From 1d03d10ba8bbd7e908e4a5259683086969ffee90 Mon Sep 17 00:00:00 2001
From: Dayuan Jiang <34411969+DayuanJiang@users.noreply.github.com>
Date: Sat, 6 Dec 2025 17:39:47 +0900
Subject: [PATCH] docs: add CONTRIBUTING.md (#119)

---
 CONTRIBUTING.md | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 CONTRIBUTING.md

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..ec6b88a
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,35 @@
+# Contributing
+
+## Setup
+
+```bash
+git clone https://github.com/YOUR_USERNAME/next-ai-draw-io.git
+cd next-ai-draw-io
+npm install
+cp env.example .env.local
+npm run dev
+```
+
+## Code Style
+
+We use [Biome](https://biomejs.dev/) for linting and formatting:
+
+```bash
+npm run format   # Format code
+npm run lint     # Check lint errors
+npm run check    # Run all checks (CI)
+```
+
+Pre-commit hooks via Husky will run Biome automatically on staged files.
+
+For a better experience, install the [Biome VS Code extension](https://marketplace.visualstudio.com/items?itemName=biomejs.biome) for real-time linting and format-on-save.
+
+## Pull Requests
+
+1. Create a feature branch
+2. Make changes and ensure `npm run check` passes
+3. Submit PR against `main` with a clear description
+
+## Issues
+
+Include steps to reproduce, expected vs actual behavior, and AI provider used.