diff --git a/contracts/StableAssetFactory.sol b/contracts/StableAssetFactory.sol
new file mode 100644
index 0000000..bc86fa8
--- /dev/null
+++ b/contracts/StableAssetFactory.sol
@@ -0,0 +1,160 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.18;
+
+import "@openzeppelin/contracts-upgradeable/token/ERC20/ERC20Upgradeable.sol";
+import "@openzeppelin/contracts-upgradeable/token/ERC20/extensions/ERC20BurnableUpgradeable.sol";
+import "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";
+import "@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol";
+import "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";
+import "@openzeppelin/contracts-upgradeable/utils/math/SafeMathUpgradeable.sol";
+import "@openzeppelin/contracts/proxy/transparent/TransparentUpgradeableProxy.sol";
+import "@openzeppelin/contracts/proxy/transparent/ProxyAdmin.sol";
+
+import "./StableAsset.sol";
+import "./TapETH.sol";
+import "./misc/ConstantExchangeRateProvider.sol";
+
+/**
+ * @title StableAsset Application
+ * @author Nuts Finance Developer
+ * @notice The StableSwap Application provides an interface for users to interact with StableSwap pool contracts
+ * @dev The StableSwap Application contract allows users to mint pool tokens, swap between different tokens, and redeem pool tokens to underlying tokens.
+ * This contract should never store assets.
+ */
+contract StableAssetFactory is Initializable, ReentrancyGuardUpgradeable {
+  using SafeMathUpgradeable for uint256;
+  using SafeERC20Upgradeable for IERC20Upgradeable;
+
+  struct CreatePoolArgument {
+    address tokenA;
+    address tokenB;
+    uint256 precisionA;
+    uint256 precisionB;
+    uint256 mintFee;
+    uint256 swapFee;
+    uint256 redeemFee;
+    uint256 A;
+  }
+
+  /**
+   * @dev This event is emitted when the governance is modified.
+   * @param governance is the new value of the governance.
+   */
+  event GovernanceModified(address governance);
+
+  /**
+   * @dev This event is emitted when the governance is modified.
+   * @param governance is the new value of the governance.
+   */
+  event GovernanceProposed(address governance);
+
+  /**
+   * @dev This event is emitted when a new pool is created.
+   * @param poolToken is the pool token created.
+   */
+  event PoolCreated(address proxyAdmin, address poolToken, address stableAsset);
+
+  /**
+   * @dev This is the account that has governance control over the StableAssetApplication contract.
+   */
+  address public governance;
+
+  /**
+   * @dev Pending governance address,
+   */
+  address public pendingGovernance;
+
+  address public stableAssetImplentation;
+  address public tapETHImplentation;
+  ConstantExchangeRateProvider public constantExchangeRateProvider;
+
+  /**
+   * @dev Initializes the StableSwap Application contract.
+   */
+  function initialize(
+    address _stableAssetImplentation,
+    address _tapETHImplentation
+  ) public initializer {
+    __ReentrancyGuard_init();
+    governance = msg.sender;
+    stableAssetImplentation = _stableAssetImplentation;
+    tapETHImplentation = _tapETHImplentation;
+    constantExchangeRateProvider = new ConstantExchangeRateProvider();
+  }
+
+  /**
+   * @dev Propose the govenance address.
+   * @param _governance Address of the new governance.
+   */
+  function proposeGovernance(address _governance) public {
+    require(msg.sender == governance, "not governance");
+    pendingGovernance = _governance;
+    emit GovernanceProposed(_governance);
+  }
+
+  /**
+   * @dev Accept the govenance address.
