diff --git a/packages/cache/README.md b/packages/cache/README.md
index 55185032..0f743848 100644
--- a/packages/cache/README.md
+++ b/packages/cache/README.md
@@ -6,6 +6,20 @@ See ["Caching dependencies to speed up workflows"](https://docs.github.com/en/ac
 
 Note that GitHub will remove any cache entries that have not been accessed in over 7 days. There is no limit on the number of caches you can store, but the total size of all caches in a repository is limited to 10 GB. If you exceed this limit, GitHub will save your cache but will begin evicting caches until the total size is less than 10 GB.
 
+## ⚠️ Important changes
+
+The cache backend service has been rewritten from the ground up for improved performance and reliability. The [@actions/cache](https://github.com/actions/toolkit/tree/main/packages/cache) package now integrates with the new cache service (v2) APIs.
+
+The new service will gradually roll out as of **February 1st, 2025**. The legacy service will also be sunset on the same date. Changes in this release are **fully backward compatible**.
+
+**All previous versions of this package will be deprecated**. We recommend upgrading to version `4.0.0` as soon as possible before **February 1st, 2025.**
+
+If you do not upgrade, all workflow runs using any of the deprecated [@actions/cache](https://github.com/actions/toolkit/tree/main/packages/cache) packages will fail.
+
+Upgrading to the recommended version should not break or require any changes to your workflows beyond updating your `package.json` to version `4.0.0`.
+
+Read more about the change & access the migration guide: [reference to the announcement](https://github.com/actions/toolkit/discussions/1890).
+
 ## Usage
 
 This package is used by the v2+ versions of our first party cache action. You can find an example implementation in the cache repo [here](https://github.com/actions/cache).
@@ -47,5 +61,3 @@ const cacheKey = await cache.restoreCache(paths, key, restoreKeys)
 A cache gets downloaded in multiple segments of fixed sizes (now `128MB` to fail-fast, previously `1GB` for a `32-bit` runner and `2GB` for a `64-bit` runner were used). Sometimes, a segment download gets stuck which causes the workflow job to be stuck forever and fail. Version `v3.0.4` of cache package introduces a segment download timeout. The segment download timeout will allow the segment download to get aborted and hence allow the job to proceed with a cache miss.
 
 Default value of this timeout is 10 minutes (starting `v3.2.1` and higher, previously 60 minutes in versions between `v.3.0.4` and `v3.2.0`, both included) and can be customized by specifying an [environment variable](https://docs.github.com/en/actions/learn-github-actions/environment-variables) named `SEGMENT_DOWNLOAD_TIMEOUT_MINS` with timeout value in minutes.
-
-
diff --git a/packages/cache/RELEASES.md b/packages/cache/RELEASES.md
index 85415952..8355e977 100644
--- a/packages/cache/RELEASES.md
+++ b/packages/cache/RELEASES.md
@@ -1,6 +1,29 @@
 # @actions/cache Releases
 
+### 4.0.0
+
+#### Important changes
+
+The cache backend service has been rewritten from the ground up for improved performance and reliability. The [@actions/cache](https://github.com/actions/toolkit/tree/main/packages/cache) package now integrates with the new cache service (v2) APIs.
+
+The new service will gradually roll out as of **February 1st, 2025**. The legacy service will also be sunset on the same date. Changes in this release are **fully backward compatible**.
+
+**All previous versions of this package will be deprecated**. We recommend upgrading to version `4.0.0` as soon as possible before **February 1st, 2025.**
+
+If you do not upgrade, all workflow runs using any of the deprecated [@actions/cache](https://github.com/actions/toolkit/tree/main/packages/cache) packages will fail.
+
+Upgrading to the recommended version should not break or require any changes to your workflows beyond updating your `package.json` to version `4.0.0`.
+
+Read more about the change & access the migration guide: [reference to the announcement](https://github.com/actions/toolkit/discussions/1890).
+
+#### Minor changes
+
+- Update `@actions/core` to `1.11.0`
+- Update `semver` `6.3.1`
+- Add `twirp-ts` `2.5.0` to dependencies
+
 ### 3.3.0
+
 - Update `@actions/core` to `1.11.1`
 - Remove dependency on `uuid` package [#1824](https://github.com/actions/toolkit/pull/1824), [#1842](https://github.com/actions/toolkit/pull/1842)
 
diff --git a/packages/cache/package-lock.json b/packages/cache/package-lock.json
index beb23a68..132391fb 100644
--- a/packages/cache/package-lock.json
+++ b/packages/cache/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@actions/cache",
-  "version": "3.3.0",
+  "version": "4.0.0",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "@actions/cache",
-      "version": "3.3.0",
+      "version": "4.0.0",
       "license": "MIT",
       "dependencies": {
         "@actions/core": "^1.11.1",
diff --git a/packages/cache/package.json b/packages/cache/package.json
index e5332a92..b03f4221 100644
--- a/packages/cache/package.json
+++ b/packages/cache/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@actions/cache",
-  "version": "3.3.0",
+  "version": "4.0.0",
   "preview": true,
   "description": "Actions cache lib",
   "keywords": [