diff --git a/packages/artifact/__tests__/artifactTwirpClient.test.ts b/packages/artifact/__tests__/artifactTwirpClient.test.ts
index 035031e1..882c7ef4 100644
--- a/packages/artifact/__tests__/artifactTwirpClient.test.ts
+++ b/packages/artifact/__tests__/artifactTwirpClient.test.ts
@@ -30,24 +30,30 @@ describe('ArtifactHttpClient', () => {
     it('should mask signed_upload_url', () => {
       const response: CreateArtifactResponse = {
         ok: true,
-        signedUploadUrl: 'https://example.com/upload?se=2025-03-05T16%3A47%3A23Z&sig=secret-token'
+        signedUploadUrl:
+          'https://example.com/upload?se=2025-03-05T16%3A47%3A23Z&sig=secret-token'
       }
 
       client.maskSecretUrls(response)
 
       expect(setSecret).toHaveBeenCalledWith('secret-token')
-      expect(debug).toHaveBeenCalledWith('Masked signed_upload_url: https://example.com/upload?se=2025-03-05T16%3A47%3A23Z&sig=***')
+      expect(debug).toHaveBeenCalledWith(
+        'Masked signed_upload_url: https://example.com/upload?se=2025-03-05T16%3A47%3A23Z&sig=***'
+      )
     })
 
     it('should mask signed_download_url', () => {
       const response: GetSignedArtifactURLResponse = {
-        signedUrl: 'https://example.com/download?se=2025-03-05T16%3A47%3A23Z&sig=secret-token'
+        signedUrl:
+          'https://example.com/download?se=2025-03-05T16%3A47%3A23Z&sig=secret-token'
       }
 
       client.maskSecretUrls(response)
 
       expect(setSecret).toHaveBeenCalledWith('secret-token')
-      expect(debug).toHaveBeenCalledWith('Masked signed_download_url: https://example.com/download?se=2025-03-05T16%3A47%3A23Z&sig=***')
+      expect(debug).toHaveBeenCalledWith(
+        'Masked signed_url: https://example.com/download?se=2025-03-05T16%3A47%3A23Z&sig=***'
+      )
     })
 
     it('should not call setSecret if URLs are missing', () => {
@@ -61,24 +67,30 @@ describe('ArtifactHttpClient', () => {
     it('should mask only the sensitive token part of signed_upload_url', () => {
       const response: CreateArtifactResponse = {
         ok: true,
-        signedUploadUrl: 'https://example.com/upload?se=2025-03-05T16%3A47%3A23Z&sig=secret-token'
+        signedUploadUrl:
+          'https://example.com/upload?se=2025-03-05T16%3A47%3A23Z&sig=secret-token'
       }
 
       client.maskSecretUrls(response)
 
       expect(setSecret).toHaveBeenCalledWith('secret-token')
-      expect(debug).toHaveBeenCalledWith('Masked signed_upload_url: https://example.com/upload?se=2025-03-05T16%3A47%3A23Z&sig=***')
+      expect(debug).toHaveBeenCalledWith(
+        'Masked signed_upload_url: https://example.com/upload?se=2025-03-05T16%3A47%3A23Z&sig=***'
+      )
     })
 
     it('should mask only the sensitive token part of signed_download_url', () => {
       const response: GetSignedArtifactURLResponse = {
-        signedUrl: 'https://example.com/download?se=2025-03-05T16%3A47%3A23Z&sig=secret-token'
+        signedUrl:
+          'https://example.com/download?se=2025-03-05T16%3A47%3A23Z&sig=secret-token'
       }
 
       client.maskSecretUrls(response)
 
       expect(setSecret).toHaveBeenCalledWith('secret-token')
-      expect(debug).toHaveBeenCalledWith('Masked signed_download_url: https://example.com/download?se=2025-03-05T16%3A47%3A23Z&sig=***')
+      expect(debug).toHaveBeenCalledWith(
+        'Masked signed_url: https://example.com/download?se=2025-03-05T16%3A47%3A23Z&sig=***'
+      )
     })
   })
 })
diff --git a/packages/artifact/src/internal/shared/artifact-twirp-client.ts b/packages/artifact/src/internal/shared/artifact-twirp-client.ts
index 1d3e8c69..2d389114 100644
--- a/packages/artifact/src/internal/shared/artifact-twirp-client.ts
+++ b/packages/artifact/src/internal/shared/artifact-twirp-client.ts
@@ -1,6 +1,6 @@
 import {HttpClient, HttpClientResponse, HttpCodes} from '@actions/http-client'
 import {BearerCredentialHandler} from '@actions/http-client/lib/auth'
-import {setSecret, info, debug, maskSigUrl} from '@actions/core'
+import {setSecret, info, debug} from '@actions/core'
 import {ArtifactServiceClientJSON} from '../../generated'
 import {getResultsServiceUrl, getRuntimeToken} from './config'
 import {getUserAgentString} from './user-agent'
@@ -74,14 +74,27 @@ export class ArtifactHttpClient implements Rpc {
     }
   }
 
