diff --git a/src/appdistribution/distribution.spec.ts b/src/appdistribution/distribution.spec.ts
index a8f73f63b16..9b898737b9d 100644
--- a/src/appdistribution/distribution.spec.ts
+++ b/src/appdistribution/distribution.spec.ts
@@ -68,7 +68,16 @@ describe("appdistribution/distribution", () => {
       mockClient.uploadRelease.resolves("operations/123");
       mockClient.pollUploadStatus.resolves({
         result: UploadReleaseResult.RELEASE_CREATED,
-        release: { displayVersion: "1.0", buildVersion: "1", name: "test-rel" } as unknown as any,
+        release: {
+          displayVersion: "1.0",
+          buildVersion: "1",
+          name: "test-rel",
+          releaseNotes: { text: "test-notes" },
+          createTime: new Date(),
+          firebaseConsoleUri: "http://console.firebase.google.com",
+          testingUri: "http://testing.firebase.google.com",
+          binaryDownloadUri: "http://download.firebase.google.com",
+        },
       });
 
       const res = await upload(
@@ -94,11 +103,16 @@ describe("appdistribution/distribution", () => {
 
   describe("awaitTestResults", () => {
     it("should succeed when all tests pass on first poll", async () => {
-      const releaseTests: ReleaseTest[] = [{ name: "tests/1", deviceExecutions: [] } as any];
+      const releaseTests: ReleaseTest[] = [{ name: "tests/1", deviceExecutions: [] }];
       mockClient.getReleaseTest.resolves({
         name: "tests/1",
-        deviceExecutions: [{ state: "PASSED", device: { model: "Pixel" } as unknown as any }],
-      } as unknown as ReleaseTest);
+        deviceExecutions: [
+          {
+            state: "PASSED",
+            device: { model: "Pixel", version: "14", locale: "en_US", orientation: "PORTRAIT" },
+          },
+        ],
+      });
 
       const setTimeoutStub = sinon.stub(global, "setTimeout").callsFake((fn) => fn() as any);
 
@@ -109,11 +123,15 @@ describe("appdistribution/distribution", () => {
     });
 
     it("should fail immediately when a test execution fails", async () => {
-      const releaseTests: ReleaseTest[] = [{ name: "tests/1", deviceExecutions: [] } as any];
+      const releaseTests: ReleaseTest[] = [{ name: "tests/1", deviceExecutions: [] }];
       mockClient.getReleaseTest.resolves({
         name: "tests/1",
         deviceExecutions: [
-          { state: "FAILED", failedReason: "Crash", device: { model: "Pixel" } as any },
+          {
+            state: "FAILED",
+            failedReason: "Crash",
+            device: { model: "Pixel", version: "14", locale: "en_US", orientation: "PORTRAIT" },
+          },
         ],
       } as any);
 
diff --git a/src/apphosting/secrets/index.ts b/src/apphosting/secrets/index.ts
index b9c8f64d8af..c85f0645abc 100644
--- a/src/apphosting/secrets/index.ts
+++ b/src/apphosting/secrets/index.ts
@@ -282,13 +282,21 @@ export async function loadSecret(project: string | undefined, name: string): Pro
   }
   try {
     return await gcsm.accessSecretVersion(projectId, secretId, version);
-  } catch (err: any) {
-    if (err?.original?.code === 403 || err?.original?.context?.response?.statusCode === 403) {
-      utils.logLabeledError(
-        "apphosting",
-        `Permission denied to access secret ${secretId}. Use ` +
-          `${clc.bold("firebase apphosting:secrets:grantaccess")} to get permissions.`,
-      );
+  } catch (err: unknown) {
+    if (err instanceof FirebaseError) {
+      const original = err.original;
+      if (typeof original === "object" && original !== null) {
+        if (
+          (original as any).code === 403 ||
+          (original as any).context?.response?.statusCode === 403
+        ) {
+          utils.logLabeledError(
+            "apphosting",
+            `Permission denied to access secret ${secretId}. Use ` +
+              `${clc.bold("firebase apphosting:secrets:grantaccess")} to get permissions.`,
+          );
+        }
+      }
     }
     throw err;
   }
diff --git a/src/emulator/adminSdkConfig.ts b/src/emulator/adminSdkConfig.ts
index e85c7dcac57..96d4a194e05 100644
--- a/src/emulator/adminSdkConfig.ts
+++ b/src/emulator/adminSdkConfig.ts
@@ -2,6 +2,7 @@ import { firebaseApiOrigin } from "../api";
 import * as apiv2 from "../apiv2";
 import { configstore } from "../configstore";
 import { FirebaseError } from "../error";
+import { getError } from "../error";
 import { logger } from "../logger";
 import { Constants } from "./constants";
 
