diff --git a/.doc/development-guide.md b/.doc/development-guide.md
new file mode 100644
index 0000000..b958277
--- /dev/null
+++ b/.doc/development-guide.md
@@ -0,0 +1,44 @@
+# Development Guide
+
+
+## Verify source code of deployed Contracts
+
+1. Create an account in polygonscan.com
+2. Create un API Key in your Polygon's account
+3. Copy your API Key from Polygonscan
+4. Create a .env file with the API Key
+
+```sh
+POLYGON_MUMBAI_RPC_PROVIDER = 'RPC Node URL'
+PRIVATE_KEY = 'your wallet private key'
+POLYGONSCAN_API_KEY = 'your polygonscan api key'
+```
+
+5. Install hardhat-etherscan dependency
+
+
+```sh
+npm install --save-dev @nomiclabs/hardhat-etherscan
+or 
+yarn add --dev @nomiclabs/hardhat-etherscan
+```
+
+6. Update your hardhat.config.js with etherscan
+
+
+```sh
+module.exports = {
+        solidity: ...
+        defaultNetwork: ...
+        networks: { ...}
+        etherscan: {
+           apiKey: POLYGONSCAN_API_KEY
+        }
+}
+```
+
+7. Verify the deployed contract address
+
+```sh
+npx hardhat verify CONTRACT_ADDR --network polygon
+```
diff --git a/hardhat.config.ts b/hardhat.config.ts
index 387ca78..cdf4e62 100644
--- a/hardhat.config.ts
+++ b/hardhat.config.ts
@@ -9,6 +9,7 @@ const INFURA_API_KEY = process.env.INFURA_API_KEY || 'INFURA_API_KEY'
 const ALCHEMY_API_KEY = process.env.ALCHEMY_API_KEY || 'ALCHEMY_API_KEY'
 const PRIVATE_KEY = process.env.PRIVATE_KEY
 const MNEMONIC = process.env.MNEMONIC
+const POLYGONSCAN_KEY = process.env.POLYGONSCAN_API_KEY || ''
 const solidityVersions = ["0.6.0", "0.6.2", "0.6.6", "0.8.18", "0.8.20"]
 const compilers = solidityVersions.map((version) => ({
   version,
@@ -72,6 +73,13 @@ const config: HardhatUserConfig = {
     tests: './test',
     cache: './cache',
     artifacts: './artifacts'
+  },
+  etherscan: {
+    // your API Key from PolygonScan
+    // Obtain one at https://polygonscan.com/
+    apiKey: {
+      polygon: POLYGONSCAN_KEY
+    }
   }
 }
 
diff --git a/package-lock.json b/package-lock.json
index b566d6d..d566820 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -17,7 +17,7 @@
         "@nomicfoundation/hardhat-network-helpers": "^1.0.0",
         "@nomicfoundation/hardhat-toolbox": "^2.0.0",
         "@nomiclabs/hardhat-ethers": "^2.0.0",
-        "@nomiclabs/hardhat-etherscan": "^3.0.0",
+        "@nomiclabs/hardhat-etherscan": "^3.1.8",
         "@openzeppelin/contracts": "^4.9.5",
         "@openzeppelin/hardhat-upgrades": "^1.28.0",
         "@typechain/ethers-v5": "^10.1.0",
@@ -36,6 +36,7 @@
         "hardhat-ignore-warnings": "^0.2.9",
         "prettier": "^3.1.0",
         "prettier-plugin-solidity": "^1.2.0",
+        "sol-merger": "^4.4.1",
         "solhint": "^4.0.0",
         "solidity-coverage": "^0.8.5",
         "ts-node": "^10.9.1",
@@ -2045,9 +2046,10 @@
       }
     },
     "node_modules/@nomiclabs/hardhat-etherscan": {
-      "version": "3.1.7",
-      "resolved": "https://registry.npmjs.org/@nomiclabs/hardhat-etherscan/-/hardhat-etherscan-3.1.7.tgz",
-      "integrity": "sha512-tZ3TvSgpvsQ6B6OGmo1/Au6u8BrAkvs1mIC/eURA3xgIfznUZBhmpne8hv7BXUzw9xNL3fXdpOYgOQlVMTcoHQ==",
