diff --git a/contract/contracts/hello-world/src/tests/autoshare_test.rs b/contract/contracts/hello-world/src/tests/autoshare_test.rs
index 3e577ed..f08ba4b 100644
--- a/contract/contracts/hello-world/src/tests/autoshare_test.rs
+++ b/contract/contracts/hello-world/src/tests/autoshare_test.rs
@@ -1080,6 +1080,21 @@ fn test_is_group_active_on_nonexistent_group_fails() {
     client.is_group_active(&id);
 }
 
+#[test]
+fn test_create_group_with_zero_usages_fails() {
+    let test_env = setup_test_env();
+    let client = AutoShareContractClient::new(&test_env.env, &test_env.autoshare_contract);
+
+    let creator = test_env.users.get(0).unwrap().clone();
+    let token = test_env.mock_tokens.get(0).unwrap().clone();
+    let id = BytesN::from_array(&test_env.env, &[1u8; 32]);
+    let name = String::from_str(&test_env.env, "Zero Usages");
+
+    crate::test_utils::mint_tokens(&test_env.env, &token, &creator, 10_000_000);
+    let result = client.try_create(&id, &name, &creator, &0u32, &token);
+    assert!(result.is_err(), "Creating group with 0 usages should fail");
+}
+
 #[test]
 fn test_get_all_groups_includes_inactive() {
     let test_env = setup_test_env();
diff --git a/listener/package-lock.json b/listener/package-lock.json
index 3b1d703..0389039 100644
--- a/listener/package-lock.json
+++ b/listener/package-lock.json
@@ -63,7 +63,6 @@
       "integrity": "sha512-RgHBCvtjbOK2gXSNBNIkNoEc9qoVEtau3hj8gEqKQuL3HZAibKarWFEI3Lfm6EYKkLalOh8eSrj9b+ch9H/VBA==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@babel/code-frame": "^7.29.7",
         "@babel/generator": "^7.29.7",
@@ -1409,7 +1408,6 @@
       "dev": true,
       "hasInstallScript": true,
       "license": "Apache-2.0",
-      "peer": true,
       "dependencies": {
         "@swc/counter": "^0.1.3",
         "@swc/types": "^0.1.26"
@@ -1827,7 +1825,6 @@
       "integrity": "sha512-603BddQMv3pUcr4U2dhujk83N2tTDVr/34wII2B6bJy6g+8WD6yUb11jszNs0gdi4PesVWl7ABt8nYMVpnLUcg==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "undici-types": ">=7.24.0 <7.24.7"
       }
@@ -1941,7 +1938,6 @@
       "integrity": "sha512-tbsV1jPne5CkFQCgPBcDOt30ItF7aJoZL997JSF7MhGQqOeT3svWRYxiqlfA5RUdlHN6Fi+EI9bxqbdyAUZjYQ==",
       "dev": true,
       "license": "BSD-2-Clause",
-      "peer": true,
       "dependencies": {
         "@typescript-eslint/scope-manager": "6.21.0",
         "@typescript-eslint/types": "6.21.0",
@@ -2170,7 +2166,6 @@
       "integrity": "sha512-xRQbDb9BnwDafYNn6Vwl839DYVjqXYb1XVGtWAZ1kcDc6iwAL4hg3B1dZlRiuENFeO2H53gFG3in621AdERVAg==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "bin": {
         "acorn": "bin/acorn"
       },
@@ -2683,7 +2678,6 @@
         }
       ],
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "baseline-browser-mapping": "^2.10.12",
         "caniuse-lite": "^1.0.30001782",
@@ -3492,7 +3486,6 @@
       "deprecated": "This version is no longer supported. Please see https://eslint.org/version-support for other options.",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@eslint-community/eslint-utils": "^4.2.0",
         "@eslint-community/regexpp": "^4.6.1",
@@ -4840,7 +4833,6 @@
       "integrity": "sha512-NIy3oAFp9shda19hy4HK0HRTWKtPJmGdnvywu01nOqNC2vZg+Z+fvJDxpMQA88eb2I9EcafcdjYgsDthnYTvGw==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@jest/core": "^29.7.0",
         "@jest/types": "^29.6.3",
@@ -7401,7 +7393,6 @@
       "integrity": "sha512-f0FFpIdcHgn8zcPSbf1dRevwt047YMnaiJM3u2w2RewrB+fob/zePZcrOyQoLMMO7aBIddLcQIEK5dYjkLnGrQ==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@cspotcode/source-map-support": "^0.8.0",
         "@tsconfig/node10": "^1.0.7",
@@ -7508,7 +7499,6 @@
       "integrity": "sha512-y2TvuxSZPDyQakkFRPZHKFm+KKVqIisdg9/CZwm9ftvKXLP8NRWj38/ODjNbr43SsoXqNuAisEf1GdCxqWcdBw==",
       "dev": true,
       "license": "Apache-2.0",
-      "peer": true,
       "bin": {
         "tsc": "bin/tsc",
         "tsserver": "bin/tsserver"
diff --git a/listener/src/index.ts b/listener/src/index.ts
index 97bbce1..5feb94c 100644
--- a/listener/src/index.ts
+++ b/listener/src/index.ts
@@ -50,6 +50,9 @@ async function main() {
     logger.info('Initializing database');
     const db = await initializeDatabase(config.databasePath);
 
+    // Initialize deduplication service
+    deduplicationService = new EventDeduplicationService(db);
+
     // Rebuild registry with configured event TTL
     if (config.cleanup) {
       (eventRegistry as any).ttlMs = config.cleanup.eventRetentionMs;