@@ -43,7 +44,7 @@ export async function getProjectAdminSdkConfigOrCached(
     const config = await getProjectAdminSdkConfig(projectId);
     setCacheAdminSdkConfig(projectId, config);
     return config;
-  } catch (e: any) {
+  } catch (e: unknown) {
     logger.debug(`Failed to get Admin SDK config for ${projectId}, falling back to cache`, e);
     return getCachedAdminSdkConfig(projectId);
   }
@@ -71,11 +72,11 @@ async function getProjectAdminSdkConfig(projectId: string): Promise<AdminSdkConf
   try {
     const res = await apiClient.get<AdminSdkConfig>(`projects/${projectId}/adminSdkConfig`);
     return res.body;
-  } catch (err: any) {
+  } catch (err: unknown) {
     throw new FirebaseError(
       `Failed to get Admin SDK for Firebase project ${projectId}. ` +
         "Please make sure the project exists and your account has permission to access it.",
-      { exit: 2, original: err },
+      { exit: 2, original: getError(err) },
     );
   }
 }
diff --git a/src/emulator/auth/operations.ts b/src/emulator/auth/operations.ts
index 22f8e0c1847..bb77fbf8312 100644
--- a/src/emulator/auth/operations.ts
+++ b/src/emulator/auth/operations.ts
@@ -1642,7 +1642,7 @@ async function signInWithIdp(
         userMatchingProvider,
       ));
     }
-  } catch (err: any) {
+  } catch (err: unknown) {
     if (reqBody.returnIdpCredential && err instanceof BadRequestError) {
       response.errorMessage = err.message;
       return response;
diff --git a/src/emulator/commandUtils.ts b/src/emulator/commandUtils.ts
index 843ae373d5e..4306ca0fa69 100644
--- a/src/emulator/commandUtils.ts
+++ b/src/emulator/commandUtils.ts
@@ -11,6 +11,7 @@ import { requireAuth } from "../requireAuth";
 import { requireConfig } from "../requireConfig";
 import { Emulators, ALL_SERVICE_EMULATORS } from "./types";
 import { FirebaseError } from "../error";
+import { getError } from "../error";
 import { EmulatorRegistry } from "./registry";
 import { getProjectId } from "../projectUtils";
 import { confirm } from "../prompt";
@@ -172,8 +173,8 @@ export async function beforeEmulatorCommand(options: any): Promise<any> {
   ) {
     try {
       await requireAuth(options);
-    } catch (e: any) {
-      logger.debug(e);
+    } catch (e: unknown) {
+      logger.debug(e as any);
       utils.logLabeledWarning(
         "emulators",
         `You are not currently authenticated so some features may not work correctly. Please run ${clc.bold(
@@ -333,8 +334,8 @@ function processKillSignal(
         }
       }
       res();
-    } catch (e: any) {
-      logger.debug(e);
+    } catch (e: unknown) {
+      logger.debug(e as any);
       rej();
     }
   };
@@ -512,9 +513,11 @@ export async function checkJavaMajorVersion(): Promise<number> {
           stdio: ["inherit", "pipe", "pipe"],
         },
       );
-    } catch (err: any) {
+    } catch (err: unknown) {
       return reject(
-        new FirebaseError(`Could not spawn \`java -version\`. ${JAVA_HINT}`, { original: err }),
+        new FirebaseError(`Could not spawn \`java -version\`. ${JAVA_HINT}`, {
+          original: getError(err),
+        }),
       );
     }
 