+      "version": "3.1.8",
+      "resolved": "https://registry.npmjs.org/@nomiclabs/hardhat-etherscan/-/hardhat-etherscan-3.1.8.tgz",
+      "integrity": "sha512-v5F6IzQhrsjHh6kQz4uNrym49brK9K5bYCq2zQZ729RYRaifI9hHbtmK+KkIVevfhut7huQFEQ77JLRMAzWYjQ==",
+      "deprecated": "The @nomiclabs/hardhat-etherscan package is deprecated, please use @nomicfoundation/hardhat-verify instead",
       "dev": true,
       "dependencies": {
         "@ethersproject/abi": "^5.1.2",
@@ -3668,6 +3670,22 @@
         "node": ">=6"
       }
     },
+    "node_modules/cli-color": {
+      "version": "2.0.4",
+      "resolved": "https://registry.npmjs.org/cli-color/-/cli-color-2.0.4.tgz",
+      "integrity": "sha512-zlnpg0jNcibNrO7GG9IeHH7maWFeCz+Ja1wx/7tZNU5ASSSSZ+/qZciM0/LHCYxSdqv5h2sdbQ/PXYdOuetXvA==",
+      "dev": true,
+      "dependencies": {
+        "d": "^1.0.1",
+        "es5-ext": "^0.10.64",
+        "es6-iterator": "^2.0.3",
+        "memoizee": "^0.4.15",
+        "timers-ext": "^0.1.7"
+      },
+      "engines": {
+        "node": ">=0.10"
+      }
+    },
     "node_modules/cli-table3": {
       "version": "0.5.1",
       "resolved": "https://registry.npmjs.org/cli-table3/-/cli-table3-0.5.1.tgz",
@@ -4145,6 +4163,19 @@
         "node": "*"
       }
     },
+    "node_modules/d": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/d/-/d-1.0.2.tgz",
+      "integrity": "sha512-MOqHvMWF9/9MX6nza0KgvFH4HpMU0EF5uUDXqX/BtxtU8NfB0QzRtJ8Oe/6SuS4kbhyzVJwjd97EA4PKrzJ8bw==",
+      "dev": true,
+      "dependencies": {
+        "es5-ext": "^0.10.64",
+        "type": "^2.7.2"
+      },
+      "engines": {
+        "node": ">=0.12"
+      }
+    },
     "node_modules/dargs": {
       "version": "7.0.0",
       "resolved": "https://registry.npmjs.org/dargs/-/dargs-7.0.0.tgz",
@@ -4569,6 +4600,58 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/es5-ext": {
+      "version": "0.10.64",
+      "resolved": "https://registry.npmjs.org/es5-ext/-/es5-ext-0.10.64.tgz",
+      "integrity": "sha512-p2snDhiLaXe6dahss1LddxqEm+SkuDvV8dnIQG0MWjyHpcMNfXKPE+/Cc0y+PhxJX3A4xGNeFCj5oc0BUh6deg==",
+      "dev": true,
+      "hasInstallScript": true,
+      "dependencies": {
+        "es6-iterator": "^2.0.3",
+        "es6-symbol": "^3.1.3",
+        "esniff": "^2.0.1",
+        "next-tick": "^1.1.0"
+      },
+      "engines": {
+        "node": ">=0.10"
+      }
+    },
+    "node_modules/es6-iterator": {
+      "version": "2.0.3",
+      "resolved": "https://registry.npmjs.org/es6-iterator/-/es6-iterator-2.0.3.tgz",
+      "integrity": "sha512-zw4SRzoUkd+cl+ZoE15A9o1oQd920Bb0iOJMQkQhl3jNc03YqVjAhG7scf9C5KWRU/R13Orf588uCC6525o02g==",
+      "dev": true,
+      "dependencies": {
+        "d": "1",
+        "es5-ext": "^0.10.35",
+        "es6-symbol": "^3.1.1"
+      }
+    },
+    "node_modules/es6-symbol": {
+      "version": "3.1.4",
+      "resolved": "https://registry.npmjs.org/es6-symbol/-/es6-symbol-3.1.4.tgz",
+      "integrity": "sha512-U9bFFjX8tFiATgtkJ1zg25+KviIXpgRvRHS8sau3GfhVzThRQrOeksPeT0BWW2MNZs1OEWJ1DPXOQMn0KKRkvg==",
+      "dev": true,
+      "dependencies": {
