diff --git a/app/api/search/route.ts b/app/api/search/route.ts
index 5a3a179..f7e6a4d 100644
--- a/app/api/search/route.ts
+++ b/app/api/search/route.ts
@@ -1,6 +1,16 @@
 import { NextRequest, NextResponse } from 'next/server';
 import { esClient, INDEX_NAME, initializeIndex } from '@/lib/elasticsearch';
-import { generateHashes, detectHashType, isHash } from '@/lib/hash';
+import { generateHashes, detectHashType } from '@/lib/hash';
+
+interface HashDocument {
+  plaintext: string;
+  md5: string;
+  sha1: string;
+  sha256: string;
+  sha512: string;
+  bcrypt: string;
+  created_at?: string;
+}
 
 export async function POST(request: NextRequest) {
   try {
@@ -30,7 +40,7 @@ export async function POST(request: NextRequest) {
 
     if (hashType) {
       // Query is a hash - search for it in Elasticsearch
-      const searchResponse = await esClient.search({
+      const searchResponse = await esClient.search<HashDocument>({
         index: INDEX_NAME,
         query: {
           term: {
@@ -47,16 +57,19 @@ export async function POST(request: NextRequest) {
           found: true,
           hashType,
           hash: cleanQuery,
-          results: hits.map((hit: any) => ({
-            plaintext: hit._source.plaintext,
-            hashes: {
-              md5: hit._source.md5,
-              sha1: hit._source.sha1,
-              sha256: hit._source.sha256,
-              sha512: hit._source.sha512,
-              bcrypt: hit._source.bcrypt,
-            }
-          }))
+          results: hits.map((hit) => {
+            const source = hit._source!;
+            return {
+              plaintext: source.plaintext,
+              hashes: {
+                md5: source.md5,
+                sha1: source.sha1,
+                sha256: source.sha256,
+                sha512: source.sha512,
+                bcrypt: source.bcrypt,
+              }
+            };
+          })
         });
       } else {
         // Hash not found in database
@@ -69,20 +82,20 @@ export async function POST(request: NextRequest) {
       }
     } else {
       // Query is plaintext - check if it already exists first
-      const existsResponse = await esClient.search({
+      const existsResponse = await esClient.search<HashDocument>({
         index: INDEX_NAME,
         query: {
           term: {
             'plaintext.keyword': cleanQuery
           }
         }
-      } as any);
+      });
 
       let hashes;
 
       if (existsResponse.hits.hits.length > 0) {
         // Plaintext found, retrieve existing hashes
-        const existingDoc = existsResponse.hits.hits[0]._source as any;
+        const existingDoc = existsResponse.hits.hits[0]._source!;
         hashes = {
           md5: existingDoc.md5,
           sha1: existingDoc.sha1,
@@ -94,7 +107,7 @@ export async function POST(request: NextRequest) {
         // Plaintext not found, generate hashes and check if any hash already exists
         hashes = await generateHashes(cleanQuery);
         
-        const hashExistsResponse = await esClient.search({
+        const hashExistsResponse = await esClient.search<HashDocument>({
           index: INDEX_NAME,
           query: {
             bool: {
@@ -107,7 +120,7 @@ export async function POST(request: NextRequest) {
               minimum_should_match: 1
             }
           }
-        } as any);
+        });
 
         if (hashExistsResponse.hits.hits.length === 0) {
           // No duplicates found, insert new document
diff --git a/app/page.tsx b/app/page.tsx
index bfa7ebf..5bf3c90 100644
--- a/app/page.tsx
+++ b/app/page.tsx
@@ -58,7 +58,7 @@ export default function Home() {
 