diff --git a/src/emulator/controller.ts b/src/emulator/controller.ts
index d02aac363c0..493dc0834db 100755
--- a/src/emulator/controller.ts
+++ b/src/emulator/controller.ts
@@ -20,6 +20,7 @@ import {
 import { Constants, FIND_AVAILBLE_PORT_BY_DEFAULT } from "./constants";
 import { EmulatableBackend, FunctionsEmulator } from "./functionsEmulator";
 import { FirebaseError } from "../error";
+import { getErrMsg, getError } from "../error";
 import { getProjectId, getAliases, needProjectNumber } from "../projectUtils";
 import * as commandUtils from "./commandUtils";
 import { EmulatorHub } from "./hub";
@@ -174,11 +175,11 @@ export function shouldStart(options: Options, name: Emulators): boolean {
     try {
       normalizeAndValidate(options.config.src.functions);
       return true;
-    } catch (err: any) {
+    } catch (err: unknown) {
       EmulatorLogger.forEmulator(Emulators.FUNCTIONS).logLabeled(
         "ERROR",
         "functions",
-        `Failed to start Functions emulator: ${err.message}`,
+        `Failed to start Functions emulator: ${getErrMsg(err)}`,
       );
       return false;
     }
@@ -357,7 +358,7 @@ export async function startAll(
     if (!isDemoProject) {
       try {
         projectNumber = await needProjectNumber(options);
-      } catch (err: any) {
+      } catch (err: unknown) {
         EmulatorLogger.forEmulator(Emulators.EXTENSIONS).logLabeled(
           "ERROR",
           Emulators.EXTENSIONS,
@@ -781,11 +782,8 @@ export async function startAll(
       if (!options.instance) {
         options.instance = await getDefaultDatabaseInstance(projectId);
       }
-    } catch (e: any) {
-      databaseLogger.log(
-        "DEBUG",
-        `Failed to retrieve default database instance: ${JSON.stringify(e)}`,
-      );
+    } catch (e: unknown) {
+      databaseLogger.log("DEBUG", `Failed to retrieve default database instance: ${getErrMsg(e)}`);
     }
 
     const rc = dbRulesConfig.normalizeRulesConfig(
@@ -1117,7 +1115,7 @@ export async function exportEmulatorData(exportPath: string, options: any, initi
   let origin;
   try {
     origin = await hubClient.getStatus();
-  } catch (e: any) {
+  } catch (e: unknown) {
     const filePath = EmulatorHub.getLocatorFilePath(projectId);
     throw new FirebaseError(
       `The emulator hub for ${projectId} did not respond to a status check. If this error continues try shutting down all running emulators and deleting the file ${filePath}`,
@@ -1161,10 +1159,10 @@ export async function exportEmulatorData(exportPath: string, options: any, initi
   try {
     const targets = filterEmulatorTargets(options);
     await hubClient.postExport({ path: exportAbsPath, initiatedBy, targets });
-  } catch (e: any) {
+  } catch (e: unknown) {
     throw new FirebaseError("Export request failed, see emulator logs for more information.", {
       exit: 1,
-      original: e,
+      original: getError(e),
     });
   }
 
