From b238be750b09c8850e0a5bf83cca12f8c09cac8c Mon Sep 17 00:00:00 2001
From: wagmer <103462557+Anastasiia2803@users.noreply.github.com>
Date: Mon, 27 Oct 2025 16:40:24 +0200
Subject: [PATCH] Create CONTRIBUTING.md with contribution guidelines

Added a contributing guide with guidelines and constraints for contributions.
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 CONTRIBUTING.md | 23 +++++++++++++++++++++++
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 create mode 100644 CONTRIBUTING.md

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+# Contributing Guide
+
+Thanks for contributing to **megaeth-labs/chains** (fork of `ethereum-lists/chains`).  
+This repo stores EVM chain metadata under `_data/chains` using CAIP-2 file names.
+
+## ✅ Before you start
+- Each chain lives in `_data/chains/<caip-2>.json`. Example format with required fields is shown in README (name, chain, rpc[], nativeCurrency, explorers[], etc.).
+- If you reference an icon (network or explorer), provide a JSON in `_data/icons/<name>.json` with IPFS URLs, width/height, and format (png/jpg/svg). Files must be < 250 KB.  
+- `shortName` and `name` must be **unique**. If it’s an L2/shard, add a `parent` section linking to an existing parent chain.
+
+## 🔍 Constraints (summary)
+- Unique `shortName` and `name`.
+- If `parent` is used, the parent chain **must already exist**.
+- Icon JSON uses **publicly retrievable IPFS CIDs** (not gateway-only).
+- We do **not** delete historical chains; use `"status": "deprecated"` when needed.
+
+## 🧪 Pre-flight checks (please run locally before PR)
+```bash
+# validate / aggregate
+./gradlew run
+
+# format JSON consistently
+npx prettier --write _data/*/*.json