+  /**
+   * Masks the `sig` parameter in a URL and sets it as a secret.
+   * @param url The URL containing the `sig` parameter.
+   * @param urlType The type of the URL (e.g., 'signed_upload_url', 'signed_download_url').
+   */
+  maskSigUrl(url: string, urlType: string): void {
+    const sigMatch = url.match(/[?&]sig=([^&]+)/)
+    if (sigMatch) {
+      setSecret(sigMatch[1])
+      debug(`Masked ${urlType}: ${url.replace(sigMatch[1], '***')}`)
+    }
+  }
+
   maskSecretUrls(
     body: CreateArtifactResponse | GetSignedArtifactURLResponse
   ): void {
     if ('signedUploadUrl' in body && body.signedUploadUrl) {
-      maskSigUrl(body.signedUploadUrl, 'signed_upload_url')
+      this.maskSigUrl(body.signedUploadUrl, 'signed_upload_url')
     }
     if ('signedUrl' in body && body.signedUrl) {
-      maskSigUrl(body.signedUrl, 'signed_url')
+      this.maskSigUrl(body.signedUrl, 'signed_url')
     }
   }
 
diff --git a/packages/cache/__tests__/cacheTwirpClient.test.ts b/packages/cache/__tests__/cacheTwirpClient.test.ts
index dd38e8fe..e981ce1a 100644
--- a/packages/cache/__tests__/cacheTwirpClient.test.ts
+++ b/packages/cache/__tests__/cacheTwirpClient.test.ts
@@ -16,12 +16,12 @@ describe('CacheServiceClient', () => {
 
   beforeEach(() => {
     jest.clearAllMocks()
-    process.env['ACTIONS_RUNTIME_TOKEN'] = 'test-token' // <-- set the required env variable
+    process.env['ACTIONS_RUNTIME_TOKEN'] = 'test-token'
     client = new CacheServiceClient('test-agent')
   })
 
   afterEach(() => {
-    delete process.env['ACTIONS_RUNTIME_TOKEN'] // <-- clean up after tests
+    delete process.env['ACTIONS_RUNTIME_TOKEN']
   })
 
   describe('maskSecretUrls', () => {
@@ -36,7 +36,7 @@ describe('CacheServiceClient', () => {
 
       expect(setSecret).toHaveBeenCalledWith('secret-token')
       expect(debug).toHaveBeenCalledWith(
-        'Masked signedUploadUrl: https://example.com/upload?se=2025-03-05T16%3A47%3A23Z&sig=***'
+        'Masked signed_upload_url: https://example.com/upload?se=2025-03-05T16%3A47%3A23Z&sig=***'
       )
     })
 
@@ -52,7 +52,7 @@ describe('CacheServiceClient', () => {
 
       expect(setSecret).toHaveBeenCalledWith('secret-token')
       expect(debug).toHaveBeenCalledWith(
-        'Masked signedDownloadUrl: https://example.com/download?se=2025-03-05T16%3A47%3A23Z&sig=***'
+        'Masked signed_download_url: https://example.com/download?se=2025-03-05T16%3A47%3A23Z&sig=***'
       )
     })
 
@@ -75,7 +75,7 @@ describe('CacheServiceClient', () => {
 
       expect(setSecret).toHaveBeenCalledWith('secret-token')
       expect(debug).toHaveBeenCalledWith(
-        'Masked signedUploadUrl: https://example.com/upload?se=2025-03-05T16%3A47%3A23Z&sig=***'
+        'Masked signed_upload_url: https://example.com/upload?se=2025-03-05T16%3A47%3A23Z&sig=***'
       )
     })
 