+        "d": "^1.0.2",
+        "ext": "^1.7.0"
+      },
+      "engines": {
+        "node": ">=0.12"
+      }
+    },
+    "node_modules/es6-weak-map": {
+      "version": "2.0.3",
+      "resolved": "https://registry.npmjs.org/es6-weak-map/-/es6-weak-map-2.0.3.tgz",
+      "integrity": "sha512-p5um32HOTO1kP+w7PRnB+5lQ43Z6muuMuIMffvDN8ZB4GcnjLBV6zGStpbASIMk4DCAvEaamhe2zhyCb/QXXsA==",
+      "dev": true,
+      "dependencies": {
+        "d": "1",
+        "es5-ext": "^0.10.46",
+        "es6-iterator": "^2.0.3",
+        "es6-symbol": "^3.1.1"
+      }
+    },
     "node_modules/escalade": {
       "version": "3.1.1",
       "resolved": "https://registry.npmjs.org/escalade/-/escalade-3.1.1.tgz",
@@ -4789,6 +4872,21 @@
       "integrity": "sha512-xbbCH5dCYU5T8LcEhhuh7HJ88HXuW3qsI3Y0zOZFKfZEHcpWiHU/Jxzk629Brsab/mMiHQti9wMP+845RPe3Vg==",
       "dev": true
     },
+    "node_modules/esniff": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/esniff/-/esniff-2.0.1.tgz",
+      "integrity": "sha512-kTUIGKQ/mDPFoJ0oVfcmyJn4iBDRptjNVIzwIFR7tqWXdVI9xfA2RMwY/gbSpJG3lkdWNEjLap/NqVHZiJsdfg==",
+      "dev": true,
+      "dependencies": {
+        "d": "^1.0.1",
+        "es5-ext": "^0.10.62",
+        "event-emitter": "^0.3.5",
+        "type": "^2.7.2"
+      },
+      "engines": {
+        "node": ">=0.10"
+      }
+    },
     "node_modules/espree": {
       "version": "9.6.1",
       "resolved": "https://registry.npmjs.org/espree/-/espree-9.6.1.tgz",
@@ -5117,6 +5215,16 @@
         "npm": ">=3"
       }
     },
+    "node_modules/event-emitter": {
+      "version": "0.3.5",
+      "resolved": "https://registry.npmjs.org/event-emitter/-/event-emitter-0.3.5.tgz",
+      "integrity": "sha512-D9rRn9y7kLPnJ+hMq7S/nhvoKwwvVJahBi2BPmx3bvbsEdK3W9ii8cBSGjP+72/LnM4n6fo3+dkCX5FeTQruXA==",
+      "dev": true,
+      "dependencies": {
+        "d": "1",
+        "es5-ext": "~0.10.14"
+      }
+    },
     "node_modules/evp_bytestokey": {
       "version": "1.0.3",
       "resolved": "https://registry.npmjs.org/evp_bytestokey/-/evp_bytestokey-1.0.3.tgz",
@@ -5150,6 +5258,15 @@
         "url": "https://github.com/sindresorhus/execa?sponsor=1"
       }
     },
+    "node_modules/ext": {
+      "version": "1.7.0",
+      "resolved": "https://registry.npmjs.org/ext/-/ext-1.7.0.tgz",
+      "integrity": "sha512-6hxeJYaL110a9b5TEJSj0gojyHQAmA2ch5Os+ySCiA1QGdS697XWY1pzsrSjqA9LDEEgdB/KypIlR59RcLuHYw==",
+      "dev": true,
+      "dependencies": {
+        "type": "^2.7.2"
+      }
+    },
     "node_modules/fast-base64-decode": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/fast-base64-decode/-/fast-base64-decode-1.0.0.tgz",
@@ -6877,6 +6994,12 @@
         "node": ">=8"
       }
     },
+    "node_modules/is-promise": {
+      "version": "2.2.2",
+      "resolved": "https://registry.npmjs.org/is-promise/-/is-promise-2.2.2.tgz",
+      "integrity": "sha512-+lP4/6lKUBfQjZ2pdxThZvLUAafmZb8OAxFb8XXtiQmS35INgr85hdOGoEs124ez1FCnZJt6jau/T+alh58QFQ==",
+      "dev": true
+    },
     "node_modules/is-regex": {
       "version": "1.1.4",
       "resolved": "https://registry.npmjs.org/is-regex/-/is-regex-1.1.4.tgz",