diff --git a/src/emulator/dataconnectEmulator.ts b/src/emulator/dataconnectEmulator.ts
index 3283e4aa8bf..a0f129604ea 100644
--- a/src/emulator/dataconnectEmulator.ts
+++ b/src/emulator/dataconnectEmulator.ts
@@ -16,6 +16,7 @@ import {
 } from "./downloadableEmulators";
 import { EmulatorInfo, EmulatorInstance, Emulators, ListenSpec } from "./types";
 import { FirebaseError } from "../error";
+import { getErrMsg, getErrStatus } from "../error";
 import { EmulatorLogger } from "./emulatorLogger";
 import { BuildResult, mainSchemaYaml, requiresVector } from "../dataconnect/types";
 import { listenSpecsToString } from "./portUtils";
@@ -95,8 +96,8 @@ export class DataConnectEmulator implements EmulatorInstance {
           );
         }
       }
-    } catch (err: any) {
-      this.logger.log("DEBUG", `'fdc build' failed with error: ${err.message}`);
+    } catch (err: unknown) {
+      this.logger.log("DEBUG", `'fdc build' failed with error: ${getErrMsg(err)}`);
     }
     const env = await DataConnectEmulator.getEnv(this.args.account, this.args.extraEnv);
     await start(
@@ -259,8 +260,8 @@ export class DataConnectEmulator implements EmulatorInstance {
           // Handle errors like command not found
           reject(err);
         });
-      } catch (e: any) {
-        if (isIncomaptibleArchError(e)) {
+      } catch (e: unknown) {
+        if (isIncomaptibleArchError(e as Error)) {
           reject(
             new FirebaseError(
               `Unknown system error when running the SQL Connect toolkit. ` +
@@ -343,14 +344,14 @@ export class DataConnectEmulator implements EmulatorInstance {
           `Successfully connected to ${connectionString}}`,
         );
         return true;
-      } catch (err: any) {
+      } catch (err: unknown) {
         if (i === MAX_RETRIES) {
           throw err;
         }
         this.logger.logLabeled(
           "DEBUG",
           "SQL Connect",
-          `Retrying connectToPostgress call (${i} of ${MAX_RETRIES} attempts): ${err}`,
+          `Retrying connectToPostgress call (${i} of ${MAX_RETRIES} attempts): ${getErrMsg(err)}`,
         );
         await new Promise((resolve) => setTimeout(resolve, 2000));
       }
@@ -413,9 +414,11 @@ export class DataConnectEmulatorClient {
         body,
       );
       return res;
-    } catch (err: any) {
-      if (err.status === 500) {
-        throw new FirebaseError(`SQL Connect emulator: ${err?.context?.body?.message}`);
+    } catch (err: unknown) {
+      const status = getErrStatus(err);
+      if (status === 500) {
+        const message = (err as any)?.context?.body?.message;
+        throw new FirebaseError(`SQL Connect emulator: ${message || String(err)}`);
       }
       throw err;
     }
diff --git a/src/emulator/download.ts b/src/emulator/download.ts
index 062f827a930..b26b38ec9eb 100644
--- a/src/emulator/download.ts
+++ b/src/emulator/download.ts
@@ -40,7 +40,7 @@ export async function downloadEmulator(name: DownloadableEmulators): Promise<voi
   let tmpfile: string;
   try {
     tmpfile = await downloadUtils.downloadToTmp(emulator.opts.remoteUrl, !!emulator.opts.auth);
-  } catch (err: any) {
+  } catch (err: unknown) {
     if (overrideVersion && err instanceof FirebaseError && err.status === 404) {
       throw new FirebaseError(
         `env variable ${name.toUpperCase()}_EMULATOR_VERSION set to ${overrideVersion}, 
diff --git a/src/emulator/functionsEmulator.ts b/src/emulator/functionsEmulator.ts
index 23fe6167a64..a4fa725986a 100644
--- a/src/emulator/functionsEmulator.ts
+++ b/src/emulator/functionsEmulator.ts
@@ -866,10 +866,11 @@ export class FunctionsEmulator implements EmulatorInstance {
         );
         try {
           await this.startRuntime(emulatableBackend);
-        } catch (e: any) {
