diff --git a/packages/artifact/__tests__/util.test.ts b/packages/artifact/__tests__/util.test.ts
index 76fe4e18..2649662e 100644
--- a/packages/artifact/__tests__/util.test.ts
+++ b/packages/artifact/__tests__/util.test.ts
@@ -1,5 +1,7 @@
 import * as config from '../src/internal/shared/config'
 import * as util from '../src/internal/shared/util'
+import {maskSigUrl, maskSecretUrls} from '../src/internal/shared/util'
+import {setSecret, debug} from '@actions/core'
 
 export const testRuntimeToken =
   'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwic2NwIjoiQWN0aW9ucy5FeGFtcGxlIEFjdGlvbnMuQW5vdGhlckV4YW1wbGU6dGVzdCBBY3Rpb25zLlJlc3VsdHM6Y2U3ZjU0YzctNjFjNy00YWFlLTg4N2YtMzBkYTQ3NWY1ZjFhOmNhMzk1MDg1LTA0MGEtNTI2Yi0yY2U4LWJkYzg1ZjY5Mjc3NCIsImlhdCI6MTUxNjIzOTAyMn0.XYnI_wHPBlUi1mqYveJnnkJhp4dlFjqxzRmISPsqfw8'
@@ -59,3 +61,159 @@ describe('get-backend-ids-from-token', () => {
     )
   })
 })
+
+jest.mock('@actions/core')
+
+describe('maskSigUrl', () => {
+  beforeEach(() => {
+    jest.clearAllMocks()
+  })
+
+  it('does nothing if no sig parameter is present', () => {
+    const url = 'https://example.com'
+    maskSigUrl(url)
+    expect(setSecret).not.toHaveBeenCalled()
+  })
+
+  it('masks the sig parameter in the middle of the URL and sets it as a secret', () => {
+    const url = 'https://example.com/?param1=value1&sig=12345&param2=value2'
+    maskSigUrl(url)
+    expect(setSecret).toHaveBeenCalledWith('12345')
+    expect(setSecret).toHaveBeenCalledWith(encodeURIComponent('12345'))
+  })
+
+  it('does nothing if the URL is empty', () => {
+    const url = ''
+    maskSigUrl(url)
+    expect(setSecret).not.toHaveBeenCalled()
+  })
+
+  it('handles URLs with fragments', () => {
+    const url = 'https://example.com?sig=12345#fragment'
+    maskSigUrl(url)
+    expect(setSecret).toHaveBeenCalledWith('12345')
+    expect(setSecret).toHaveBeenCalledWith(encodeURIComponent('12345'))
+  })
+})
+
+describe('maskSigUrl handles special characters in signatures', () => {
+  beforeEach(() => {
+    jest.clearAllMocks()
+  })
+
+  it('handles signatures with slashes', () => {
+    const url = 'https://example.com/?sig=abc/123'
+    maskSigUrl(url)
+    expect(setSecret).toHaveBeenCalledWith('abc/123')
+    expect(setSecret).toHaveBeenCalledWith('abc%2F123')
+  })
+
+  it('handles signatures with plus signs', () => {
+    const url = 'https://example.com/?sig=abc+123'
+    maskSigUrl(url)
+    expect(setSecret).toHaveBeenCalledWith('abc 123')
+    expect(setSecret).toHaveBeenCalledWith('abc%20123')
+  })
+
+  it('handles signatures with equals signs', () => {
+    const url = 'https://example.com/?sig=abc=123'
+    maskSigUrl(url)
+    expect(setSecret).toHaveBeenCalledWith('abc=123')
+    expect(setSecret).toHaveBeenCalledWith('abc%3D123')
+  })
+
+  it('handles already percent-encoded signatures', () => {
+    const url = 'https://example.com/?sig=abc%2F123%3D'
+    maskSigUrl(url)
+    expect(setSecret).toHaveBeenCalledWith('abc/123=')
+    expect(setSecret).toHaveBeenCalledWith('abc%2F123%3D')
+  })
+
+  it('handles complex Azure SAS signatures', () => {
+    const url =
+      'https://example.com/container/file.txt?sig=nXyQIUj%2F%2F06Cxt80pBRYiiJlYqtPYg5sz%2FvEh5iHAhw%3D&se=2023-12-31'
+    maskSigUrl(url)
+    expect(setSecret).toHaveBeenCalledWith(
+      'nXyQIUj//06Cxt80pBRYiiJlYqtPYg5sz/vEh5iHAhw='
+    )
+    expect(setSecret).toHaveBeenCalledWith(
+      'nXyQIUj%2F%2F06Cxt80pBRYiiJlYqtPYg5sz%2FvEh5iHAhw%3D'
+    )
+  })
+
+  it('handles signatures with multiple special characters', () => {
+    const url = 'https://example.com/?sig=a/b+c=d&e=f'
+    maskSigUrl(url)
+    expect(setSecret).toHaveBeenCalledWith('a/b c=d')
+    expect(setSecret).toHaveBeenCalledWith('a%2Fb%20c%3Dd')
+  })
+})
+
+describe('maskSecretUrls', () => {
+  beforeEach(() => {
+    jest.clearAllMocks()
+  })
+
