fusengine Requires detecting the project's primitive first (shadcn-detection) and consulting the shadcn MCP for registry source instead of hand-writing component internals.
shadcn Components
Agent Workflow (MANDATORY)
Before component work, spawn agents in parallel, one Agent call each with a name:
- fuse-ai-pilot:explore-codebase - Find existing components
- fuse-ai-pilot:research-expert - Verify component APIs via Context7
- mcp__shadcn__search_items_in_registries - Search available components
After: Run fuse-ai-pilot:sniper for validation.
Overview
| Feature | Description |
|---|---|
| Radix primitives | Default shadcn/ui since 2021 |
| Base UI primitives | New option since late 2025 |
| Component mapping | 1:1 mapping between both |
| API differences | asChild vs render, naming |
Critical Rules
- ALWAYS detect primitive before component work (shadcn-detection)
- ALWAYS consult MCP before adding any component
- NEVER mix Radix and Base UI APIs in same component
- MATCH composition pattern to detected primitive
- USE registry source as truth, not manual code
Architecture
components/ui/
├── dialog.tsx # Adapted to detected primitive
├── select.tsx
├── accordion.tsx
└── ...
-> See dialog-example.md for complete component
MCP Usage (MANDATORY)
ALWAYS consult shadcn MCP before adding components:
mcp__shadcn__search_items_in_registries -> find component
mcp__shadcn__view_items_in_registries -> view source
mcp__shadcn__get_add_command_for_items -> get install command
Component Mapping Table
| Component | Radix Part | Base UI Part |
|---|---|---|
| Dialog | DialogContent |
Dialog.Popup |
| Dialog | DialogOverlay |
Dialog.Backdrop |
| Select | SelectContent |
Select.Positioner + Select.Popup |
| Tooltip | TooltipContent |
Tooltip.Positioner + Tooltip.Popup |
| Accordion | AccordionContent |
Accordion.Panel |
| Popover | PopoverContent |
Popover.Positioner + Popover.Popup |
| Menu | DropdownMenuContent |
Menu.Positioner + Menu.Popup |
Composition Patterns
Radix: asChild
<Dialog.Trigger asChild>
<Button variant="outline">Open</Button>
</Dialog.Trigger>
Base UI: render
<Dialog.Trigger render={<Button variant="outline" />}>
Open
</Dialog.Trigger>
Reference Guide
Concepts
| Topic | Reference | When to Consult |
|---|---|---|
| Radix APIs | radix-components.md | Building with Radix primitives |
| Base UI APIs | baseui-components.md | Building with Base UI primitives |
Templates
| Template | When to Use |
|---|---|
| dialog-example.md | Creating Dialog components |
Best Practices
DO
- Detect primitive FIRST (use shadcn-detection)
- Consult MCP for component source before editing
- Follow existing naming conventions in project
- Use correct composition pattern for detected primitive
DON'T
- Mix asChild and render in same component
- Assume Radix without detection
- Manually write component internals (use MCP)
- Skip registry check before adding new components