+        } catch (e: unknown) {
+          const message = e instanceof Error ? e.message : String(e);
           this.logger.logLabeled(
             "ERROR",
-            `Failed to start functions in ${emulatableBackend.functionsDir}: ${e}`,
+            `Failed to start functions in ${emulatableBackend.functionsDir}: ${message}`,
           );
         }
       }
@@ -1172,8 +1173,8 @@ export class FunctionsEmulator implements EmulatorInstance {
     const client = EmulatorRegistry.client(Emulators.DATABASE);
     try {
       await client.post(apiPath, bundle, { headers: { Authorization: "Bearer owner" } });
-    } catch (err: any) {
-      this.logger.log("WARN", "Error adding Realtime Database function: " + err);
+    } catch (err: unknown) {
+      this.logger.log("WARN", "Error adding Realtime Database function: " + String(err));
       throw err;
     }
     return true;
@@ -1246,8 +1247,8 @@ export class FunctionsEmulator implements EmulatorInstance {
     const client = EmulatorRegistry.client(Emulators.FIRESTORE);
     try {
       signature === "cloudevent" ? await client.post(path, bundle) : await client.put(path, bundle);
-    } catch (err: any) {
-      this.logger.log("WARN", "Error adding firestore function: " + err);
+    } catch (err: unknown) {
+      this.logger.log("WARN", "Error adding firestore function: " + String(err));
       throw err;
     }
     return true;
@@ -1480,7 +1481,7 @@ export class FunctionsEmulator implements EmulatorInstance {
     if (functionsEnv.hasUserEnvs(projectInfo)) {
       try {
         return functionsEnv.loadUserEnvs(projectInfo);
-      } catch (e: any) {
+      } catch (e: unknown) {
         // Ignore - user envs are optional.
         logger.debug("Failed to load local environment variables", e);
       }
@@ -1578,13 +1579,17 @@ export class FunctionsEmulator implements EmulatorInstance {
     try {
       const data = fs.readFileSync(secretPath, "utf8");
       secretEnvs = functionsEnv.parseStrict(data);
-    } catch (e: any) {
-      if (e.code !== "ENOENT") {
-        this.logger.logLabeled(
-          "ERROR",
-          "functions",
-          `Failed to read local secrets file ${secretPath}: ${e.message}`,
-        );
+    } catch (e: unknown) {
+      if (typeof e === "object" && e !== null && "code" in e) {
+        const code = (e as { code: unknown }).code;
+        if (code !== "ENOENT") {
+          const message = e instanceof Error ? e.message : String(e);
+          this.logger.logLabeled(
+            "ERROR",
+            "functions",
+            `Failed to read local secrets file ${secretPath}: ${message}`,
+          );
+        }
       }
     }
     // Note - if trigger is undefined, we are loading in 'sequential' mode.
@@ -1945,11 +1950,12 @@ export class FunctionsEmulator implements EmulatorInstance {
     if (!pool.readyForWork(trigger.id, record.backend.runtime)) {
       try {
         await this.startRuntime(record.backend, trigger);
-      } catch (e: any) {
+      } catch (e: unknown) {
+        const message = e instanceof Error ? e.message : String(e);
         this.logger.logLabeled("ERROR", `Failed to handle request for function ${trigger.id}`);
         this.logger.logLabeled(
           "ERROR",
-          `Failed to start functions in ${record.backend.functionsDir}: ${e}`,
+          `Failed to start functions in ${record.backend.functionsDir}: ${message}`,
         );
         return;
       }
diff --git a/src/emulator/functionsEmulatorRuntime.ts b/src/emulator/functionsEmulatorRuntime.ts
index 4b376184fa5..cc57a1c813e 100644
--- a/src/emulator/functionsEmulatorRuntime.ts
+++ b/src/emulator/functionsEmulatorRuntime.ts
@@ -7,6 +7,7 @@ import { pathToFileURL, URL } from "url";
 import * as _ from "lodash";
 