+  it('masks sig parameters in signed_upload_url and signed_url', () => {
+    const body = {
+      signed_upload_url: 'https://upload.com?sig=upload123',
+      signed_url: 'https://download.com?sig=download123'
+    }
+    maskSecretUrls(body)
+    expect(setSecret).toHaveBeenCalledWith('upload123')
+    expect(setSecret).toHaveBeenCalledWith(encodeURIComponent('upload123'))
+    expect(setSecret).toHaveBeenCalledWith('download123')
+    expect(setSecret).toHaveBeenCalledWith(encodeURIComponent('download123'))
+  })
+
+  it('handles case where only upload_url is present', () => {
+    const body = {
+      signed_upload_url: 'https://upload.com?sig=upload123'
+    }
+    maskSecretUrls(body)
+    expect(setSecret).toHaveBeenCalledWith('upload123')
+    expect(setSecret).toHaveBeenCalledWith(encodeURIComponent('upload123'))
+  })
+
+  it('handles case where only download_url is present', () => {
+    const body = {
+      signed_url: 'https://download.com?sig=download123'
+    }
+    maskSecretUrls(body)
+    expect(setSecret).toHaveBeenCalledWith('download123')
+    expect(setSecret).toHaveBeenCalledWith(encodeURIComponent('download123'))
+  })
+
+  it('handles case where URLs do not contain sig parameters', () => {
+    const body = {
+      signed_upload_url: 'https://upload.com?token=abc',
+      signed_url: 'https://download.com?token=xyz'
+    }
+    maskSecretUrls(body)
+    expect(setSecret).not.toHaveBeenCalled()
+  })
+
+  it('handles empty string URLs', () => {
+    const body = {
+      signed_upload_url: '',
+      signed_url: ''
+    }
+    maskSecretUrls(body)
+    expect(setSecret).not.toHaveBeenCalled()
+  })
+
+  it('does nothing if body is not an object or is null', () => {
+    maskSecretUrls(null)
+    expect(debug).toHaveBeenCalledWith('body is not an object or is null')
+    expect(setSecret).not.toHaveBeenCalled()
+  })
+
+  it('does nothing if signed_upload_url and signed_url are not strings', () => {
+    const body = {
+      signed_upload_url: 123,
+      signed_url: 456
+    }
+    maskSecretUrls(body)
+    expect(setSecret).not.toHaveBeenCalled()
+  })
+})
diff --git a/packages/artifact/src/internal/shared/artifact-twirp-client.ts b/packages/artifact/src/internal/shared/artifact-twirp-client.ts
index 00c65bc7..57499125 100644
--- a/packages/artifact/src/internal/shared/artifact-twirp-client.ts
+++ b/packages/artifact/src/internal/shared/artifact-twirp-client.ts
@@ -5,6 +5,7 @@ import {ArtifactServiceClientJSON} from '../../generated'
 import {getResultsServiceUrl, getRuntimeToken} from './config'
 import {getUserAgentString} from './user-agent'
 import {NetworkError, UsageError} from './errors'
+import {maskSecretUrls} from './util'
 
 // The twirp http client must implement this interface
 interface Rpc {
@@ -86,6 +87,7 @@ class ArtifactHttpClient implements Rpc {
         debug(`[Response] - ${response.message.statusCode}`)
         debug(`Headers: ${JSON.stringify(response.message.headers, null, 2)}`)
         const body = JSON.parse(rawBody)
+        maskSecretUrls(body)
         debug(`Body: ${JSON.stringify(body, null, 2)}`)
         if (this.isSuccessStatusCode(statusCode)) {
           return {response, body}
diff --git a/packages/artifact/src/internal/shared/util.ts b/packages/artifact/src/internal/shared/util.ts
index 07392b36..67120e27 100644
--- a/packages/artifact/src/internal/shared/util.ts
+++ b/packages/artifact/src/internal/shared/util.ts
@@ -1,6 +1,7 @@
 import * as core from '@actions/core'
 import {getRuntimeToken} from './config'
 import jwt_decode from 'jwt-decode'
+import {debug, setSecret} from '@actions/core'
 
 export interface BackendIds {
   workflowRunBackendId: string
@@ -69,3 +70,76 @@ export function getBackendIdsFromToken(): BackendIds {
 
   throw InvalidJwtError
 }
+
+/**
+ * Masks the `sig` parameter in a URL and sets it as a secret.
