---
name: hoi4-techtree-creator
description: Create or revise Tsareich2 Hearts of Iron IV technology trees, technology definitions, folder layout, countrytechtreeview GUI entries, technology GFX sprites, icons, categories, unlocks, and Japanese localisation.
---

# HOI4 Techtree Creator

Use this skill when adding or changing Tsareich2 technology folders, technologies, or technology tree GUI wiring.

## Required Context

- Read `AGENTS.md` before changing files.
- Follow `docs/gitflow.md`; work on a proper branch and do not edit on `main`.
- Preserve Tsareich2 style: 2 spaces, no tabs, one statement per line, nearby naming patterns.
- Prefer existing technology folders, GUI container patterns, GFX sprites, categories, and localisation keys.
- Add or update visible text in `localisation/japanese/`.
- Do not reuse external mod-specific IDs, tags, lore, or examples.

## Workflow

1. Inspect existing technology and GUI patterns:

```bash
rg -n 'technologies\s*=\s*\{|folder\s*=\s*\{|categories\s*=' common/technologies
rg -n 'containerWindowType|techtree_.*folder|countrytechtreeview' interface
rg -n -i 'GFX_.*tech|spriteType|technolog' interface gfx localisation/japanese
```

2. Choose a reference folder from Tsareich2 itself:

- Use the closest existing folder for canvas size, orientation, year spacing, category spacing, item sizes, and tab patterns.
- Do not use template numbers blindly; measure from `interface/countrytechtreeview.gui` and nearby `.gfx` files.

3. Define technologies:

- Place under the closest `common/technologies/` file or a focused new file.
- Use local variable names for rows, columns, years, and categories when the nearby file does.
- Set `folder`, `position`, `categories`, `research_cost`, `start_year`, prerequisites, and unlocks deliberately.
- Prefer existing equipment, modules, bonuses, or scripted effects over inventing disconnected unlocks.

4. Wire GUI and GFX:

- Add folder, tab, and item entries using the reference folder's structure.
- Define technology sprites in the closest existing `.gfx` file or a focused new one.
- Put new icons under an existing `gfx/interface/technologies/` pattern when assets are supplied.

5. Add localisation:

```yaml
l_japanese:
 tech_id:0 "..."
 tech_id_desc:0 "..."
 tech_folder_name:0 "..."
```

6. Verify:

```bash
rg -n 'tech_id|folder_name|GFX_.*tech_id' common/technologies interface localisation/japanese
rg -n '\t' common/technologies interface localisation/japanese
```

## References

- GUI template notes: `references/gui-templates.md`