+   */
+  function acceptGovernance() public {
+    require(msg.sender == pendingGovernance, "not pending governance");
+    governance = pendingGovernance;
+    pendingGovernance = address(0);
+    emit GovernanceModified(governance);
+  }
+
+  function createPool(CreatePoolArgument calldata argument) public {
+    ProxyAdmin proxyAdmin = new ProxyAdmin();
+    proxyAdmin.transferOwnership(msg.sender);
+    bytes memory tapETHInit = abi.encodeCall(
+      TapETH.initialize,
+      (address(this))
+    );
+    TransparentUpgradeableProxy tapETHProxy = new TransparentUpgradeableProxy(
+      address(tapETHImplentation),
+      address(proxyAdmin),
+      tapETHInit
+    );
+
+    address[] memory tokens = new address[](2);
+    uint256[] memory precisions = new uint256[](2);
+    uint256[] memory fees = new uint256[](3);
+    tokens[0] = argument.tokenA;
+    tokens[1] = argument.tokenB;
+    precisions[0] = argument.precisionA;
+    precisions[1] = argument.precisionB;
+    fees[0] = argument.mintFee;
+    fees[1] = argument.swapFee;
+    fees[2] = argument.redeemFee;
+    uint256 A = argument.A;
+    uint256 exchangeRateTokenIndex = 1;
+
+    bytes memory stableAssetInit = abi.encodeCall(
+      StableAsset.initialize,
+      (
+        tokens,
+        precisions,
+        fees,
+        TapETH(address(tapETHProxy)),
+        A,
+        constantExchangeRateProvider,
+        exchangeRateTokenIndex
+      )
+    );
+    TransparentUpgradeableProxy stableAssetProxy = new TransparentUpgradeableProxy(
+        address(stableAssetImplentation),
+        address(proxyAdmin),
+        stableAssetInit
+      );
+    StableAsset stableAsset = StableAsset(address(stableAssetProxy));
+    TapETH tapETH = TapETH(address(tapETHProxy));
+
+    stableAsset.proposeGovernance(msg.sender);
+    tapETH.addPool(address(stableAsset));
+    tapETH.proposeGovernance(msg.sender);
+    emit PoolCreated(
+      address(proxyAdmin),
+      address(tapETHProxy),
+      address(stableAssetProxy)
+    );
+  }
+}
diff --git a/docs/contracts/StableAsset.md b/docs/contracts/StableAsset.md
index 030a9ae..7d416a2 100644
--- a/docs/contracts/StableAsset.md
+++ b/docs/contracts/StableAsset.md
@@ -104,23 +104,6 @@ function exchangeRateTokenIndex() external view returns (uint256)
 *Index of tokens array for IExchangeRateProvider.*
 
 
-#### Returns
-
-| Name | Type | Description |
-|---|---|---|
-| _0 | uint256 | undefined |
-
-### feeErrorMargin
-
-```solidity
-function feeErrorMargin() external view returns (uint256)
-```
-
-
-
-*Fee error margin.*
-
-
 #### Returns
 
 | Name | Type | Description |
@@ -386,23 +369,6 @@ function initialize(address[] _tokens, uint256[] _precisions, uint256[] _fees, c
 | _exchangeRateProvider | contract IExchangeRateProvider | undefined |
 | _exchangeRateTokenIndex | uint256 | undefined |
 
-### maxDeltaD
-
-```solidity
-function maxDeltaD() external view returns (uint256)
-```
-
-
-
-*Max delta D.*
-
-
-#### Returns
-
-| Name | Type | Description |
-|---|---|---|
-| _0 | uint256 | undefined |
-
 ### mint
 
 ```solidity
@@ -821,71 +787,6 @@ function updateA(uint256 _futureA, uint256 _futureABlock) external nonpayable
 | _futureA | uint256 | The new A value. |
 | _futureABlock | uint256 | The block number to update A value. |
 
-### updateFeeErrorMargin
-
-```solidity
-function updateFeeErrorMargin(uint256 newValue) external nonpayable
-```
-
-
-
-*update fee error margin.*
-
-#### Parameters
-
-| Name | Type | Description |
-|---|---|---|
-| newValue | uint256 | undefined |
-
-### updateMaxDeltaDMargin
-
-```solidity
-function updateMaxDeltaDMargin(uint256 newValue) external nonpayable
-```
-
-
-
-*update yield error margin.*