+ *
+ * @param url - The URL containing the signature parameter to mask
+ * @remarks
+ * This function attempts to parse the provided URL and identify the 'sig' query parameter.
+ * If found, it registers both the raw and URL-encoded signature values as secrets using
+ * the Actions `setSecret` API, which prevents them from being displayed in logs.
+ *
+ * The function handles errors gracefully if URL parsing fails, logging them as debug messages.
+ *
+ * @example
+ * ```typescript
+ * // Mask a signature in an Azure SAS token URL
+ * maskSigUrl('https://example.blob.core.windows.net/container/file.txt?sig=abc123&se=2023-01-01');
+ * ```
+ */
+export function maskSigUrl(url: string): void {
+  if (!url) return
+  try {
+    const parsedUrl = new URL(url)
+    const signature = parsedUrl.searchParams.get('sig')
+    if (signature) {
+      setSecret(signature)
+      setSecret(encodeURIComponent(signature))
+    }
+  } catch (error) {
+    debug(
+      `Failed to parse URL: ${url} ${
+        error instanceof Error ? error.message : String(error)
+      }`
+    )
+  }
+}
+
+/**
+ * Masks sensitive information in URLs containing signature parameters.
+ * Currently supports masking 'sig' parameters in the 'signed_upload_url'
+ * and 'signed_download_url' properties of the provided object.
+ *
+ * @param body - The object should contain a signature
+ * @remarks
+ * This function extracts URLs from the object properties and calls maskSigUrl
+ * on each one to redact sensitive signature information. The function doesn't
+ * modify the original object; it only marks the signatures as secrets for
+ * logging purposes.
+ *
+ * @example
+ * ```typescript
+ * const responseBody = {
+ *   signed_upload_url: 'https://example.com?sig=abc123',
+ *   signed_download_url: 'https://example.com?sig=def456'
+ * };
+ * maskSecretUrls(responseBody);
+ * ```
+ */
+export function maskSecretUrls(body: Record<string, unknown> | null): void {
+  if (typeof body !== 'object' || body === null) {
+    debug('body is not an object or is null')
+    return
+  }
+
+  if (
+    'signed_upload_url' in body &&
+    typeof body.signed_upload_url === 'string'
+  ) {
+    maskSigUrl(body.signed_upload_url)
+  }
+  if ('signed_url' in body && typeof body.signed_url === 'string') {
+    maskSigUrl(body.signed_url)
+  }
+}
diff --git a/packages/cache/__tests__/util.test.ts b/packages/cache/__tests__/util.test.ts
new file mode 100644
index 00000000..3ba3bba7
--- /dev/null
+++ b/packages/cache/__tests__/util.test.ts
@@ -0,0 +1,158 @@
+import {maskSigUrl, maskSecretUrls} from '../src/internal/shared/util'
+import {setSecret, debug} from '@actions/core'
+
+jest.mock('@actions/core')
+
+describe('maskSigUrl', () => {
+  beforeEach(() => {
+    jest.clearAllMocks()
+  })
+
+  it('does nothing if no sig parameter is present', () => {
+    const url = 'https://example.com'
+    maskSigUrl(url)
+    expect(setSecret).not.toHaveBeenCalled()
+  })
+
+  it('masks the sig parameter in the middle of the URL and sets it as a secret', () => {
+    const url = 'https://example.com/?param1=value1&sig=12345&param2=value2'
+    maskSigUrl(url)
+    expect(setSecret).toHaveBeenCalledWith('12345')
+    expect(setSecret).toHaveBeenCalledWith(encodeURIComponent('12345'))
+  })
+
+  it('does nothing if the URL is empty', () => {
+    const url = ''
+    maskSigUrl(url)
