diff --git a/packages/experiment-tag/src/experiment.ts b/packages/experiment-tag/src/experiment.ts
index ff745042..88836c48 100644
--- a/packages/experiment-tag/src/experiment.ts
+++ b/packages/experiment-tag/src/experiment.ts
@@ -1,4 +1,5 @@
-import { Experiment } from '@amplitude/experiment-js-client';
+import { EvaluationFlag } from '@amplitude/experiment-core';
+import { Experiment, ExperimentUser } from '@amplitude/experiment-js-client';
 
 import {
   getGlobalScope,
@@ -13,11 +14,11 @@ export const initializeExperiment = (apiKey: string, initialFlags: string) => {
   const globalScope = getGlobalScope();
   const experimentStorageName = `EXP_${apiKey.slice(0, 10)}`;
 
-  if (isLocalStorageAvailable()) {
-    let user = undefined;
+  if (isLocalStorageAvailable() && globalScope) {
+    let user: ExperimentUser;
     try {
       user = JSON.parse(
-        globalScope.localStorage.getItem(experimentStorageName) || '{}',
+        globalScope?.localStorage.getItem(experimentStorageName) || '{}',
       );
     } catch (error) {
       user = {};
@@ -27,7 +28,7 @@ export const initializeExperiment = (apiKey: string, initialFlags: string) => {
     if (Object.keys(user).length === 0 || !user.device_id) {
       user = {};
       user.device_id = UUID();
-      globalScope.localStorage.setItem(
+      globalScope?.localStorage.setItem(
         experimentStorageName,
         JSON.stringify(user),
       );
@@ -36,7 +37,7 @@ export const initializeExperiment = (apiKey: string, initialFlags: string) => {
     const urlParams = getUrlParams();
     const parsedFlags = JSON.parse(initialFlags);
 
-    parsedFlags.forEach((flag) => {
+    parsedFlags.forEach((flag: EvaluationFlag) => {
       if (flag.key in urlParams && urlParams[flag.key] in flag.variants) {
         flag.segments = [
           {
diff --git a/packages/experiment-tag/src/util.ts b/packages/experiment-tag/src/util.ts
index dc65316d..ef13e9e4 100644
--- a/packages/experiment-tag/src/util.ts
+++ b/packages/experiment-tag/src/util.ts
@@ -17,7 +17,7 @@ export const getGlobalScope = (): typeof globalThis | undefined => {
 // Get URL parameters
 export const getUrlParams = (): Record<string, string> => {
   const globalScope = getGlobalScope();
-  const searchParams = new URLSearchParams(globalScope.location.search);
+  const searchParams = new URLSearchParams(globalScope?.location.search);
   const params: Record<string, string> = {};
   for (const [key, value] of searchParams) {
     params[key] = value;
@@ -50,7 +50,7 @@ export const UUID = function (a?: number): string {
         .replace(
           // replacing
           /[018]/g, // zeroes, ones, and eights with
-          UUID, // random hex digits
+          UUID(), // random hex digits
         );
 };
 
@@ -64,12 +64,16 @@ export const matchesUrl = (urlArray: string[], urlString: string): boolean => {
 };
 
 export const isLocalStorageAvailable = (): boolean => {
-  try {
-    const testKey = 'EXP_test';
-    localStorage.setItem(testKey, testKey);
-    localStorage.removeItem(testKey);
-    return true;
-  } catch (e) {
-    return false;
+  const globalScope = getGlobalScope();
+  if (globalScope) {
+    try {
+      const testKey = 'EXP_test';
+      globalScope.localStorage.setItem(testKey, testKey);
+      globalScope.localStorage.removeItem(testKey);
+      return true;
+    } catch (e) {
+      return false;
+    }
   }
+  return false;
 };
diff --git a/packages/experiment-tag/tsconfig.json b/packages/experiment-tag/tsconfig.json
index ac4bc597..ece1f0c8 100644
--- a/packages/experiment-tag/tsconfig.json
+++ b/packages/experiment-tag/tsconfig.json
@@ -2,6 +2,7 @@
   "extends": "../../tsconfig.json",
   "include": ["src/**/*.ts", "package.json"],
   "compilerOptions": {
+    "noImplicitAny": false,
     "declaration": true,
     "declarationDir": "dist/types",
     "downlevelIteration": true,
diff --git a/yarn.lock b/yarn.lock
index d24a6c27..507e8a06 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1389,22 +1389,49 @@
     "@jridgewell/sourcemap-codec" "^1.4.10"
     "@jridgewell/trace-mapping" "^0.3.9"
 
