CsvStepImporter.cs`):
* **`RegisterExtraColumnMapping`** — add columns and optional setup callbacks for custom **`StepInfo`** fields.
* **`StepInfoType`** — use a derived **`StepInfo`** type instead of the default.
* **`SetupCallbacks`** — run after base StepInfo setup.
* **`DrawExtraGUICallbacks`** — extra GUI after controller selection.
Use **`[InitializeOnLoad]`** or startup code in an Editor assembly to register extensions.
## Code (editor extension)
```csharp theme={null}
using Molca.Editor;
using UnityEditor;
[InitializeOnLoad]
internal static class MyCsvStepImporterHooks
{
static MyCsvStepImporterHooks()
{
CsvStepImporterExtensibility.RegisterExtraColumnMapping(
"Difficulty",
"Optional difficulty label from CSV",
required: false,
onSetup: (stepInfo, stepData) =>
{
if (stepData.extraColumnValues != null &&
stepData.extraColumnValues.TryGetValue("Difficulty", out var value))
{
// Cast stepInfo to your StepInfo-derived type and assign fields
}
});
}
}
```
See **`CsvStepImporterExtensibility`** in `CsvStepImporterWindow.cs` for **`StepInfoType`**, **`SetupCallbacks`**, and **`DrawExtraGUICallbacks`**.
## Related
* [Sequence Visualizer](/core/sequence-visualizer) — quick open with controller context
* VR-specific CSV extensions may live under `_MolcaSDK/_VR` (search for `CsvStepImporter` in the SDK)
## Unity Editor
