diff --git a/.gitignore b/.gitignore
index 985ef72..a5be68a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,8 @@
+# dependencies
+/node_modules
+/.pnp
+.pnp.js
+
 # dependencies (bun install)
 node_modules
 
@@ -47,4 +52,4 @@ lerna-debug.log*
 *.ntvs*
 *.njsproj
 *.sln
-*.sw?
+*.sw?
\ No newline at end of file
diff --git a/README.md b/README.md
index 9d5813d..d522a04 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,53 @@
+# Chain Indexer Notification and Leaderboard Builder API
+
+This API notifies a blockchain indexer about new submissions and triggers a leaderboard builder.
+
+## Features
+
+- Notify a chain indexer with submission data
+- Trigger a leaderboard update
+- Modular design with clear service responsibilities
+
+## Prerequisites
+
+- Node.js (v16+)
+- npm or yarn
+
+## Installation
+
+1. Clone the repository:
+    ```bash
+    git clone https://github.com/yourusername/backend.git
+    cd chain-notifier
+    ```
+
+2. Install dependencies:
+    npm install express
+    ```
+
+3. Create a `.env` file in the root directory for environment variables if required.
+
+## Usage
+
+1. Start the server:
+    node app.js
+    ```
+
+2. Use the `/api/notify` endpoint to notify the indexer and trigger the leaderboard.
+
+### Example Request
+**Endpoint**: `POST /api/notify`
+
+**Body**:
+```json
+{
+    "submissionData": {
+        "userId": "05421",
+        "submissionId": "fghij",
+        "score": 40
+    }
+}
+=======
 # DeCleanup Network Backend
 
 Backend API for the DeCleanup Network application, providing wallet-based
diff --git a/app.js b/app.js
new file mode 100644
index 0000000..9ec7653
--- /dev/null
+++ b/app.js
@@ -0,0 +1,19 @@
+const express = require('express');
+const apiRoutes = require('./routes/apiRoutes');
+
+const app = express();
+app.use(express.json());
+
+// Use API routes
+app.use('/api', apiRoutes);
+
+// Error handling middleware
+app.use((err, req, res, next) => {
+    console.error(err.stack);
+    res.status(500).json({ error: 'Something went wrong!' });
+});
+
+const PORT = process.env.PORT || 3000;
+app.listen(PORT, () => {
+    console.log(`Server running on port ${PORT}`);
+});
\ No newline at end of file
diff --git a/controllers/submissionController.js b/controllers/submissionController.js
new file mode 100644
index 0000000..00a30fc
--- /dev/null
+++ b/controllers/submissionController.js
@@ -0,0 +1,27 @@
+const { notifyIndexerService } = require('../services/indexerService');
+const { updateLeaderboard } = require('../services/leaderboardService');
+
+exports.notifyIndexer = async (req, res) => {
+    try {
+        const { submissionData } = req.body;
+
+        if (!submissionData) {
+            return res.status(400).json({ error: 'Submission data is required' });
+        }
+
+        // Notify the chain indexer
+        const indexerResponse = await notifyIndexerService(submissionData);
+
+        // Trigger the leaderboard builder
+        const leaderboardResponse = await updateLeaderboard();
+
+        res.status(200).json({
+            message: 'Indexer notified and leaderboard updated successfully.',
+            indexerResponse,
+            leaderboardResponse,
+        });
+    } catch (error) {
+        console.error(error);
+        res.status(500).json({ error: 'Failed to process the request.' });
+    }
+};
\ No newline at end of file
diff --git a/package-lock.json b/package-lock.json
index 1c5bbb4..a40bc3a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,9 +1,13 @@
 {
+  "name": "backend",
   "name": "decleanup-network_backend",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