+"@jridgewell/gen-mapping@^0.3.5":
+  version "0.3.5"
+  resolved "https://registry.yarnpkg.com/@jridgewell/gen-mapping/-/gen-mapping-0.3.5.tgz#dcce6aff74bdf6dad1a95802b69b04a2fcb1fb36"
+  integrity sha512-IzL8ZoEDIBRWEzlCcRhOaCupYyN5gdIK+Q6fbFdPDg6HqX6jpkItn7DFIpW9LQzXG6Df9sA7+OKnq0qlz/GaQg==
+  dependencies:
+    "@jridgewell/set-array" "^1.2.1"
+    "@jridgewell/sourcemap-codec" "^1.4.10"
+    "@jridgewell/trace-mapping" "^0.3.24"
+
 "@jridgewell/resolve-uri@3.1.0":
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/@jridgewell/resolve-uri/-/resolve-uri-3.1.0.tgz#2203b118c157721addfe69d47b70465463066d78"
   integrity sha512-F2msla3tad+Mfht5cJq7LSXcdudKTWCVYUgw6pLFOOHSTtZlj6SWNYAp+AhuqLmWdBO2X5hPrLcu8cVP8fy28w==
 
+"@jridgewell/resolve-uri@^3.1.0":
+  version "3.1.2"
+  resolved "https://registry.yarnpkg.com/@jridgewell/resolve-uri/-/resolve-uri-3.1.2.tgz#7a0ee601f60f99a20c7c7c5ff0c80388c1189bd6"
+  integrity sha512-bRISgCIjP20/tbWSPWMEi54QVPRZExkuD9lJL+UIxUKtwVJA8wW1Trb1jMs1RFXo1CBTNZ/5hpC9QvmKWdopKw==
+
 "@jridgewell/set-array@^1.0.1":
   version "1.1.2"
   resolved "https://registry.yarnpkg.com/@jridgewell/set-array/-/set-array-1.1.2.tgz#7c6cf998d6d20b914c0a55a91ae928ff25965e72"
   integrity sha512-xnkseuNADM0gt2bs+BvhO0p78Mk762YnZdsuzFV018NoG1Sj1SCQvpSqa7XUaTam5vAGasABV9qXASMKnFMwMw==
 
+"@jridgewell/set-array@^1.2.1":
+  version "1.2.1"
+  resolved "https://registry.yarnpkg.com/@jridgewell/set-array/-/set-array-1.2.1.tgz#558fb6472ed16a4c850b889530e6b36438c49280"
+  integrity sha512-R8gLRTZeyp03ymzP/6Lil/28tGeGEzhx1q2k703KGWRAI1VdvPIXdG70VJc2pAMw3NA6JKL5hhFu1sJX0Mnn/A==
+
+"@jridgewell/source-map@^0.3.3":
+  version "0.3.6"
+  resolved "https://registry.yarnpkg.com/@jridgewell/source-map/-/source-map-0.3.6.tgz#9d71ca886e32502eb9362c9a74a46787c36df81a"
+  integrity sha512-1ZJTZebgqllO79ue2bm3rIGud/bOe0pP5BjSRCRxxYkEZS8STV7zN84UBbiYu7jy+eCKSnVIUgoWWE/tt+shMQ==
+  dependencies:
+    "@jridgewell/gen-mapping" "^0.3.5"
+    "@jridgewell/trace-mapping" "^0.3.25"
+
 "@jridgewell/sourcemap-codec@1.4.14":
   version "1.4.14"
   resolved "https://registry.yarnpkg.com/@jridgewell/sourcemap-codec/-/sourcemap-codec-1.4.14.tgz#add4c98d341472a289190b424efbdb096991bb24"
   integrity sha512-XPSJHWmi394fuUuzDnGz1wiKqWfo1yXecHQMRf2l6hztTO+nPru658AyDngaBe7isIxEkRsPR3FZh+s7iVa4Uw==
 