@@ -91,7 +91,7 @@ describe('CacheServiceClient', () => {
 
       expect(setSecret).toHaveBeenCalledWith('secret-token')
       expect(debug).toHaveBeenCalledWith(
-        'Masked signedDownloadUrl: https://example.com/download?se=2025-03-05T16%3A47%3A23Z&sig=***'
+        'Masked signed_download_url: https://example.com/download?se=2025-03-05T16%3A47%3A23Z&sig=***'
       )
     })
   })
diff --git a/packages/cache/package.json b/packages/cache/package.json
index 3a200f89..4667849d 100644
--- a/packages/cache/package.json
+++ b/packages/cache/package.json
@@ -31,7 +31,8 @@
   "scripts": {
     "audit-moderate": "npm install && npm audit --json --audit-level=moderate > audit.json",
     "test": "echo \"Error: run tests from root\" && exit 1",
-    "tsc": "tsc"
+    "tsc": "tsc",
+    "clean": "rm -rf node_modules lib"
   },
   "bugs": {
     "url": "https://github.com/actions/toolkit/issues"
@@ -46,6 +47,7 @@
     "@azure/ms-rest-js": "^2.6.0",
     "@azure/storage-blob": "^12.13.0",
     "@protobuf-ts/plugin": "^2.9.4",
+    "@types/node": "^22.13.9",
     "semver": "^6.3.1"
   },
   "devDependencies": {
diff --git a/packages/cache/src/internal/shared/cacheTwirpClient.ts b/packages/cache/src/internal/shared/cacheTwirpClient.ts
index 9c121121..2c8acbe2 100644
--- a/packages/cache/src/internal/shared/cacheTwirpClient.ts
+++ b/packages/cache/src/internal/shared/cacheTwirpClient.ts
@@ -1,4 +1,4 @@
-import {info, debug, maskSigUrl} from '@actions/core'
+import {info, debug, setSecret} from '@actions/core'
 import {getUserAgentString} from './user-agent'
 import {NetworkError, UsageError} from './errors'
 import {getCacheServiceURL} from '../config'
@@ -153,14 +153,27 @@ export class CacheServiceClient implements Rpc {
     throw new Error(`Request failed`)
   }
 
+  /**
+   * Masks the `sig` parameter in a URL and sets it as a secret.
+   * @param url The URL containing the `sig` parameter.
+   * @param urlType The type of the URL (e.g., 'signed_upload_url', 'signed_download_url').
+   */
+  maskSigUrl(url: string, urlType: string): void {
+    const sigMatch = url.match(/[?&]sig=([^&]+)/)
+    if (sigMatch) {
+      setSecret(sigMatch[1])
+      debug(`Masked ${urlType}: ${url.replace(sigMatch[1], '***')}`)
+    }
+  }
+
   maskSecretUrls(
     body: CreateCacheEntryResponse | GetCacheEntryDownloadURLResponse
   ): void {
     if ('signedUploadUrl' in body && body.signedUploadUrl) {
-      maskSigUrl(body.signedUploadUrl, 'signedUploadUrl')
+      this.maskSigUrl(body.signedUploadUrl, 'signed_upload_url')
     }
     if ('signedDownloadUrl' in body && body.signedDownloadUrl) {
-      maskSigUrl(body.signedDownloadUrl, 'signedDownloadUrl')
+      this.maskSigUrl(body.signedDownloadUrl, 'signed_download_url')
     }
   }
 
diff --git a/packages/core/src/core.ts b/packages/core/src/core.ts
index 12359d0a..0a141693 100644
--- a/packages/core/src/core.ts
+++ b/packages/core/src/core.ts
@@ -391,19 +391,3 @@ export {toPosixPath, toWin32Path, toPlatformPath} from './path-utils'
  * Platform utilities exports
  */
 export * as platform from './platform'
-
-/**
- * Masks the `sig` parameter in a URL and sets it as a secret.
- * @param url The URL containing the `sig` parameter.
- * @param urlType The type of the URL (e.g., 'signed_upload_url', 'signed_download_url').
- * @returns The URL with the `sig` parameter masked.
- */
-export function maskSigUrl(url: string, urlType: string): string {
-  const sigMatch = url.match(/[?&]sig=([^&]+)/)
-  if (sigMatch) {
-    setSecret(sigMatch[1])
-    debug(`Masked ${urlType}: ${url.replace(sigMatch[1], '***')}`)
-    return url.replace(sigMatch[1], '***')
-  }
-  return url
-}