 import { EmulatorLog } from "./types";
+import { getErrMsg, getErrStack } from "../error";
 import { Constants } from "./constants";
 import { findModuleRoot, FunctionsRuntimeBundle, SignatureType } from "./functionsEmulatorShared";
 import { compareVersionStrings, isLocalHost } from "./functionsEmulatorUtils";
@@ -41,7 +42,7 @@ function requireAsync(moduleName: string, opts?: { paths: string[] }): Promise<a
   return new Promise((res, rej) => {
     try {
       res(require(require.resolve(moduleName, opts))); // eslint-disable-line @typescript-eslint/no-var-requires
-    } catch (e: any) {
+    } catch (e: unknown) {
       rej(e);
     }
   });
@@ -51,7 +52,7 @@ function requireResolveAsync(moduleName: string, opts?: { paths: string[] }): Pr
   return new Promise((res, rej) => {
     try {
       res(require.resolve(moduleName, opts));
-    } catch (e: any) {
+    } catch (e: unknown) {
       rej(e);
     }
   });
@@ -289,7 +290,7 @@ function requirePackageJson(): PackageJSON | undefined {
       devDependencies: pkg.devDependencies || {},
     };
     return developerPkgJSON;
-  } catch (err: any) {
+  } catch (err: unknown) {
     return;
   }
 }
@@ -335,7 +336,7 @@ function initializeNetworkFiltering(): void {
             try {
               new URL(arg);
               return arg;
-            } catch (err: any) {
+            } catch (err: unknown) {
               return;
             }
           } else if (typeof arg === "object") {
@@ -406,7 +407,7 @@ async function initializeFirebaseFunctionsStubs(): Promise<void> {
   let httpsProvider: any;
   try {
     httpsProvider = require(httpsProviderV1Resolution);
-  } catch (e: any) {
+  } catch (e: unknown) {
     httpsProvider = require(httpsProviderResolution);
   }
 