-"@jridgewell/sourcemap-codec@^1.4.10":
+"@jridgewell/sourcemap-codec@^1.4.10", "@jridgewell/sourcemap-codec@^1.4.14":
   version "1.4.15"
   resolved "https://registry.yarnpkg.com/@jridgewell/sourcemap-codec/-/sourcemap-codec-1.4.15.tgz#d7c6e6755c78567a951e04ab52ef0fd26de59f32"
   integrity sha512-eF2rxCRulEKXHTRiDrDy6erMYWqNw4LPdQ8UQA4huuxaQsVeRPFl2oM8oDGxMFhJUWZf9McpLtJasDDZb/Bpeg==
@@ -1417,6 +1444,14 @@
     "@jridgewell/resolve-uri" "3.1.0"
     "@jridgewell/sourcemap-codec" "1.4.14"
 
+"@jridgewell/trace-mapping@^0.3.24", "@jridgewell/trace-mapping@^0.3.25":
+  version "0.3.25"
+  resolved "https://registry.yarnpkg.com/@jridgewell/trace-mapping/-/trace-mapping-0.3.25.tgz#15f190e98895f3fc23276ee14bc76b675c2e50f0"
+  integrity sha512-vNk6aEwybGtawWmy/PzwnGDOjCkLWSD2wqvjGGAgOAwCGWySYXfYoxt00IJkTF+8Lb57DwOb3Aa0o9CApepiYQ==
+  dependencies:
+    "@jridgewell/resolve-uri" "^3.1.0"
+    "@jridgewell/sourcemap-codec" "^1.4.14"
+
 "@lerna/child-process@6.6.2":
   version "6.6.2"
   resolved "https://registry.yarnpkg.com/@lerna/child-process/-/child-process-6.6.2.tgz#5d803c8dee81a4e013dc428292e77b365cba876c"
@@ -1967,6 +2002,15 @@
     "@rollup/pluginutils" "^3.1.0"
     magic-string "^0.25.7"
 
+"@rollup/plugin-terser@^0.4.4":
+  version "0.4.4"
+  resolved "https://registry.yarnpkg.com/@rollup/plugin-terser/-/plugin-terser-0.4.4.tgz#15dffdb3f73f121aa4fbb37e7ca6be9aeea91962"
+  integrity sha512-XHeJC5Bgvs8LfukDwWZp7yeqin6ns8RTl2B9avbejt6tZqsqvVoWI7ZTQrcNsfKEDWBTnTxM8nMDkO2IFFbd0A==
+  dependencies:
+    serialize-javascript "^6.0.1"
+    smob "^1.0.0"
+    terser "^5.17.4"
+
 "@rollup/plugin-typescript@^11.1.0":
   version "11.1.2"
   resolved "https://registry.yarnpkg.com/@rollup/plugin-typescript/-/plugin-typescript-11.1.2.tgz#09eb5690a650bb0334bf84125bce9abd296442e4"
@@ -2403,6 +2447,11 @@ acorn@^8.1.0, acorn@^8.8.1:
   resolved "https://registry.yarnpkg.com/acorn/-/acorn-8.10.0.tgz#8be5b3907a67221a81ab23c7889c4c5526b62ec5"
   integrity sha512-F0SAmZ8iUtS//m8DmCTA0jlh6TDKkHQyK6xc6V4KDTyZKA9dnvX9/3sRTVQrWm79glUAZbnmmNcdYwUIHWVybw==
 
+acorn@^8.8.2:
+  version "8.11.3"
+  resolved "https://registry.yarnpkg.com/acorn/-/acorn-8.11.3.tgz#71e0b14e13a4ec160724b38fb7b0f233b1b81d7a"
+  integrity sha512-Y9rRfJG5jcKOE0CLisYbojUjIrIEE7AGMzA/Sm4BslANhbS+cDMpgBdcPT91oJ7OuJ9hYJBx59RjbhxVnrF8Xg==
+
 add-stream@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/add-stream/-/add-stream-1.0.0.tgz#6a7990437ca736d5e1288db92bd3266d5f5cb2aa"
@@ -3145,6 +3194,11 @@ combined-stream@^1.0.8:
   dependencies:
     delayed-stream "~1.0.0"
 