+    expect(setSecret).not.toHaveBeenCalled()
+  })
+
+  it('handles URLs with fragments', () => {
+    const url = 'https://example.com?sig=12345#fragment'
+    maskSigUrl(url)
+    expect(setSecret).toHaveBeenCalledWith('12345')
+    expect(setSecret).toHaveBeenCalledWith(encodeURIComponent('12345'))
+  })
+})
+
+describe('maskSigUrl handles special characters in signatures', () => {
+  beforeEach(() => {
+    jest.clearAllMocks()
+  })
+
+  it('handles signatures with slashes', () => {
+    const url = 'https://example.com/?sig=abc/123'
+    maskSigUrl(url)
+    expect(setSecret).toHaveBeenCalledWith('abc/123')
+    expect(setSecret).toHaveBeenCalledWith('abc%2F123')
+  })
+
+  it('handles signatures with plus signs', () => {
+    const url = 'https://example.com/?sig=abc+123'
+    maskSigUrl(url)
+    expect(setSecret).toHaveBeenCalledWith('abc 123')
+    expect(setSecret).toHaveBeenCalledWith('abc%20123')
+  })
+
+  it('handles signatures with equals signs', () => {
+    const url = 'https://example.com/?sig=abc=123'
+    maskSigUrl(url)
+    expect(setSecret).toHaveBeenCalledWith('abc=123')
+    expect(setSecret).toHaveBeenCalledWith('abc%3D123')
+  })
+
+  it('handles already percent-encoded signatures', () => {
+    const url = 'https://example.com/?sig=abc%2F123%3D'
+    maskSigUrl(url)
+    expect(setSecret).toHaveBeenCalledWith('abc/123=')
+    expect(setSecret).toHaveBeenCalledWith('abc%2F123%3D')
+  })
+
+  it('handles complex Azure SAS signatures', () => {
+    const url =
+      'https://example.com/container/file.txt?sig=nXyQIUj%2F%2F06Cxt80pBRYiiJlYqtPYg5sz%2FvEh5iHAhw%3D&se=2023-12-31'
+    maskSigUrl(url)
+    expect(setSecret).toHaveBeenCalledWith(
+      'nXyQIUj//06Cxt80pBRYiiJlYqtPYg5sz/vEh5iHAhw='
+    )
+    expect(setSecret).toHaveBeenCalledWith(
+      'nXyQIUj%2F%2F06Cxt80pBRYiiJlYqtPYg5sz%2FvEh5iHAhw%3D'
+    )
+  })
+
+  it('handles signatures with multiple special characters', () => {
+    const url = 'https://example.com/?sig=a/b+c=d&e=f'
+    maskSigUrl(url)
+    expect(setSecret).toHaveBeenCalledWith('a/b c=d')
+    expect(setSecret).toHaveBeenCalledWith('a%2Fb%20c%3Dd')
+  })
+})
+
+describe('maskSecretUrls', () => {
+  beforeEach(() => {
+    jest.clearAllMocks()
+  })
+
+  it('masks sig parameters in signed_upload_url and signed_download_url', () => {
+    const body = {
+      signed_upload_url: 'https://upload.com?sig=upload123',
+      signed_download_url: 'https://download.com?sig=download123'
+    }
+    maskSecretUrls(body)
+    expect(setSecret).toHaveBeenCalledWith('upload123')
+    expect(setSecret).toHaveBeenCalledWith(encodeURIComponent('upload123'))
+    expect(setSecret).toHaveBeenCalledWith('download123')
+    expect(setSecret).toHaveBeenCalledWith(encodeURIComponent('download123'))
+  })
+
+  it('handles case where only upload_url is present', () => {
+    const body = {
+      signed_upload_url: 'https://upload.com?sig=upload123'
+    }
+    maskSecretUrls(body)
+    expect(setSecret).toHaveBeenCalledWith('upload123')
+    expect(setSecret).toHaveBeenCalledWith(encodeURIComponent('upload123'))
+  })
+
+  it('handles case where only download_url is present', () => {
+    const body = {
+      signed_download_url: 'https://download.com?sig=download123'
+    }
+    maskSecretUrls(body)
+    expect(setSecret).toHaveBeenCalledWith('download123')
+    expect(setSecret).toHaveBeenCalledWith(encodeURIComponent('download123'))