       const data = await response.json();
       setResult(data);
-    } catch (err) {
+    } catch (_err) {
       setError('Failed to perform search. Please check your connection.');
     } finally {
       setLoading(false);
diff --git a/lib/elasticsearch.ts b/lib/elasticsearch.ts
index f0d4efb..3c0ad0c 100644
--- a/lib/elasticsearch.ts
+++ b/lib/elasticsearch.ts
@@ -16,7 +16,7 @@ export const INDEX_MAPPING = {
     analysis: {
       analyzer: {
         lowercase_analyzer: {
-          type: 'custom',
+          type: 'custom' as const,
           tokenizer: 'keyword',
           filter: ['lowercase']
         }
@@ -26,31 +26,31 @@ export const INDEX_MAPPING = {
   mappings: {
     properties: {
       plaintext: {
-        type: 'text',
+        type: 'text' as const,
         analyzer: 'lowercase_analyzer',
         fields: {
           keyword: {
-            type: 'keyword'
+            type: 'keyword' as const
           }
         }
       },
       md5: {
-        type: 'keyword'
+        type: 'keyword' as const
       },
       sha1: {
-        type: 'keyword'
+        type: 'keyword' as const
       },
       sha256: {
-        type: 'keyword'
+        type: 'keyword' as const
       },
       sha512: {
-        type: 'keyword'
+        type: 'keyword' as const
       },
       bcrypt: {
-        type: 'keyword'
+        type: 'keyword' as const
       },
       created_at: {
-        type: 'date'
+        type: 'date' as const
       }
     }
   }
@@ -63,8 +63,9 @@ export async function initializeIndex(): Promise<void> {
     if (!indexExists) {
       await esClient.indices.create({
         index: INDEX_NAME,
-        ...INDEX_MAPPING
-      } as any);
+        settings: INDEX_MAPPING.settings,
+        mappings: INDEX_MAPPING.mappings
+      });
       console.log(`Index '${INDEX_NAME}' created successfully with 10 shards`);
     } else {
       console.log(`Index '${INDEX_NAME}' already exists`);
diff --git a/lib/hash.ts b/lib/hash.ts
index 894c304..5e1d9c8 100644
--- a/lib/hash.ts
+++ b/lib/hash.ts
@@ -73,7 +73,7 @@ export function isHash(input: string): boolean {
 export async function verifyBcrypt(plaintext: string, hash: string): Promise<boolean> {
   try {
     return await bcrypt.compare(plaintext, hash);
-  } catch (error) {
+  } catch (_error) {
     return false;
   }
 }
diff --git a/package.json b/package.json
index 7c61ffc..a138ff6 100644
--- a/package.json
+++ b/package.json
@@ -41,9 +41,9 @@
     "@types/bcrypt": "^6.0.0",
     "bcrypt": "^6.0.0",
     "lucide-react": "^0.555.0",
-    "next": "16.0.7",
-    "react": "19.2.0",
-    "react-dom": "19.2.0",
+    "next": "15.4.8",
+    "react": "19.1.2",
+    "react-dom": "19.1.2",
     "tsx": "^4.21.0"
   },
   "devDependencies": {
diff --git a/tsconfig.json b/tsconfig.json
index 3a13f90..2627c60 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,7 +1,11 @@
 {
   "compilerOptions": {
     "target": "ES2017",
-    "lib": ["dom", "dom.iterable", "esnext"],
+    "lib": [
+      "dom",
+      "dom.iterable",
+      "esnext"
+    ],
     "allowJs": true,
     "skipLibCheck": true,
     "strict": true,
@@ -11,7 +15,7 @@
     "moduleResolution": "bundler",
     "resolveJsonModule": true,
     "isolatedModules": true,
-    "jsx": "react-jsx",
+    "jsx": "preserve",
     "incremental": true,
     "plugins": [
       {
@@ -19,7 +23,9 @@
       }
     ],
     "paths": {
-      "@/*": ["./*"]
+      "@/*": [
+        "./*"
+      ]
     }
   },
   "include": [
@@ -30,5 +36,7 @@
     ".next/dev/types/**/*.ts",
     "**/*.mts"
   ],
-  "exclude": ["node_modules"]
+  "exclude": [
+    "node_modules"
+  ]
 }