https://github.com/snarflakes/uniswap-python-swapper
Uniswap v4 Python Token Swapper – Universal Router. A user-friendly Python script that demonstrates how to execute SWAP_EXACT_IN (Exact Input) swaps on Uniswap v4 Universal Router across various L2 networks, leveraging the uniswap-universal-router-decoder library.
https://github.com/snarflakes/uniswap-python-swapper
arbitrum base cryptocurrency dex ethereum layer2 optimism polygon python uniswap uniswap-v4
Last synced: 2 months ago
JSON representation
Uniswap v4 Python Token Swapper – Universal Router. A user-friendly Python script that demonstrates how to execute SWAP_EXACT_IN (Exact Input) swaps on Uniswap v4 Universal Router across various L2 networks, leveraging the uniswap-universal-router-decoder library.
- Host: GitHub
- URL: https://github.com/snarflakes/uniswap-python-swapper
- Owner: snarflakes
- License: mit
- Created: 2025-02-05T19:34:47.000Z (4 months ago)
- Default Branch: main
- Last Pushed: 2025-02-05T20:04:57.000Z (4 months ago)
- Last Synced: 2025-02-05T20:47:53.182Z (4 months ago)
- Topics: arbitrum, base, cryptocurrency, dex, ethereum, layer2, optimism, polygon, python, uniswap, uniswap-v4
- Language: Python
- Homepage:
- Size: 24.4 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# Uniswap v4 Python Token Swapper – Universal Router
A **user-friendly Python script** that demonstrates how to execute **SWAP_EXACT_IN** (Exact Input) swaps on **Uniswap v4 Universal Router** across various L2 networks, leveraging the **uniswap-universal-router-decoder** library.
---
## Features
- **Supports** Uniswap v4 Universal Router.
- **Works** with both v3 and v4 (untested) pools.
- **Auto-selects** the router address based on the connected chain (Base, Optimism, Polygon, Arbitrum, Ethereum).
- **Permit2 integrated** for simplified token approvals.
- **Checks & Cancels** stuck transactions automatically.
- Written in **Python** using `web3.py`, `eth_account`, and `uniswap-universal-router-decoder`.
---
## Installation
1. **Clone This Repo** (or download the script directly)
2. **Install Dependencies**:
```bash
pip install web3 eth_account eth_abi uniswap-universal-router-decoder
```
3. **(Optional) Create a Virtual Environment**
```bash
python -m venv venv
source venv/bin/activate # On Linux/Mac
# or venv\Scripts\activate on Windows
```
4. **Ensure You Have Python 3.8+**
```bash
python --version
```
---
## Quick Start
```python
from web3 import Web3
from uniswap_universal_router import Uniswap # or whatever you name this script
# 1. Connect to an L2 or mainnet RPC
provider_url = "https://base-mainnet-rpc.example" # Replace with your provider
web3 = Web3(Web3.HTTPProvider(provider_url))
# 2. Prepare wallet credentials
wallet_address = "0xYOUR_WALLET_ADDRESS"
private_key = "YOUR_PRIVATE_KEY" # Keep secret!
# 3. Instantiate the Uniswap helper
uniswap = Uniswap(
wallet_address=wallet_address,
private_key=private_key,
provider=provider_url, # Used to auto-detect chain
web3=web3
)
# 4. Perform a swap (SWAP_EXACT_IN)
# Example: Swap 1 tokenIn -> tokenOut at 0.3% fee in a v3 pool
amount_in_wei = web3.to_wei(1, 'ether')
try:
tx_hash = uniswap.make_trade(
from_token="0xTOKEN_IN_ADDRESS",
to_token="0xTOKEN_OUT_ADDRESS",
amount=amount_in_wei,
fee=3000, # e.g., 3000 for a 0.3% Uniswap V3 pool
slippage=0.5, # non-functional right now. 0.5% slippage tolerance
pool_version="v3" # can be "v3" or "v4"
)
print(f"Swap transaction sent! Tx hash: {tx_hash.hex()}")
except Exception as e:
print(f"Swap failed: {e}")
```
---
## How It Works
1. **Router Detection:** Based on your `provider_url`, the script automatically selects the correct **Uniswap v4 Universal Router** address for Base, Optimism, Polygon, Arbitrum, or Ethereum.
2. **Permit2 Approvals:** Checks and (if necessary) approves the Uniswap Permit2 contract before swapping, minimizing repeated approvals.
3. **Transaction Construction:** Leverages `uniswap-universal-router-decoder` to encode swap calls. Handles `v3_swap_exact_in` or `v4_swap` logic depending on `pool_version`.
4. **Transaction Submission:** Signs and sends a **type=2** (EIP-1559) transaction with dynamic gas.
5. **Stuck Transactions Check:** If a nonce is stuck, attempts to cancel it by sending a 0-value tx with a higher gas.
6. **Stuck but not visible Transaction?:** Uncomment nonce, write in specific nonce that is the problem and it will attempt to cancel it by sending a 0-value tx with a higher gas.
---
## Code Overview
- **`Uniswap` class**
- **`__init__`:** Initializes Web3, detects chain, sets up router.
- **`approve_permit2`:** Approves the Permit2 contract with infinite allowance.
- **`check_permit2_allowance`:** Checks if there’s already sufficient allowance.
- **`create_permit_signature`:** Generates a Permit2 signature for the swap.
- **`make_trade`:** The main function for executing swaps.
- **`check_for_stuck_transactions`:** Detects if a transaction nonce is stuck in pending.
- **`cancel_transaction`:** Attempts to cancel a stuck transaction by overriding its nonce.
- **`calculate_gas_parameters`:** Estimates baseFee and priorityFee, calculates total cost.
---
## Supported Chains (with Addresses)
| Chain | Router Address |
|-----------|-----------------------------------------------|
| Ethereum | `0x66a9893cc07d91d95644aedd05d03f95e1dba8af` |
| Base | `0x6ff5693b99212da76ad316178a184ab56d299b43` |
| Optimism | `0x851116d9223fabed8e56c0e6b8ad0c31d98b3507` |
| Polygon | `0x1095692a6237d83c6a72f3f5efedb9a670c49223` |
| Arbitrum | `0xa51afafe0263b40edaef0df8781ea9aa03e381a3` |
> **Note:** These addresses may change if Uniswap deploys updates.
---
## Troubleshooting
- **Web3 Connection Failed:** Make sure your RPC URL is correct and the network is live.
- **Insufficient Balance or Allowance:** Ensure you have enough tokens/ETH for gas and correct Permit2 approvals.
- **Stuck Nonce:** The script automatically checks and attempts to cancel.
- **Unsupported Chain:** Add your chain to `ROUTER_ADDRESSES` or specify `ethereum`.
---
## Disclaimer
- **Use at your own risk** – This is experimental code for demonstration purposes.
- Always **test on a testnet** or with small amounts before using in production.
- Make sure you **keep your private keys secure**.
---
## Contributing
Pull requests are welcome! If you want to expand functionality or fix issues, feel free to open a PR.
---
## License
This project is released under the **MIT License**.
---
### Credits
- Built on top of [`uniswap-universal-router-decoder`](https://github.com/elnaril/uniswap-universal-router-decoder) for encoding/decoding logic.
- Thanks to [Web3.py](https://github.com/ethereum/web3.py/) and [Eth Account](https://github.com/ethereum/eth-account).