+  })
+
+  it('handles case where URLs do not contain sig parameters', () => {
+    const body = {
+      signed_upload_url: 'https://upload.com?token=abc',
+      signed_download_url: 'https://download.com?token=xyz'
+    }
+    maskSecretUrls(body)
+    expect(setSecret).not.toHaveBeenCalled()
+  })
+
+  it('handles empty string URLs', () => {
+    const body = {
+      signed_upload_url: '',
+      signed_download_url: ''
+    }
+    maskSecretUrls(body)
+    expect(setSecret).not.toHaveBeenCalled()
+  })
+
+  it('does nothing if body is not an object or is null', () => {
+    maskSecretUrls(null)
+    expect(debug).toHaveBeenCalledWith('body is not an object or is null')
+    expect(setSecret).not.toHaveBeenCalled()
+  })
+
+  it('does nothing if signed_upload_url and signed_download_url are not strings', () => {
+    const body = {
+      signed_upload_url: 123,
+      signed_download_url: 456
+    }
+    maskSecretUrls(body)
+    expect(setSecret).not.toHaveBeenCalled()
+  })
+})
diff --git a/packages/cache/package-lock.json b/packages/cache/package-lock.json
index 3dcc20d9..8d075bbd 100644
--- a/packages/cache/package-lock.json
+++ b/packages/cache/package-lock.json
@@ -21,6 +21,7 @@
         "semver": "^6.3.1"
       },
       "devDependencies": {
+        "@types/node": "^22.13.9",
         "@types/semver": "^6.0.0",
         "typescript": "^5.2.2"
       }
@@ -324,9 +325,13 @@
       }
     },
     "node_modules/@types/node": {
-      "version": "20.4.6",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-20.4.6.tgz",
-      "integrity": "sha512-q0RkvNgMweWWIvSMDiXhflGUKMdIxBo2M2tYM/0kEGDueQByFzK4KZAgu5YHGFNxziTlppNpTIBcqHQAxlfHdA=="
+      "version": "22.13.9",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-22.13.9.tgz",
+      "integrity": "sha512-acBjXdRJ3A6Pb3tqnw9HZmyR3Fiol3aGxRCK1x3d+6CDAMjl7I649wpSd+yNURCjbOUGu9tqtLKnTGxmK6CyGw==",
+      "license": "MIT",
+      "dependencies": {
+        "undici-types": "~6.20.0"
+      }
     },
     "node_modules/@types/node-fetch": {
       "version": "2.6.4",
@@ -548,6 +553,12 @@
         "node": ">=14.17"
       }
     },
+    "node_modules/undici-types": {
+      "version": "6.20.0",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-6.20.0.tgz",
+      "integrity": "sha512-Ny6QZ2Nju20vw1SRHe3d9jVu6gJ+4e3+MMpqu7pqE5HT6WsTSlce++GQmK5UXS8mzV8DSYHrQH+Xrf2jVcuKNg==",
+      "license": "MIT"
+    },
     "node_modules/webidl-conversions": {
       "version": "3.0.1",
       "resolved": "https://registry.npmjs.org/webidl-conversions/-/webidl-conversions-3.0.1.tgz",
@@ -824,9 +835,12 @@
       }
     },
     "@types/node": {
-      "version": "20.4.6",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-20.4.6.tgz",
-      "integrity": "sha512-q0RkvNgMweWWIvSMDiXhflGUKMdIxBo2M2tYM/0kEGDueQByFzK4KZAgu5YHGFNxziTlppNpTIBcqHQAxlfHdA=="
+      "version": "22.13.9",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-22.13.9.tgz",
+      "integrity": "sha512-acBjXdRJ3A6Pb3tqnw9HZmyR3Fiol3aGxRCK1x3d+6CDAMjl7I649wpSd+yNURCjbOUGu9tqtLKnTGxmK6CyGw==",
+      "requires": {
+        "undici-types": "~6.20.0"
+      }
     },
     "@types/node-fetch": {
       "version": "2.6.4",
@@ -993,6 +1007,11 @@
       "integrity": "sha512-mI4WrpHsbCIcwT9cF4FZvr80QUeKvsUsUvKDoR+X/7XHQH98xYD8YHZg7ANtz2GtZt/CBq2QJ0thkGJMHfqc1w==",
       "dev": true