+commander@^2.20.0:
+  version "2.20.3"
+  resolved "https://registry.yarnpkg.com/commander/-/commander-2.20.3.tgz#fd485e84c03eb4881c20722ba48035e8531aeb33"
+  integrity sha512-GpVkmM8vF2vQUkj2LvZmD35JxeJOLCwJ9cUkugyk2nuhbv3+mJvpLYYt+0+USMxE+oj+ey/lJEnhZw75x/OMcQ==
+
 common-ancestor-path@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/common-ancestor-path/-/common-ancestor-path-1.0.1.tgz#4f7d2d1394d91b7abdf51871c62f71eadb0182a7"
@@ -7177,6 +7231,13 @@ quick-lru@^4.0.1:
   resolved "https://registry.yarnpkg.com/quick-lru/-/quick-lru-4.0.1.tgz#5b8878f113a58217848c6482026c73e1ba57727f"
   integrity sha512-ARhCpm70fzdcvNQfPoy49IaanKkTlRWF2JMzqhcJbhSFRZv7nPTvZJdcY7301IPmvW+/p0RgIWnQDLJxifsQ7g==
 
+randombytes@^2.1.0:
+  version "2.1.0"
+  resolved "https://registry.yarnpkg.com/randombytes/-/randombytes-2.1.0.tgz#df6f84372f0270dc65cdf6291349ab7a473d4f2a"
+  integrity sha512-vYl3iOX+4CKUWuxGi9Ukhie6fsqXqS9FE2Zaic4tNFD2N2QQaXOMFbuKK4QmDHC0JO6B1Zp41J0LpT0oR68amQ==
+  dependencies:
+    safe-buffer "^5.1.0"
+
 react-is@^17.0.1:
   version "17.0.2"
   resolved "https://registry.yarnpkg.com/react-is/-/react-is-17.0.2.tgz#e691d4a8e9c789365655539ab372762b0efb54f0"
@@ -7508,16 +7569,16 @@ safe-array-concat@^1.0.0:
     has-symbols "^1.0.3"
     isarray "^2.0.5"
 
+safe-buffer@^5.1.0, safe-buffer@~5.2.0:
+  version "5.2.1"
+  resolved "https://registry.yarnpkg.com/safe-buffer/-/safe-buffer-5.2.1.tgz#1eaf9fa9bdb1fdd4ec75f58f9cdb4e6b7827eec6"
+  integrity sha512-rp3So07KcdmmKbGvgaNxQSJr7bGVSVk5S9Eq1F+ppbRo70+YeaDxkw5Dd8NPN+GD6bjnYm2VuPuCXmpuYvmCXQ==
+
 safe-buffer@~5.1.0, safe-buffer@~5.1.1:
   version "5.1.2"
   resolved "https://registry.yarnpkg.com/safe-buffer/-/safe-buffer-5.1.2.tgz#991ec69d296e0313747d59bdfd2b745c35f8828d"
   integrity sha512-Gd2UZBJDkXlY7GbJxfsE8/nvKkUEU1G38c1siN6QP6a9PT9MmHB8GnpscSmMJSoF8LOIrt8ud/wPtojys4G6+g==
 
-safe-buffer@~5.2.0:
-  version "5.2.1"
-  resolved "https://registry.yarnpkg.com/safe-buffer/-/safe-buffer-5.2.1.tgz#1eaf9fa9bdb1fdd4ec75f58f9cdb4e6b7827eec6"
-  integrity sha512-rp3So07KcdmmKbGvgaNxQSJr7bGVSVk5S9Eq1F+ppbRo70+YeaDxkw5Dd8NPN+GD6bjnYm2VuPuCXmpuYvmCXQ==
-
 safe-regex-test@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/safe-regex-test/-/safe-regex-test-1.0.0.tgz#793b874d524eb3640d1873aad03596db2d4f2295"
@@ -7570,6 +7631,13 @@ semver@^7.0.0, semver@^7.1.1, semver@^7.2.1, semver@^7.3.4, semver@^7.3.5, semve
   dependencies:
     lru-cache "^6.0.0"
 
