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+# Contributing Guide — MegaETH Chains
+
+Welcome and thank you for contributing!  
+This repository contains EVM-compatible chain metadata following the [ethereum-lists/chains](https://github.com/ethereum-lists/chains) schema.
+
+## ✅ Before You Start
+- Each chain lives in `_data/chains/<caip-2>.json`.  
+- Icons go into `_data/icons/<name>.json` with valid IPFS URLs (max 250 KB).  
+- `shortName` and `name` must be unique across the repo.  
+- For L2/shard networks, define the `parent` section properly.
+
+## 🧪 Local Validation
+Run locally before submitting:
+```bash
+./gradlew run
+npx prettier --write _data/*/*.json