     },
+    "undici-types": {
+      "version": "6.20.0",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-6.20.0.tgz",
+      "integrity": "sha512-Ny6QZ2Nju20vw1SRHe3d9jVu6gJ+4e3+MMpqu7pqE5HT6WsTSlce++GQmK5UXS8mzV8DSYHrQH+Xrf2jVcuKNg=="
+    },
     "webidl-conversions": {
       "version": "3.0.1",
       "resolved": "https://registry.npmjs.org/webidl-conversions/-/webidl-conversions-3.0.1.tgz",
diff --git a/packages/cache/package.json b/packages/cache/package.json
index 3a200f89..9b8b0ac6 100644
--- a/packages/cache/package.json
+++ b/packages/cache/package.json
@@ -49,6 +49,7 @@
     "semver": "^6.3.1"
   },
   "devDependencies": {
+    "@types/node": "^22.13.9",
     "@types/semver": "^6.0.0",
     "typescript": "^5.2.2"
   }
diff --git a/packages/cache/src/internal/shared/cacheTwirpClient.ts b/packages/cache/src/internal/shared/cacheTwirpClient.ts
index 69d9a8fc..f6c2af61 100644
--- a/packages/cache/src/internal/shared/cacheTwirpClient.ts
+++ b/packages/cache/src/internal/shared/cacheTwirpClient.ts
@@ -6,6 +6,7 @@ import {getRuntimeToken} from '../cacheUtils'
 import {BearerCredentialHandler} from '@actions/http-client/lib/auth'
 import {HttpClient, HttpClientResponse, HttpCodes} from '@actions/http-client'
 import {CacheServiceClientJSON} from '../../generated/results/api/v1/cache.twirp-client'
+import {maskSecretUrls} from './util'
 
 // The twirp http client must implement this interface
 interface Rpc {
@@ -94,6 +95,7 @@ class CacheServiceClient implements Rpc {
         debug(`[Response] - ${response.message.statusCode}`)
         debug(`Headers: ${JSON.stringify(response.message.headers, null, 2)}`)
         const body = JSON.parse(rawBody)
+        maskSecretUrls(body)
         debug(`Body: ${JSON.stringify(body, null, 2)}`)
         if (this.isSuccessStatusCode(statusCode)) {
           return {response, body}
diff --git a/packages/cache/src/internal/shared/util.ts b/packages/cache/src/internal/shared/util.ts
new file mode 100644
index 00000000..36d2ebfd
--- /dev/null
+++ b/packages/cache/src/internal/shared/util.ts
@@ -0,0 +1,76 @@
+import {debug, setSecret} from '@actions/core'
+
+/**
+ * Masks the `sig` parameter in a URL and sets it as a secret.
+ *
+ * @param url - The URL containing the signature parameter to mask
+ * @remarks
+ * This function attempts to parse the provided URL and identify the 'sig' query parameter.
+ * If found, it registers both the raw and URL-encoded signature values as secrets using
+ * the Actions `setSecret` API, which prevents them from being displayed in logs.
+ *
+ * The function handles errors gracefully if URL parsing fails, logging them as debug messages.
+ *
+ * @example
+ * ```typescript
+ * // Mask a signature in an Azure SAS token URL
+ * maskSigUrl('https://example.blob.core.windows.net/container/file.txt?sig=abc123&se=2023-01-01');
+ * ```
+ */
+export function maskSigUrl(url: string): void {
+  if (!url) return
+  try {
+    const parsedUrl = new URL(url)
+    const signature = parsedUrl.searchParams.get('sig')
+    if (signature) {
+      setSecret(signature)
+      setSecret(encodeURIComponent(signature))
+    }
+  } catch (error) {
+    debug(
+      `Failed to parse URL: ${url} ${
+        error instanceof Error ? error.message : String(error)
+      }`
+    )
+  }
+}
+
+/**
+ * Masks sensitive information in URLs containing signature parameters.