@@ -7402,6 +7525,15 @@
         "yallist": "^3.0.2"
       }
     },
+    "node_modules/lru-queue": {
+      "version": "0.1.0",
+      "resolved": "https://registry.npmjs.org/lru-queue/-/lru-queue-0.1.0.tgz",
+      "integrity": "sha512-BpdYkt9EvGl8OfWHDQPISVpcl5xZthb+XPsbELj5AQXxIC8IriDZIQYjBJPEm5rS420sjZ0TLEzRcq5KdBhYrQ==",
+      "dev": true,
+      "dependencies": {
+        "es5-ext": "~0.10.2"
+      }
+    },
     "node_modules/make-error": {
       "version": "1.3.6",
       "resolved": "https://registry.npmjs.org/make-error/-/make-error-1.3.6.tgz",
@@ -7446,6 +7578,22 @@
         "safe-buffer": "^5.1.2"
       }
     },
+    "node_modules/memoizee": {
+      "version": "0.4.15",
+      "resolved": "https://registry.npmjs.org/memoizee/-/memoizee-0.4.15.tgz",
+      "integrity": "sha512-UBWmJpLZd5STPm7PMUlOw/TSy972M+z8gcyQ5veOnSDRREz/0bmpyTfKt3/51DhEBqCZQn1udM/5flcSPYhkdQ==",
+      "dev": true,
+      "dependencies": {
+        "d": "^1.0.1",
+        "es5-ext": "^0.10.53",
+        "es6-weak-map": "^2.0.3",
+        "event-emitter": "^0.3.5",
+        "is-promise": "^2.2.2",
+        "lru-queue": "^0.1.0",
+        "next-tick": "^1.1.0",
+        "timers-ext": "^0.1.7"
+      }
+    },
     "node_modules/memory-level": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/memory-level/-/memory-level-1.0.0.tgz",
@@ -7831,6 +7979,12 @@
       "integrity": "sha512-Yd3UES5mWCSqR+qNT93S3UoYUkqAZ9lLg8a7g9rimsWmYGK8cVToA4/sF3RrshdyV3sAGMXVUmpMYOw+dLpOuw==",
       "dev": true
     },
+    "node_modules/next-tick": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/next-tick/-/next-tick-1.1.0.tgz",
+      "integrity": "sha512-CXdUiJembsNjuToQvxayPZF9Vqht7hewsvy2sOWafLvi2awflj9mOC6bHIg50orX8IJvWKY9wYQ/zB2kogPslQ==",
+      "dev": true
+    },
     "node_modules/node-addon-api": {
       "version": "2.0.2",
       "resolved": "https://registry.npmjs.org/node-addon-api/-/node-addon-api-2.0.2.tgz",
@@ -9375,6 +9529,50 @@
         "node": ">=8"
       }
     },
+    "node_modules/sol-merger": {
+      "version": "4.4.1",
+      "resolved": "https://registry.npmjs.org/sol-merger/-/sol-merger-4.4.1.tgz",
+      "integrity": "sha512-t/AMUQOLdYgVTHPB6vA+InqYxABxV6YJlts87QxIQcG5zqNyGGygQKRbHImi+TufldFAINHXRPdXsRndPYvx1A==",
+      "dev": true,
+      "dependencies": {
+        "antlr4ts": "^0.5.0-alpha.4",
+        "cli-color": "^2.0.3",
+        "commander": "^4.0.1",
+        "debug": "^4.3.4",
+        "fs-extra": "^10.0.0",
+        "glob": "^7.1.7",
+        "strip-json-comments": "^3.0.1"
+      },
+      "bin": {
+        "sol-merger": "dist/bin/sol-merger.js"
+      },
+      "engines": {
+        "node": ">=14.0.0"
+      }
+    },
+    "node_modules/sol-merger/node_modules/commander": {
+      "version": "4.1.1",
+      "resolved": "https://registry.npmjs.org/commander/-/commander-4.1.1.tgz",
+      "integrity": "sha512-NOKm8xhkzAjzFx8B2v5OAHT+u5pRQc2UCa2Vq9jYL/31o2wi9mxBA7LIFs3sV5VSC49z6pEhfbMULvShKj26WA==",
+      "dev": true,
+      "engines": {
+        "node": ">= 6"
+      }
+    },
+    "node_modules/sol-merger/node_modules/fs-extra": {