@@ -644,7 +645,7 @@ async function runFunction(func: () => Promise<any>): Promise<any> {
   let caughtErr;
   try {
     await func();
-  } catch (err: any) {
+  } catch (err: unknown) {
     caughtErr = err;
   }
   if (caughtErr) {
@@ -757,10 +758,15 @@ async function loadTriggers(): Promise<any> {
   let triggerModule;
   try {
     triggerModule = require(process.cwd());
-  } catch (err: any) {
-    if (err.code !== "ERR_REQUIRE_ESM") {
-      // Try to run diagnostics to see what could've gone wrong before rethrowing the error.
-      await moduleResolutionDetective(err);
+  } catch (err: unknown) {
+    if (typeof err === "object" && err !== null && "code" in err) {
+      const code = (err as { code: unknown }).code;
+      if (code !== "ERR_REQUIRE_ESM") {
+        // Try to run diagnostics to see what could've gone wrong before rethrowing the error.
+        await moduleResolutionDetective(err as unknown as Error);
+        throw err;
+      }
+    } else {
       throw err;
     }
     const modulePath = require.resolve(process.cwd());
@@ -780,7 +786,7 @@ async function handleMessage(message: string) {
   let debug: FunctionsRuntimeBundle["debug"];
   try {
     debug = JSON.parse(message) as FunctionsRuntimeBundle["debug"];
-  } catch (e: any) {
+  } catch (e: unknown) {
     new EmulatorLog("FATAL", "runtime-error", `Got unexpected message body: ${message}`).log();
     await flushAndExit(1);
     return;
@@ -819,11 +825,11 @@ async function main(): Promise<void> {
   await initializeRuntime();
   try {
     functionModule = await loadTriggers();
-  } catch (e: any) {
+  } catch (e: unknown) {
     new EmulatorLog(
       "FATAL",
       "runtime-status",
-      `Failed to initialize and load triggers. This shouldn't happen: ${e.message}`,
+      `Failed to initialize and load triggers. This shouldn't happen: ${getErrMsg(e)}`,
     ).log();
     await flushAndExit(1);
   }
@@ -889,9 +895,9 @@ async function main(): Promise<void> {
         case "http":
           await runHTTPS(trigger, [req, res]);
       }
-    } catch (err: any) {
-      new EmulatorLog("FATAL", "runtime-error", err.stack ? err.stack : err).log();
-      res.status(500).send(err.message);
+    } catch (err: unknown) {
+      new EmulatorLog("FATAL", "runtime-error", getErrStack(err)).log();
+      res.status(500).send(getErrMsg(err));
     }
   });
   app.listen(process.env.PORT, () => {
diff --git a/src/emulator/functionsEmulatorShared.ts b/src/emulator/functionsEmulatorShared.ts
index 852b8d23857..5a9a5009ed2 100644
--- a/src/emulator/functionsEmulatorShared.ts
+++ b/src/emulator/functionsEmulatorShared.ts
@@ -440,7 +440,7 @@ export function findModuleRoot(moduleName: string, filepath: string): string {
         return chunks.join("/");
       }
       break;
-    } catch (err: any) {
+    } catch (err: unknown) {
       /**/
     }
   }
diff --git a/src/emulator/functionsRuntimeWorker.ts b/src/emulator/functionsRuntimeWorker.ts
index a8391d1ccd2..a238223ea81 100644
--- a/src/emulator/functionsRuntimeWorker.ts
+++ b/src/emulator/functionsRuntimeWorker.ts
@@ -272,11 +272,14 @@ export class RuntimeWorker {
       try {
         await Promise.race([this.isSocketReady(), timeout]);
         break;
-      } catch (err: any) {
+      } catch (err: unknown) {
         // Allow us to wait until the server is listening.
-        if (["ECONNREFUSED", "ENOENT"].includes(err?.code)) {
-          await sleep(100);
-          continue;
+        if (typeof err === "object" && err !== null && "code" in err) {
+          const code = (err as { code: unknown }).code;
+          if (typeof code === "string" && ["ECONNREFUSED", "ENOENT"].includes(code)) {
+            await sleep(100);
+            continue;
+          }
         }
         throw err;
       }
diff --git a/src/emulator/hubExport.ts b/src/emulator/hubExport.ts
index 3c3fc629dec..481553c1dc9 100644
--- a/src/emulator/hubExport.ts
+++ b/src/emulator/hubExport.ts
@@ -85,7 +85,7 @@ export class HubExport {
     try {
       mdString = fs.readFileSync(metadataPath, "utf8").toString();
       return JSON.parse(mdString) as ExportMetadata;
-    } catch (err: any) {
+    } catch (err: unknown) {
       // JSON parse errors are unreadable. Throw the original.
       throw new FirebaseError(`Unable to parse metadata file ${metadataPath}: ${mdString}`);
     }
diff --git a/src/emulator/loggingEmulator.ts b/src/emulator/loggingEmulator.ts
index c77e7c8bcf2..45f90e1bca1 100644
--- a/src/emulator/loggingEmulator.ts
+++ b/src/emulator/loggingEmulator.ts
@@ -123,7 +123,7 @@ class WebSocketTransport extends TransportStream {
           try {
             bundle.data = { ...bundle.data, ...JSON.parse(value) };
             return null;
-          } catch (err: any) {
+          } catch (err: unknown) {
             // If the value isn't JSONable, just treat it like a string
             return value;
           }
diff --git a/src/emulator/storage/persistence.ts b/src/emulator/storage/persistence.ts
index fb02bd360e1..1e11d85d431 100644
--- a/src/emulator/storage/persistence.ts
+++ b/src/emulator/storage/persistence.ts
@@ -57,7 +57,7 @@ export class Persistence {
   deleteFile(fileName: string, failSilently = false): void {
     try {
       unlinkSync(this.getDiskPath(fileName));
-    } catch (err: any) {
+    } catch (err: unknown) {
       if (!failSilently) {
         throw err;
       }
diff --git a/src/emulator/storage/rules/runtime.ts b/src/emulator/storage/rules/runtime.ts
index 7a359b5167f..67c8ffdfce5 100644
--- a/src/emulator/storage/rules/runtime.ts
+++ b/src/emulator/storage/rules/runtime.ts
@@ -193,7 +193,7 @@ export class StorageRulesRuntime {
         let rap;
         try {
           rap = JSON.parse(serializedRuntimeActionResponse) as RuntimeActionResponse;
-        } catch (err: any) {
+        } catch (err: unknown) {
           EmulatorLogger.forEmulator(Emulators.STORAGE).log(
             "INFO",
             serializedRuntimeActionResponse,
diff --git a/src/emulator/types.ts b/src/emulator/types.ts
index f33ba83868f..601ce0d6e43 100644
--- a/src/emulator/types.ts
+++ b/src/emulator/types.ts
@@ -284,7 +284,7 @@ export class EmulatorLog {
     let isNotJSON = false;
     try {
       parsedLog = JSON.parse(json);
-    } catch (err: any) {
+    } catch (err: unknown) {
       isNotJSON = true;
     }
 