+ * Currently supports masking 'sig' parameters in the 'signed_upload_url'
+ * and 'signed_download_url' properties of the provided object.
+ *
+ * @param body - The object should contain a signature
+ * @remarks
+ * This function extracts URLs from the object properties and calls maskSigUrl
+ * on each one to redact sensitive signature information. The function doesn't
+ * modify the original object; it only marks the signatures as secrets for
+ * logging purposes.
+ *
+ * @example
+ * ```typescript
+ * const responseBody = {
+ *   signed_upload_url: 'https://blob.core.windows.net/?sig=abc123',
+ *   signed_download_url: 'https://blob.core/windows.net/?sig=def456'
+ * };
+ * maskSecretUrls(responseBody);
+ * ```
+ */
+export function maskSecretUrls(body: Record<string, unknown> | null): void {
+  if (typeof body !== 'object' || body === null) {
+    debug('body is not an object or is null')
+    return
+  }
+  if (
+    'signed_upload_url' in body &&
+    typeof body.signed_upload_url === 'string'
+  ) {
+    maskSigUrl(body.signed_upload_url)
+  }
+  if (
+    'signed_download_url' in body &&
+    typeof body.signed_download_url === 'string'
+  ) {
+    maskSigUrl(body.signed_download_url)
+  }
+}
diff --git a/packages/core/src/command.ts b/packages/core/src/command.ts
index 2796fce9..8b3dda00 100644
--- a/packages/core/src/command.ts
+++ b/packages/core/src/command.ts
@@ -11,14 +11,37 @@ export interface CommandProperties {
 }
 
 /**
- * Commands
+ * Issues a command to the GitHub Actions runner
+ *
+ * @param command - The command name to issue
+ * @param properties - Additional properties for the command (key-value pairs)
+ * @param message - The message to include with the command
+ * @remarks
+ * This function outputs a specially formatted string to stdout that the Actions
+ * runner interprets as a command. These commands can control workflow behavior,
+ * set outputs, create annotations, mask values, and more.
  *
  * Command Format:
  *   ::name key=value,key=value::message
  *
- * Examples:
- *   ::warning::This is the message
- *   ::set-env name=MY_VAR::some value
+ * @example
+ * ```typescript
+ * // Issue a warning annotation
+ * issueCommand('warning', {}, 'This is a warning message');
+ * // Output: ::warning::This is a warning message
+ *
+ * // Set an environment variable
+ * issueCommand('set-env', { name: 'MY_VAR' }, 'some value');
+ * // Output: ::set-env name=MY_VAR::some value
+ *
+ * // Add a secret mask
+ * issueCommand('add-mask', {}, 'secretValue123');
+ * // Output: ::add-mask::secretValue123
+ * ```
+ *
+ * @internal
+ * This is an internal utility function that powers the public API functions
+ * such as setSecret, warning, error, and exportVariable.
  */
 export function issueCommand(
   command: string,
diff --git a/packages/core/src/core.ts b/packages/core/src/core.ts
index 0a141693..e9091ba2 100644
--- a/packages/core/src/core.ts
+++ b/packages/core/src/core.ts
@@ -94,7 +94,32 @@ export function exportVariable(name: string, val: any): void {
 
 /**
  * Registers a secret which will get masked from logs
- * @param secret value of the secret
+ *
+ * @param secret - Value of the secret to be masked
+ * @remarks
+ * This function instructs the Actions runner to mask the specified value in any
+ * logs produced during the workflow run. Once registered, the secret value will
+ * be replaced with asterisks (***) whenever it appears in console output, logs,
+ * or error messages.
+ *
+ * This is useful for protecting sensitive information such as:
+ * - API keys
+ * - Access tokens
+ * - Authentication credentials
+ * - URL parameters containing signatures (SAS tokens)
+ *
+ * Note that masking only affects future logs; any previous appearances of the
+ * secret in logs before calling this function will remain unmasked.
+ *
+ * @example
+ * ```typescript
+ * // Register an API token as a secret
+ * const apiToken = "abc123xyz456";
+ * setSecret(apiToken);
+ *
+ * // Now any logs containing this value will show *** instead
+ * console.log(`Using token: ${apiToken}`); // Outputs: "Using token: ***"
+ * ```
  */
 export function setSecret(secret: string): void {
   issueCommand('add-mask', {}, secret)