Add forked env repo example

forked-env-example/.env.example

@@ -0,0 +1,5 @@
+# GMX Fork Testing Environment Variables
+
+# Arbitrum RPC URL (required)
+# You can use a public RPC or a provider like Alchemy/Infura for better performance
+ARBITRUM_RPC_URL=https://arb1.arbitrum.io/rpc

forked-env-example/.gitignore

@@ -0,0 +1,32 @@
+# Compiler files
+cache/
+out/
+
+# Dependencies
+lib/
+.gitmodules
+
+# Environment variables
+.env
+
+# Ignores development broadcast logs
+!/broadcast
+/broadcast/*/31337/
+/broadcast/**/dry-run/
+
+# Dotenv file
+.env
+.env.test
+
+# Node.js (if using Hardhat/TypeScript tooling)
+node_modules/
+
+# macOS
+.DS_Store
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~

forked-env-example/QUICKSTART.md

@@ -0,0 +1,60 @@
+# GMX Forked env example - Quick Start
+
+Standalone fork tests for GMX Synthetics V2 on Arbitrum. Describes the steps to open/close positions using real mainnet contracts.
+
+**Self-contained**: Copy this directory anywhere and follow the setup below.
+
+## Setup (2 minutes)
+
+```bash
+cd forked-env-example
+
+# Initialize git (required for forge install if setting up as a stand alone repo)
+git init
+
+# Install dependencies (just forge-std)
+forge install foundry-rs/forge-std --no-commit
+
+# Set Arbitrum RPC URL
+cp .env.example .env && source .env
+```
+
+## Run Tests
+
+```bash
+forge test --fork-url $ARBITRUM_RPC_URL -vv
+forge test --fork-url $ARBITRUM_RPC_URL --match-test testOpenLongPosition -vv
+forge test --fork-url $ARBITRUM_RPC_URL --match-test testCloseLongPosition -vv
+```
+
+## What This Does
+
+Tests demonstrate the GMX order flow:
+
+1. **Create order** - User sends collateral + execution fee to GMX
+2. **Execute order** - Keeper executes with oracle prices (mocked in these tests)
+3. **Verify position** - Check position was created/closed correctly
+
+Example: `testOpenLongPosition` opens a 2.5x leveraged long ETH position with 0.001 ETH collateral (~$3.89 → ~$9.7 position).
+
+## How It Works
+
+**Fork testing**: Tests run against real GMX contracts on Arbitrum mainnet at block 392496384 (matches a real transaction).
+
+**Oracle mocking**: GMX uses Chainlink Data Streams (off-chain signed prices). Oracle provider bytecode is replaced with a mock using **`vm.etch`** so orders can be executed without real signatures.
+
+**Key files**:
+- `contracts/constants/GmxArbitrumAddresses.sol` - Production contract addresses (all arbitrum deployments [here](https://github.com/gmx-io/gmx-synthetics/blob/main/docs/arbitrum-deployments.md))
+- `contracts/mocks/MockOracleProvider.sol` - Oracle price mocking. Critical step to bypass the Chainlink Data Stream signature verification on a forked env
+- `contracts/interfaces/IGmxV2.sol` - Minimal GMX interfaces. Miminal code copied from the GMX contracts/interfaces.
+- `contracts/utils/GmxForkHelpers.sol` - Reusable helpers for order creation, state queries
+- `test/GmxOrderFlow.t.sol` - Main test contract
+
+## What You'll Learn
+
+- How to create GMX orders (MarketIncrease, MarketDecrease)
+- Two-step execution model (user creates → keeper executes)
+- Handling oracle prices and execution fees
+- Querying positions and verifying state changes
+
+**Oracle provider address** mocked `0xE1d5a068c5b75E0c7Ea1A9Fe8EA056f9356C6fFD` (Chainlink Data Stream provider verified from mainnet txs).