+      "version": "10.1.0",
+      "resolved": "https://registry.npmjs.org/fs-extra/-/fs-extra-10.1.0.tgz",
+      "integrity": "sha512-oRXApq54ETRj4eMiFzGnHWGy+zo5raudjuxN0b8H7s/RU2oW0Wvsx9O0ACRN/kRq9E8Vu/ReskGB5o3ji+FzHQ==",
+      "dev": true,
+      "dependencies": {
+        "graceful-fs": "^4.2.0",
+        "jsonfile": "^6.0.1",
+        "universalify": "^2.0.0"
+      },
+      "engines": {
+        "node": ">=12"
+      }
+    },
     "node_modules/solc": {
       "version": "0.7.3",
       "resolved": "https://registry.npmjs.org/solc/-/solc-0.7.3.tgz",
@@ -10354,6 +10552,16 @@
         "readable-stream": "3"
       }
     },
+    "node_modules/timers-ext": {
+      "version": "0.1.7",
+      "resolved": "https://registry.npmjs.org/timers-ext/-/timers-ext-0.1.7.tgz",
+      "integrity": "sha512-b85NUNzTSdodShTIbky6ZF02e8STtVVfD+fu4aXXShEELpozH+bCpJLYMPZbsABN2wDH7fJpqIoXxJpzbf0NqQ==",
+      "dev": true,
+      "dependencies": {
+        "es5-ext": "~0.10.46",
+        "next-tick": "1"
+      }
+    },
     "node_modules/tmp": {
       "version": "0.0.33",
       "resolved": "https://registry.npmjs.org/tmp/-/tmp-0.0.33.tgz",
@@ -10502,6 +10710,12 @@
       "integrity": "sha512-RKJBIj8lySrShN4w6i/BonWp2Z/uxwC3h4y7xsRrpP59ZboCd0GpEVsOnMDYLMmKBpYhb5TgHzZXy7wTfYFBRw==",
       "dev": true
     },
+    "node_modules/type": {
+      "version": "2.7.2",
+      "resolved": "https://registry.npmjs.org/type/-/type-2.7.2.tgz",
+      "integrity": "sha512-dzlvlNlt6AXU7EBSfpAscydQ7gXB+pPGsPnfJnZpiNJBDj7IaJzQlBZYGdEi4R9HmPdBv2XmWJ6YUtoTa7lmCw==",
+      "dev": true
+    },
     "node_modules/type-check": {
       "version": "0.4.0",
       "resolved": "https://registry.npmjs.org/type-check/-/type-check-0.4.0.tgz",
diff --git a/package.json b/package.json
index 6588152..9b42934 100644
--- a/package.json
+++ b/package.json
@@ -17,7 +17,8 @@
     "prettier": "npx prettier --log-level warn --ignore-path .gitignore \"{contracts,test}/**/*.{js,ts,.sol}\" --check",
     "prettier:fix": "npx prettier --log-level warn --ignore-path .gitignore \"{contracts,test}/**/*.{js,ts,.sol}\" --write",
     "slither": "slither . --filter-paths \" *v1.sol\"",
-    "commitlint-check-comit-msg": "npx --no-install commitlint --edit \"$1\""
+    "commitlint-check-comit-msg": "npx --no-install commitlint --edit \"$1\"",
+    "merge-contracts": "sol-merger \"./contracts/**/*.sol\" ./build"
   },
   "devDependencies": {
     "@commitlint/cli": "^18.4.3",
@@ -28,7 +29,7 @@
     "@nomicfoundation/hardhat-network-helpers": "^1.0.0",
     "@nomicfoundation/hardhat-toolbox": "^2.0.0",
     "@nomiclabs/hardhat-ethers": "^2.0.0",
-    "@nomiclabs/hardhat-etherscan": "^3.0.0",
+    "@nomiclabs/hardhat-etherscan": "^3.1.8",
     "@openzeppelin/contracts": "^4.9.5",
     "@openzeppelin/hardhat-upgrades": "^1.28.0",
     "@typechain/ethers-v5": "^10.1.0",
@@ -47,6 +48,7 @@
     "hardhat-ignore-warnings": "^0.2.9",
     "prettier": "^3.1.0",
     "prettier-plugin-solidity": "^1.2.0",
+    "sol-merger": "^4.4.1",
     "solhint": "^4.0.0",
     "solidity-coverage": "^0.8.5",
     "ts-node": "^10.9.1",