-
-#### Parameters
-
-| Name | Type | Description |
-|---|---|---|
-| newValue | uint256 | undefined |
-
-### updateYieldErrorMargin
-
-```solidity
-function updateYieldErrorMargin(uint256 newValue) external nonpayable
-```
-
-
-
-*update yield error margin.*
-
-#### Parameters
-
-| Name | Type | Description |
-|---|---|---|
-| newValue | uint256 | undefined |
-
-### yieldErrorMargin
-
-```solidity
-function yieldErrorMargin() external view returns (uint256)
-```
-
-
-
-*Yield error margin.*
-
-
-#### Returns
-
-| Name | Type | Description |
-|---|---|---|
-| _0 | uint256 | undefined |
-
 
 
 ## Events
@@ -924,22 +825,6 @@ event FeeCollected(uint256 feeAmount, uint256 totalSupply)
 | feeAmount  | uint256 | is the amount of fee collected. |
 | totalSupply  | uint256 | is the total supply of LP token. |
 
-### FeeMarginModified
-
-```solidity
-event FeeMarginModified(uint256 margin)
-```
-
-
-
-*This event is emitted when the fee margin is modified.*
-
-#### Parameters
-
-| Name | Type | Description |
-|---|---|---|
-| margin  | uint256 | is the new value of the margin. |
-
 ### GovernanceModified
 
 ```solidity
@@ -988,22 +873,6 @@ event Initialized(uint8 version)
 |---|---|---|
 | version  | uint8 | undefined |
 
-### MaxDeltaDModified
-
-```solidity
-event MaxDeltaDModified(uint256 delta)
-```
-
-
-
-*This event is emitted when the max delta D is modified.*
-
-#### Parameters
-
-| Name | Type | Description |
-|---|---|---|
-| delta  | uint256 | is the new value of the delta. |
-
 ### MintFeeModified
 
 ```solidity
@@ -1128,43 +997,10 @@ event YieldCollected(uint256[] amounts, uint256 feeAmount, uint256 totalSupply)
 | feeAmount  | uint256 | is the amount of yield collected. |
 | totalSupply  | uint256 | is the total supply of LP token. |
 
-### YieldMarginModified
-
-```solidity
-event YieldMarginModified(uint256 margin)
-```
-
-
-
-*This event is emitted when the fee margin is modified.*
-
-#### Parameters
-
-| Name | Type | Description |
-|---|---|---|
-| margin  | uint256 | is the new value of the margin. |
-
 
 
 ## Errors
 
-### ImbalancedPool
-
-```solidity
-error ImbalancedPool(uint256 oldD, uint256 newD)
-```
-
-
-
-
-
-#### Parameters
-
-| Name | Type | Description |
-|---|---|---|
-| oldD | uint256 | undefined |
-| newD | uint256 | undefined |
-
 ### InsufficientMintAmount
 
 ```solidity
diff --git a/docs/contracts/elin/contracts/interfaces/IERC1822Proxiable.md b/docs/contracts/elin/contracts/interfaces/IERC1822Proxiable.md
new file mode 100644
index 0000000..c7220d8
--- /dev/null
+++ b/docs/contracts/elin/contracts/interfaces/IERC1822Proxiable.md
@@ -0,0 +1,32 @@
+# IERC1822Proxiable
+
+
+
+
+
+
+
+*ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified proxy whose upgrades are fully controlled by the current implementation.*
+
+## Methods
+
+### proxiableUUID
+
+```solidity
+function proxiableUUID() external view returns (bytes32)
+```
+
+
+
+*Returns the storage slot that the proxiable contract assumes is being used to store the implementation address. IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this function revert if invoked through a proxy.*
+
+
+#### Returns
+
+| Name | Type | Description |
+|---|---|---|
+| _0 | bytes32 | undefined |
+
+
+
+
diff --git a/docs/contracts/elin/contracts/interfaces/IERC1967.md b/docs/contracts/elin/contracts/interfaces/IERC1967.md
new file mode 100644
index 0000000..01698f3
--- /dev/null
+++ b/docs/contracts/elin/contracts/interfaces/IERC1967.md
@@ -0,0 +1,64 @@
+# IERC1967
+
+
+
+
+
+
+
+*ERC-1967: Proxy Storage Slots. This interface contains the events defined in the ERC. _Available since v4.8.3._*
+
+
+## Events
+
+### AdminChanged