+      "dependencies": {
+        "express": "^4.21.2"
+
       "name": "decleanup-network_backend",
       "dependencies": {
         "@wagmi/core": "^2.16.5",
@@ -1198,6 +1202,10 @@
         "node": ">= 0.6"
       }
     },
+    "node_modules/array-flatten": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/array-flatten/-/array-flatten-1.1.1.tgz",
+      "integrity": "sha512-PCVAQswWemu6UdxsDFFX/+gVeYqKAod3D3UVm91jHwynguOwAvYPhx8nNlM++NqRcK6CxxpUafjmhIdKiHibqg=="
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       "version": "4.0.0-beta.5",
       "resolved": "https://registry.npmjs.org/aes-js/-/aes-js-4.0.0-beta.5.tgz",
@@ -1289,6 +1297,10 @@
       }
     },
     "node_modules/call-bind-apply-helpers": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/call-bind-apply-helpers/-/call-bind-apply-helpers-1.0.1.tgz",
+      "integrity": "sha512-BhYE+WDaywFg2TBWYNXAE+8B1ATnThNBqXHP5nQu0jWJdVvY2hvkpyB3qOmtmDePiS5/BDQ8wASEWGMWRG148g==",
+
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/call-bind-apply-helpers/-/call-bind-apply-helpers-1.0.2.tgz",
       "integrity": "sha512-Sp1ablJ0ivDkSzjcaJdxEunN5/XvksFJ2sMBFfq6x0ryhQV/2b/KwFe21cMpmHtPOSij8K99/wSfoEuTObmuMQ==",
@@ -1302,6 +1314,12 @@
       }
     },
     "node_modules/call-bound": {
+      "version": "1.0.3",
+      "resolved": "https://registry.npmjs.org/call-bound/-/call-bound-1.0.3.tgz",
+      "integrity": "sha512-YTd+6wGlNlPxSuri7Y6X8tY2dmm12UMH66RpKMhiX6rsk5wXXnYgbUcOt8kiS31/AjfoTOvCsE+w8nZQLQnzHA==",
+      "dependencies": {
+        "call-bind-apply-helpers": "^1.0.1",
+        "get-intrinsic": "^1.2.6"
       "version": "1.0.4",
       "resolved": "https://registry.npmjs.org/call-bound/-/call-bound-1.0.4.tgz",
       "integrity": "sha512-+ys997U96po4Kx/ABpBCqhA9EuxJaQWDQg7295H4hBphv3IZg0boBKuwYpt4YXp6MZ5AmZQnU/tyMTlRpaSejg==",
@@ -1321,6 +1339,7 @@
       "version": "0.5.4",
       "resolved": "https://registry.npmjs.org/content-disposition/-/content-disposition-0.5.4.tgz",
       "integrity": "sha512-FveZTNuGw04cxlAiWbzi6zTAL/lhehaWbTtgluJh4/E95DqMwTmha3KZN1aAWA8cFIhHzMZUvLevkw5Rqk+tSQ==",
+
       "license": "MIT",
       "dependencies": {
         "safe-buffer": "5.2.1"
@@ -1350,6 +1369,14 @@
     "node_modules/cookie-signature": {
       "version": "1.0.6",
       "resolved": "https://registry.npmjs.org/cookie-signature/-/cookie-signature-1.0.6.tgz",
+      "integrity": "sha512-QADzlaHc8icV8I7vbaJXJwod9HWYp8uCqf1xa4OfNu1T7JVxQIrUgOWtHdNDtPiywmFbiS12VjotIXLrKM3orQ=="
+    },
+    "node_modules/debug": {
+      "version": "2.6.9",
+      "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
+      "integrity": "sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==",
+      "dependencies": {
+        "ms": "2.0.0"
       "integrity": "sha512-QADzlaHc8icV8I7vbaJXJwod9HWYp8uCqf1xa4OfNu1T7JVxQIrUgOWtHdNDtPiywmFbiS12VjotIXLrKM3orQ==",
       "license": "MIT"
     },
@@ -1565,6 +1592,11 @@
         "node": ">= 0.4"
       }
     },
+    "node_modules/ee-first": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/ee-first/-/ee-first-1.1.1.tgz",
+      "integrity": "sha512-WMwm9LhRUo+WUaRN+vRuETqG89IgZphVSNkdFgeb6sS/E4OrDIN7t48CAewSHXc6C8lefD8KKfr5vY61brQlow=="
+
     "node_modules/ecdsa-sig-formatter": {
       "version": "1.0.11",
       "resolved": "https://registry.npmjs.org/ecdsa-sig-formatter/-/ecdsa-sig-formatter-1.0.11.tgz",
@@ -1579,16 +1611,19 @@
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       "integrity": "sha512-WMwm9LhRUo+WUaRN+vRuETqG89IgZphVSNkdFgeb6sS/E4OrDIN7t48CAewSHXc6C8lefD8KKfr5vY61brQlow==",