diff --git a/src/mcp/apps/update_environment/mcp-app.ts b/src/mcp/apps/update_environment/mcp-app.ts
index ab878f8a635..02d601ac58d 100644
--- a/src/mcp/apps/update_environment/mcp-app.ts
+++ b/src/mcp/apps/update_environment/mcp-app.ts
@@ -12,8 +12,13 @@ const searchInput = document.getElementById("search-input") as HTMLInputElement;
 const submitBtn = document.getElementById("submit-btn") as HTMLButtonElement;
 const statusBox = document.getElementById("status-box") as HTMLDivElement;
 
-let projects: any[] = [];
-let filteredProjects: any[] = [];
+interface Project {
+  projectId: string;
+  displayName?: string;
+}
+
+let projects: Project[] = [];
+let filteredProjects: Project[] = [];
 let selectedProjectId: string | null = null;
 
 const envProjectIdEl = document.getElementById("env-project-id") as HTMLSpanElement;
diff --git a/src/mcp/resources/update_environment_ui.ts b/src/mcp/resources/update_environment_ui.ts
index 76f10d3265e..f78d7c79a12 100644
--- a/src/mcp/resources/update_environment_ui.ts
+++ b/src/mcp/resources/update_environment_ui.ts
@@ -25,8 +25,9 @@ export const update_environment_ui = resource(
           },
         ],
       };
-    } catch (e: any) {
-      throw new Error(`Failed to load Update Environment UI: ${e.message}`);
+    } catch (e: unknown) {
+      const message = e instanceof Error ? e.message : String(e);
+      throw new Error(`Failed to load Update Environment UI: ${message}`);
     }
   },
 );
diff --git a/src/mcp/util.ts b/src/mcp/util.ts
index fe3c198b1ca..cda84f67583 100644
--- a/src/mcp/util.ts
+++ b/src/mcp/util.ts
@@ -23,7 +23,7 @@ import { timeoutFallback } from "../timeout";
  * Converts data to a CallToolResult.
  */
 export function toContent(
-  data: any,
+  data: unknown,
   options?: { format?: "json" | "yaml"; contentPrefix?: string; contentSuffix?: string },
 ): CallToolResult {
   if (typeof data === "string") return { content: [{ type: "text", text: data }] };
@@ -42,8 +42,8 @@ export function toContent(
   const suffix = options?.contentSuffix || "";
   return {
     content: [{ type: "text", text: `${prefix}${text}${suffix}` }],
-    structuredContent: data,
-  } as CallToolResult & { structuredContent: any };
+    structuredContent: data as { [key: string]: unknown },
+  };
 }
 
 /**