+
+```solidity
+event AdminChanged(address previousAdmin, address newAdmin)
+```
+
+
+
+*Emitted when the admin account has changed.*
+
+#### Parameters
+
+| Name | Type | Description |
+|---|---|---|
+| previousAdmin  | address | undefined |
+| newAdmin  | address | undefined |
+
+### BeaconUpgraded
+
+```solidity
+event BeaconUpgraded(address indexed beacon)
+```
+
+
+
+*Emitted when the beacon is changed.*
+
+#### Parameters
+
+| Name | Type | Description |
+|---|---|---|
+| beacon `indexed` | address | undefined |
+
+### Upgraded
+
+```solidity
+event Upgraded(address indexed implementation)
+```
+
+
+
+*Emitted when the implementation is upgraded.*
+
+#### Parameters
+
+| Name | Type | Description |
+|---|---|---|
+| implementation `indexed` | address | undefined |
+
+
+
diff --git a/test/StableAssetFactory.ts b/test/StableAssetFactory.ts
new file mode 100644
index 0000000..b13704e
--- /dev/null
+++ b/test/StableAssetFactory.ts
@@ -0,0 +1,64 @@
+import { loadFixture } from "@nomicfoundation/hardhat-network-helpers";
+import { expect } from "chai";
+import { ethers, upgrades, web3 } from "hardhat";
+
+describe("StableAssetFactory", function () {
+  it("create pool", async () => {
+    const StableAssetFactory = await ethers.getContractFactory("StableAssetFactory");
+    const StableAsset = await ethers.getContractFactory("StableAsset");
+    const TapETH = await ethers.getContractFactory("TapETH");
+    const stableAssetImpl = await StableAsset.deploy();
+    const tapETHImpl = await TapETH.deploy();
+
+    /// Deploy swap and tokens
+    const factory = await upgrades.deployProxy(StableAssetFactory, [stableAssetImpl.address, tapETHImpl.address]);
+    const MockToken = await ethers.getContractFactory("MockToken");
+    /// Deploy token1 with name "test 1", symbol "T1", decimals 18
+    const token1 = await MockToken.deploy("test 1", "T1", 18);
+    /// Deploy token2 with name "test 2", symbol "T2", decimals 18
+    const token2 = await MockToken.deploy("test 2", "T2", 18);
+    const [owner, feeRecipient, user] = await ethers.getSigners();
+
+    const args = {
+      tokenA: token1.address,
+      tokenB: token2.address,
+      precisionA: 1,
+      precisionB: 1,
+      mintFee: 0,
+      swapFee: 0,
+      redeemFee: 0,
+      A: 100,
+    }
+
+    const tx = await factory.createPool(args);
+    const receipt = await tx.wait();
+    const event = receipt.events?.filter((x) => {
+      return x.event == "PoolCreated"
+    });
+    const poolToken = event[0].args.poolToken;
+    const stableAsset = event[0].args.stableAsset;
+
+    const poolTokenDeployed = TapETH.attach(poolToken);
+    const stableAssetDeployed = StableAsset.attach(stableAsset);
+    await poolTokenDeployed.acceptGovernance();
+    await stableAssetDeployed.acceptGovernance();
+
+    await stableAssetDeployed.unpause();
+    /// Mint 100 token1 to user
+    await token1.mint(user.address, web3.utils.toWei("100"));
+    /// Mint 100 token2 to user
+    await token2.mint(user.address, web3.utils.toWei("100"));
+    /// Approve swap contract to spend 100 token1
+    await token1.connect(user).approve(stableAssetDeployed.address, web3.utils.toWei("100"));
+    /// Approve swap contract to spend 100 token2
+    await token2.connect(user).approve(stableAssetDeployed.address, web3.utils.toWei("100"));
+
+    await stableAssetDeployed.connect(user).mint([web3.utils.toWei("100"),
+      web3.utils.toWei("100"),], 0);
+
+    console.log(await poolTokenDeployed.decimals());
+    console.log(await poolTokenDeployed.name());
+    console.log(await poolTokenDeployed.totalSupply());
+    console.log(await stableAssetDeployed.totalSupply());
+  });
+});