       "license": "MIT"
+
     },
     "node_modules/encodeurl": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/encodeurl/-/encodeurl-2.0.0.tgz",
       "integrity": "sha512-Q0n9HRi4m6JuGIV1eFlmvJB7ZEVxu93IrMyiMsGC0lrMJMWzRgx6WGquyfQgZVb31vhGgXnfmPNNXmxnOkRBrg==",
+
       "license": "MIT",
       "engines": {
         "node": ">= 0.8"
       }
     },
+
     "node_modules/env-paths": {
       "version": "3.0.0",
       "resolved": "https://registry.npmjs.org/env-paths/-/env-paths-3.0.0.tgz",
@@ -1631,6 +1666,10 @@
         "node": ">= 0.4"
       }
     },
+    "node_modules/escape-html": {
+      "version": "1.0.3",
+      "resolved": "https://registry.npmjs.org/escape-html/-/escape-html-1.0.3.tgz",
+      "integrity": "sha512-NiSupZ4OeuGwr68lGIeym/ksIZMJodUGOSCZ/FSnTxcrekbvqrgdUxlJOMpijaKZVjAJrWrGs/6Jy8OMuyj9ow=="
     "node_modules/esbuild": {
       "version": "0.19.12",
       "resolved": "https://registry.npmjs.org/esbuild/-/esbuild-0.19.12.tgz",
@@ -1692,6 +1731,7 @@
       "resolved": "https://registry.npmjs.org/etag/-/etag-1.8.1.tgz",
       "integrity": "sha512-aIL5Fx7mawVa300al2BnEE4iNvo1qETxLrPI/o05L7z6go7fCw1J6EQmbK4FmJ2AS7kgVF/KEZWufBfdClMcPg==",
       "license": "MIT",
+
       "engines": {
         "node": ">= 0.6"
       }
@@ -1869,6 +1909,18 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/get-intrinsic": {
+      "version": "1.2.7",
+      "resolved": "https://registry.npmjs.org/get-intrinsic/-/get-intrinsic-1.2.7.tgz",
+      "integrity": "sha512-VW6Pxhsrk0KAOqs3WEd0klDiF/+V7gQOpAvY1jVU/LHmaD/kQO4523aiJuikX/QAKYiW6x8Jh+RJej1almdtCA==",
+      "dependencies": {
+        "call-bind-apply-helpers": "^1.0.1",
+        "es-define-property": "^1.0.1",
+        "es-errors": "^1.3.0",
+        "es-object-atoms": "^1.0.0",
+        "function-bind": "^1.1.2",
+        "get-proto": "^1.0.0",
+=======
     "node_modules/gel": {
       "version": "2.0.1",
       "resolved": "https://registry.npmjs.org/gel/-/gel-2.0.1.tgz",
@@ -2005,6 +2057,7 @@
     "node_modules/inherits": {
       "version": "2.0.4",
       "resolved": "https://registry.npmjs.org/inherits/-/inherits-2.0.4.tgz",
+      "integrity": "sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ=="
       "integrity": "sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ==",
       "license": "ISC"
     },
@@ -2195,6 +2248,10 @@
         "node": ">= 0.6"
       }
     },
+    "node_modules/ms": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/ms/-/ms-2.0.0.tgz",
+      "integrity": "sha512-Tpp60P6IUJDTuOq/5Z8cdskzJujfwqfOTkrwIwj7IRISpnkJnT6SyJ4PCPnGMoFjC9ddhal5KVIYtAt97ix05A=="
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@@ -2230,6 +2287,10 @@
         "node": ">= 0.6"
       }
     },
+    "node_modules/object-inspect": {
+      "version": "1.13.3",
+      "resolved": "https://registry.npmjs.org/object-inspect/-/object-inspect-1.13.3.tgz",
+      "integrity": "sha512-kDCGIbxkDSXE3euJZZXzc6to7fCrKHNI/hSRQnRuQ+BWjFNzZwiFF8fj/6o2t2G9/jTj8PSIYTfCLelLZEeRpA==",
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       "resolved": "https://registry.npmjs.org/object-assign/-/object-assign-4.1.1.tgz",
@@ -2338,6 +2399,7 @@
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       "version": "0.1.12",
       "resolved": "https://registry.npmjs.org/path-to-regexp/-/path-to-regexp-0.1.12.tgz",
+      "integrity": "sha512-RA1GjUVMnvYFxuqovrEqZoxxW5NUZqbwKtYz/Tt7nXerk0LbLblQmrsgdeOxV5SFHf0UDggjS/bSeOZwt1pmEQ=="
       "integrity": "sha512-RA1GjUVMnvYFxuqovrEqZoxxW5NUZqbwKtYz/Tt7nXerk0LbLblQmrsgdeOxV5SFHf0UDggjS/bSeOZwt1pmEQ==",
       "license": "MIT"
