feat(v1): add SafeERC20 support for USDT compatibility

.env.example

@@ -0,0 +1,42 @@
+# Deployer (DO NOT COMMIT REAL KEYS)
+DEPLOYER_PRIVATE_KEY=0x...
+
+# CREATE2 Salt (32 bytes, mined for desired vanity address)
+ETOMIC_SWAP_V1_CREATE2_SALT=0x...
+
+# ============ RPC URLs ============
+# Testnets
+SEPOLIA_RPC_URL=
+BSC_TESTNET_RPC_URL=
+POLYGON_MUMBAI_RPC_URL=
+AVALANCHE_TESTNET_RPC_URL=
+FANTOM_TESTNET_RPC_URL=
+
+# Mainnets
+MAINNET_RPC_URL=
+BSC_RPC_URL=
+POLYGON_RPC_URL=
+AVALANCHE_RPC_URL=
+ARBITRUM_RPC_URL=
+BASE_RPC_URL=
+KCC_RPC_URL=
+MOONRIVER_RPC_URL=
+MOONBEAM_RPC_URL=
+FANTOM_RPC_URL=
+HARMONY_RPC_URL=
+ETC_RPC_URL=
+RSK_RPC_URL=
+EWC_RPC_URL=
+SMARTBCH_RPC_URL=
+UBIQ_RPC_URL=
+QTUM_RPC_URL=
+
+# ============ BLOCK EXPLORER API KEYS ============
+ETHERSCAN_API_KEY=
+BSCSCAN_API_KEY=
+POLYGONSCAN_API_KEY=
+SNOWTRACE_API_KEY=
+ARBISCAN_API_KEY=
+BASESCAN_API_KEY=
+MOONSCAN_API_KEY=
+FTMSCAN_API_KEY=

.gitignore

@@ -61,4 +61,6 @@ typings/
 merge
 
 artifacts
-cache
+cache
+
+ignition/deployments/

DEPLOYMENTS.md

@@ -0,0 +1,94 @@
+# EtomicSwap V1 (SafeERC20) Deployments
+
+## Deployed Address (all chains)
+
+```
+0x61EEC68Cf64d1b31e41EA713356De2563fB6D3F1
+```
+
+Same address on every EVM chain via deterministic CREATE2 deployment.
+
+## Live Deployments
+
+| Chain | Chain ID | TX Hash | Explorer |
+|-------|----------|---------|----------|
+| Ethereum | 1 | `0xd78d0b7138fb1657da3d61e4db664d08b85fbcbb92ebf457cc8e3fa1f4d45a5c` | [etherscan.io](https://etherscan.io/address/0x61EEC68Cf64d1b31e41EA713356De2563fB6D3F1#code) |
+| Sepolia (testnet) | 11155111 | `0x0ce7879bdb6546e1a806bab1a8c09f990622bab69ae252cb79c5a04418a4150b` | [sepolia.etherscan.io](https://sepolia.etherscan.io/address/0x61EEC68Cf64d1b31e41EA713356De2563fB6D3F1#code) |
+
+## Deployment Steps
+
+The contract is deployed using [Hardhat Ignition](https://hardhat.org/ignition) with the CREATE2 strategy, which uses the [CreateX](https://github.com/pcaversaccio/createx) factory (`0xba5Ed099633D3B313e4D5F7bdc1305d3c28ba5Ed`) to produce deterministic addresses across chains.
+
+### Prerequisites
+
+1. Copy `.env.example` to `.env` and fill in:
+   - `DEPLOYER_PRIVATE_KEY` — the deployer wallet (`0x936c269a7378Ac408EF6EAB5770d29EA8EC6ecDd`)
+   - `ETOMIC_SWAP_V1_CREATE2_SALT` — the mined salt (see below)
+   - `ETHERSCAN_API_KEY` — for contract verification
+   - The RPC URL env var for the target chain (e.g., `BSC_RPC_URL`)
+
+2. Fund the deployer address with native gas on the target chain (~1.2M gas needed).
+
+3. Install dependencies:
+   ```bash
+   yarn install
+   ```
+
+### Deploy to a new chain
+
+```bash
+npx hardhat ignition deploy ignition/modules/EtomicSwapV1.js --network <network-name> --strategy create2
+```
+
+Where `<network-name>` matches a key in `hardhat.config.js` `networks` (e.g., `bsc`, `polygon`, `avalanche`).
+
+### Verify contract source
+
+```bash
+npx hardhat verify --network <network-name> 0x61EEC68Cf64d1b31e41EA713356De2563fB6D3F1
+```
+
+For chains using Etherscan V2, the single `ETHERSCAN_API_KEY` works. For chains with custom explorers (KCC, EWC), see `customChains` in `hardhat.config.js`.
+
+### Adding a new chain
+
+1. Add the network to `hardhat.config.js`:
+   ```js
+   newchain: networkConfig(<chainId>, "NEWCHAIN_RPC_URL"),
+   ```
+2. Add the RPC URL to `.env`
+3. Verify that [CreateX is deployed](https://github.com/pcaversaccio/createx#deployments) on the target chain
+4. Deploy and verify using the commands above
+5. Update this file with the TX hash and explorer link
+
+## Pending Deployments
+
+| Chain | Chain ID | Network Name | RPC Env Var |
+|-------|----------|--------------|-------------|
+| BSC | 56 | `bsc` | `BSC_RPC_URL` |
+| Polygon | 137 | `polygon` | `POLYGON_RPC_URL` |
+| Avalanche | 43114 | `avalanche` | `AVALANCHE_RPC_URL` |
+| Arbitrum One | 42161 | `arbitrumOne` | `ARBITRUM_RPC_URL` |
+| Base | 8453 | `base` | `BASE_RPC_URL` |
+| Fantom | 250 | `opera` | `FANTOM_RPC_URL` |
+| Moonriver | 1285 | `moonriver` | `MOONRIVER_RPC_URL` |
+| Moonbeam | 1284 | `moonbeam` | `MOONBEAM_RPC_URL` |
+| KCC | 321 | `kcc` | `KCC_RPC_URL` |
+| Harmony | 1666600000 | `harmony` | `HARMONY_RPC_URL` |
+| ETC | 61 | `etc` | `ETC_RPC_URL` |
+| RSK | 30 | `rsk` | `RSK_RPC_URL` |
+| EWC | 246 | `ewc` | `EWC_RPC_URL` |
+| SmartBCH | 10000 | `smartbch` | `SMARTBCH_RPC_URL` |
+| Ubiq | 8 | `ubiq` | `UBIQ_RPC_URL` |
+| Qtum | 3888 | `qtum` | `QTUM_RPC_URL` |
+
+## Background
+
+- **Contract**: `EtomicSwap.sol` with OpenZeppelin SafeERC20 (enables USDT and other non-standard ERC20 tokens)
+- **Deployer**: `0x936c269a7378Ac408EF6EAB5770d29EA8EC6ecDd`
+- **CreateX Factory**: [`0xba5Ed099633D3B313e4D5F7bdc1305d3c28ba5Ed`](https://github.com/pcaversaccio/createx)
+- **Salt**: `0x936c269a7378ac408ef6eab5770d29ea8ec6ecdd0050a3d70fd56cd902144e36`
+  - Bytes 0-19: deployer address (permissioned salt)
+  - Byte 20: `0x00` (cross-chain mode — same address on all chains)
+  - Bytes 21-31: mined entropy via [createXcrunch](https://github.com/pcaversaccio/createx-crunch)
+- **Previous V1 Contract** (no SafeERC20): `0x24ABE4c71FC658C91313b6552cd40cD808b3Ea80`