forked-env-example/contracts/constants/GmxArbitrumAddresses.sol

@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+/**
+ * GMX Synthetics V2 contract addresses on Arbitrum mainnet
+ * @dev All addresses from official GMX deployments
+ * @dev Source: https://github.com/gmx-io/gmx-synthetics/blob/main/docs/arbitrum-deployments.md
+ * @dev Last Updated: Aug 13, 2025
+ */
+library GmxArbitrumAddresses {
+    // ============ Core Protocol Contracts ============
+
+    /// Central key-value store for all protocol data
+    address internal constant DATA_STORE = 0xFD70de6b91282D8017aA4E741e9Ae325CAb992d8;
+
+    /// Role-based access control
+    address internal constant ROLE_STORE = 0x3c3d99FD298f679DBC2CEcd132b4eC4d0F5e6e72;
+
+    /// Reader contract for querying protocol state
+    address internal constant READER = 0x65A6CC451BAfF7e7B4FDAb4157763aB4b6b44D0E;
+
+    /// Router contract for plugin transfers
+    address internal constant ROUTER = 0x7452c558d45f8afC8c83dAe62C3f8A5BE19c71f6;
+
+    /// Main entry point for creating deposits, withdrawals, and orders
+    address internal constant EXCHANGE_ROUTER = 0x87d66368cD08a7Ca42252f5ab44B2fb6d1Fb8d15;
+
+    /// Handles order execution logic
+    address internal constant ORDER_HANDLER = 0x04315E233C1c6FfA61080B76E29d5e8a1f7B4A35;
+
+    /// Oracle contract for price feeds
+    address internal constant ORACLE = 0x7F01614cA5198Ec979B1aAd1DAF0DE7e0a215BDF;
+
+    /// Oracle price store
+    address internal constant ORACLE_STORE = 0xA8AF9B86fC47deAde1bc66B12673706615E2B011;
+
+    /// Chainlink Data Streams oracle provider
+    /// @dev Used for WETH and USDC price feeds on mainnet
+    address internal constant CHAINLINK_DATA_STREAM_PROVIDER = 0xE1d5a068c5b75E0c7Ea1A9Fe8EA056f9356C6fFD;
+
+    /// Order vault - holds collateral for pending orders
+    address internal constant ORDER_VAULT = 0x31eF83a530Fde1B38EE9A18093A333D8Bbbc40D5;
+
+    /// Deposit handler
+    address internal constant DEPOSIT_HANDLER = 0x563E8cDB5Ba929039c2Bb693B78CE12dC0AAfaDa;
+
+    /// Withdrawal handler
+    address internal constant WITHDRAWAL_HANDLER = 0x1EC018d2b6ACCA20a0bEDb86450b7E27D1D8355B;
+
+    /// Event emitter
+    address internal constant EVENT_EMITTER = 0xC8ee91A54287DB53897056e12D9819156D3822Fb;
+
+    /// Deposit vault
+    address internal constant DEPOSIT_VAULT = 0xF89e77e8Dc11691C9e8757e84aaFbCD8A67d7A55;
+
+    /// Withdrawal vault
+    address internal constant WITHDRAWAL_VAULT = 0x0628D46b5D145f183AdB6Ef1f2c97eD1C4701C55;
+
+    // ============ Markets ============
+
+    /// ETH/USD perp market
+    /// @dev Long collateral: WETH, Short collateral: USDC, Index: WETH
+    address internal constant ETH_USD_MARKET = 0x70d95587d40A2caf56bd97485aB3Eec10Bee6336;
+
+    /// BTC/USD perp market
+    /// @dev Long collateral: WBTC, Short collateral: USDC, Index: WBTC
+    address internal constant BTC_USD_MARKET = 0x47c031236e19d024b42f8AE6780E44A573170703;
+
+    // ============ Tokens ============
+
+    /// Wrapped ETH on Arbitrum
+    address internal constant WETH = 0x82aF49447D8a07e3bd95BD0d56f35241523fBab1;
+
+    /// Native USDC on Arbitrum (not bridged)
+    address internal constant USDC = 0xaf88d065e77c8cC2239327C5EDb3A432268e5831;
+
+    /// Wrapped BTC on Arbitrum
+    address internal constant WBTC = 0x2f2a2543B76A4166549F7aaB2e75Bef0aefC5B0f;
+
+    /// USDC.e (bridged USDC from Ethereum)
+    address internal constant USDC_E = 0xFF970A61A04b1cA14834A43f5dE4533eBDDB5CC8;
+}