Fusion vs Lovable | agentconfig.ing

Fusion vs LovableComparisonUpdated 2026-03-16

SUMMARY

Fusion (IDE) uses mdc configuration while Lovable (Platform) uses markdown. They differ on 3 of 11 compared features. Both tools provide AI-assisted development but take different approaches to project configuration.

FEATURE COMPARISON

Feature	Fusion	Lovable	Notes
Config format	mdc	markdown
Hierarchy support	✗	✗	Whether config files can be placed at multiple directory levels
Global config	✗	✗	User-wide configuration outside any project
Project config	✓	✓
Subdirectory scoping	✗	✗	Config files in subdirectories that apply only to that subtree
File inclusion / imports	✗	✗	Ability to include or reference other files from config
Ignore file	✗	✗
IDE integration	✓	Platform
Schema / structure	Hybrid (MDC frontmatter + Markdown)	Free-form (Markdown)	Whether config uses structured schema or free-form content
Git committed	✓	✓	Whether primary config files are intended to be version-controlled
Encoding	UTF-8	UTF-8

FILE MAPPING

Purpose	Fusion	Lovable
Project instructions	AGENTS.md	AGENTS.md

SIDE-BY-SIDE CODE SAMPLES

Fusion

.builder/rules/*.mdc

mdc

---
description: React component conventions
globs: src/components/**/*.tsx
alwaysApply: false
---

# React Component Rules

## Structure
- Use functional components with TypeScript
- Define props interface above the component
- Export components as named exports

## Styling
- Use the project design system tokens for spacing and colors
- Prefer utility classes over custom CSS
- Keep component-specific styles colocated

## Patterns
- Wrap async data in Suspense boundaries
- Use forwardRef for reusable interactive components
- Keep components under 150 lines; extract hooks for logic

## Accessibility
- All interactive elements need aria-labels
- Use semantic HTML elements (nav, main, section)
- Ensure keyboard navigation works for custom widgets

Lovable

AGENTS.md

markdown

# Project Instructions

## Stack
- React 19 with TypeScript
- Supabase for backend (auth, database, storage)
- TailwindCSS v4 + shadcn/ui components
- Vite for building

## Architecture
- Feature-based folder structure
- Each feature owns its components, hooks, and types
- Shared components in src/components/ui/
- All API calls go through src/lib/supabase.ts

## Conventions
- Use shadcn/ui components before creating custom ones
- Mobile-first responsive design
- Use Supabase RLS policies for authorization
- Prefer server-side filtering over client-side

## Brand
- Primary color: #6366F1 (indigo)
- Font: Inter for body, Cal Sans for headings
- Rounded corners (radius-lg) on all cards

KEY DIFFERENCES

1. Config format

Fusion: mdc. Lovable: markdown.

2. IDE integration

Fusion: Supported. Lovable: Platform.

3. Schema / structure

Fusion: Hybrid (MDC frontmatter + Markdown). Lovable: Free-form (Markdown).

WHICH SHOULD I USE?

Recommendation

Choose based on your IDE/CLI preference. If you use Fusion, configure .builder/rules/*.mdc. If you use Lovable, configure AGENTS.md. Many projects include config files for multiple tools so each team member can use their preferred editor.

PORTABILITY TIP

sync-instructions.sh

bash

# Maintain a single source of truth:
cp AI-INSTRUCTIONS.md CLAUDE.md
cp AI-INSTRUCTIONS.md .cursorrules
cp AI-INSTRUCTIONS.md AGENTS.md