+serialize-javascript@^6.0.1:
+  version "6.0.2"
+  resolved "https://registry.yarnpkg.com/serialize-javascript/-/serialize-javascript-6.0.2.tgz#defa1e055c83bf6d59ea805d8da862254eb6a6c2"
+  integrity sha512-Saa1xPByTTq2gdeFZYLLo+RFE35NHZkAbqZeWNd3BpzppeVisAqpDjcp8dyf6uIvEqJRd46jemmyA4iFIeVk8g==
+  dependencies:
+    randombytes "^2.1.0"
+
 set-blocking@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/set-blocking/-/set-blocking-2.0.0.tgz#045f9782d011ae9a6803ddd382b24392b3d890f7"
@@ -7657,6 +7725,11 @@ smart-buffer@^4.2.0:
   resolved "https://registry.yarnpkg.com/smart-buffer/-/smart-buffer-4.2.0.tgz#6e1d71fa4f18c05f7d0ff216dd16a481d0e8d9ae"
   integrity sha512-94hK0Hh8rPqQl2xXc3HsaBoOXKV20MToPkcXvwbISWLEs+64sBq5kFgn2kJDHb1Pry9yrP0dxrCI9RRci7RXKg==
 
+smob@^1.0.0:
+  version "1.5.0"
+  resolved "https://registry.yarnpkg.com/smob/-/smob-1.5.0.tgz#85d79a1403abf128d24d3ebc1cdc5e1a9548d3ab"
+  integrity sha512-g6T+p7QO8npa+/hNx9ohv1E5pVCmWrVCUzUXJyLdMmftX6ER0oiWY/w9knEonLpnOp6b6FenKnMfR8gqwWdwig==
+
 socks-proxy-agent@^7.0.0:
   version "7.0.0"
   resolved "https://registry.yarnpkg.com/socks-proxy-agent/-/socks-proxy-agent-7.0.0.tgz#dc069ecf34436621acb41e3efa66ca1b5fed15b6"
@@ -7689,6 +7762,14 @@ source-map-support@0.5.13:
     buffer-from "^1.0.0"
     source-map "^0.6.0"
 
+source-map-support@~0.5.20:
+  version "0.5.21"
+  resolved "https://registry.yarnpkg.com/source-map-support/-/source-map-support-0.5.21.tgz#04fe7c7f9e1ed2d662233c28cb2b35b9f63f6e4f"
+  integrity sha512-uBHU3L3czsIyYXKX88fdrGovxdSCoTGDRZ6SYXtSRxLZUzHg5P/66Ht6uoUlHu9EZod+inXhKo3qQgwXUT/y1w==
+  dependencies:
+    buffer-from "^1.0.0"
+    source-map "^0.6.0"
+
 source-map@^0.6.0, source-map@^0.6.1, source-map@~0.6.1:
   version "0.6.1"
   resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.6.1.tgz#74722af32e9614e9c287a8d0bbde48b5e2f1a263"
@@ -7985,6 +8066,16 @@ tempy@1.0.0:
     type-fest "^0.16.0"
     unique-string "^2.0.0"
 
+terser@^5.17.4:
+  version "5.30.3"
+  resolved "https://registry.yarnpkg.com/terser/-/terser-5.30.3.tgz#f1bb68ded42408c316b548e3ec2526d7dd03f4d2"
+  integrity sha512-STdUgOUx8rLbMGO9IOwHLpCqolkDITFFQSMYYwKE1N2lY6MVSaeoi10z/EhWxRc6ybqoVmKSkhKYH/XUpl7vSA==
+  dependencies:
+    "@jridgewell/source-map" "^0.3.3"
+    acorn "^8.8.2"
+    commander "^2.20.0"
+    source-map-support "~0.5.20"
+
 test-exclude@^6.0.0:
   version "6.0.0"
   resolved "https://registry.yarnpkg.com/test-exclude/-/test-exclude-6.0.0.tgz#04a8698661d805ea6fa293b6cb9e63ac044ef15e"