     },
@@ -2593,7 +2655,7 @@
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-      "license": "MIT",
+     "license": "MIT",
       "engines": {
         "node": ">= 0.6"
       }
@@ -2639,12 +2701,14 @@
           "type": "consulting",
           "url": "https://feross.org/support"
         }
+      ]
       ],
       "license": "MIT"
     },
     "node_modules/safer-buffer": {
       "version": "2.1.2",
       "resolved": "https://registry.npmjs.org/safer-buffer/-/safer-buffer-2.1.2.tgz",
+      "integrity": "sha512-YZo3K82SD7Riyi0E1EQPojLz7kpepnSQI9IyPbHHg1XXXevb5dJI7tpyN2ADxGcQbHG7vcyRHk0cbwqcQriUtg=="
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       "license": "MIT"
     },
@@ -2708,6 +2772,11 @@
         "node": ">= 0.8"
       }
     },
+    "node_modules/send/node_modules/ms": {
+      "version": "2.1.3",
+      "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.3.tgz",
+      "integrity": "sha512-6FlzubTLZG3J2a/NVCAleEhjzq5oxgHyaCU9yYXvcLsvoVaHJq/s5xXI6/XXP6tz7R9xAOtHnSO/tXtF3WRTlA=="
+    },
     "node_modules/serve-static": {
       "version": "1.16.2",
       "resolved": "https://registry.npmjs.org/serve-static/-/serve-static-1.16.2.tgz",
@@ -2726,6 +2795,7 @@
     "node_modules/setprototypeof": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/setprototypeof/-/setprototypeof-1.2.0.tgz",
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+      "engines": {
+        "node": ">= 0.8"
+      }
       "license": "MIT",
       "engines": {
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diff --git a/package.json b/package.json
index a52dc8d..a8b9fb2 100644
--- a/package.json
+++ b/package.json
@@ -1,4 +1,7 @@
 {
+  "dependencies": {
+    "express": "^4.21.2"
+  }
   "name": "decleanup-network_backend",
   "module": "index.ts",
   "type": "module",
diff --git a/routes/apiRoutes.js b/routes/apiRoutes.js
new file mode 100644
index 0000000..5f6e74b
--- /dev/null
+++ b/routes/apiRoutes.js
@@ -0,0 +1,8 @@
+const express = require('express');
+const { notifyIndexer } = require('../controllers/submissionController');
+const router = express.Router();
+
+// Endpoint to notify the indexer and trigger leaderboard update
+router.post('/notify', notifyIndexer);
+
+module.exports = router;
\ No newline at end of file
diff --git a/services/indexerService.js b/services/indexerService.js
new file mode 100644
index 0000000..49845c9
--- /dev/null
+++ b/services/indexerService.js
@@ -0,0 +1,12 @@
+exports.notifyIndexerService = async (submissionData) => {
+    try {
+        // Simulate notifying the blockchain indexer
+        console.log('Notifying chain indexer with submission:', submissionData);
+
+        // Simulate a successful response
+        return { status: 'success', message: 'Indexer notified.' };
+    } catch (error) {
+        console.error('Error notifying indexer:', error);
+        throw new Error('Failed to notify indexer.');
+    }
+};
\ No newline at end of file
diff --git a/services/leaderboardService.js b/services/leaderboardService.js
new file mode 100644
index 0000000..d0be6e3
--- /dev/null
+++ b/services/leaderboardService.js
@@ -0,0 +1,12 @@
+exports.updateLeaderboard = async () => {
+    try {
+        // Simulate leaderboard rebuilding
+        console.log('Rebuilding leaderboard...');
+
+        // Simulate a successful response
+        return { status: 'success', message: 'Leaderboard updated.' };
+    } catch (error) {
+        console.error('Error updating leaderboard:', error);
+        throw new Error('Failed to update leaderboard.');
+    }
+};
\ No newline at end of file