diff --git a/.github/workflows/swift.yml b/.github/workflows/swift.yml
index dc913225..a56ea887 100644
--- a/.github/workflows/swift.yml
+++ b/.github/workflows/swift.yml
@@ -17,7 +17,7 @@ on:
description: release
env:
- VERSION: 3.10.4
+ VERSION: 4.0.0
jobs:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index b82b4130..9387f9d4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,62 @@
# Optimizely Swift SDK Changelog
+## 4.0.0
+Jan 18, 2024
+
+### New Features
+
+The 4.0.0 release introduces a new primary feature, [Advanced Audience Targeting]( https://docs.developers.optimizely.com/feature-experimentation/docs/optimizely-data-platform-advanced-audience-targeting) enabled through integration with [Optimizely Data Platform (ODP)](https://docs.developers.optimizely.com/optimizely-data-platform/docs) ([#455](https://github.com/optimizely/swift-sdk/pull/455), [#470](https://github.com/optimizely/swift-sdk/pull/470), [#471](https://github.com/optimizely/swift-sdk/pull/471), [#477](https://github.com/optimizely/swift-sdk/pull/477),[#512](https://github.com/optimizely/swift-sdk/pull/512)).
+
+You can use ODP, a high-performance [Customer Data Platform (CDP)]( https://www.optimizely.com/optimization-glossary/customer-data-platform/), to easily create complex real-time segments (RTS) using first-party and 50+ third-party data sources out of the box. You can create custom schemas that support the user attributes important for your business, and stitch together user behavior done on different devices to better understand and target your customers for personalized user experiences. ODP can be used as a single source of truth for these segments in any Optimizely or 3rd party tool.
+
+With ODP accounts integrated into Optimizely projects, you can build audiences using segments pre-defined in ODP. The SDK will fetch the segments for given users and make decisions using the segments. For access to ODP audience targeting in your Feature Experimentation account, please contact your Customer Success Manager.
+
+This version includes the following changes:
+
+* New API added to `OptimizelyUserContext`:
+
+ - `fetchQualifiedSegments()`: this API will retrieve user segments from the ODP server. The fetched segments will be used for audience evaluation. The fetched data will be stored in the local cache to avoid repeated network delays.
+
+ - When an `OptimizelyUserContext` is created, the SDK will automatically send an identify request to the ODP server to facilitate observing user activities.
+
+* New APIs added to `OptimizelyClient`:
+
+ - `sendOdpEvent()`: customers can build/send arbitrary ODP events that will bind user identifiers and data to user profiles in ODP.
+
+ - `createUserContext()` with anonymous user IDs: user-contexts can be created without a userId. The SDK will create and use a persistent `VUID` specific to a device when userId is not provided.
+
+For details, refer to our documentation pages:
+
+* [Advanced Audience Targeting](https://docs.developers.optimizely.com/feature-experimentation/docs/optimizely-data-platform-advanced-audience-targeting)
+
+* [Client SDK Support](https://docs.developers.optimizely.com/feature-experimentation/v1.0/docs/advanced-audience-targeting-for-client-side-sdks)
+
+* [Initialize Swift SDK](https://docs.developers.optimizely.com/feature-experimentation/docs/initialize-sdk-swift)
+
+* [OptimizelyUserContext Swift SDK](https://docs.developers.optimizely.com/feature-experimentation/docs/optimizelyusercontext-swift)
+
+* [Advanced Audience Targeting segment qualification methods](https://docs.developers.optimizely.com/feature-experimentation/docs/advanced-audience-targeting-segment-qualification-methods-swift)
+
+* [Send Optimizely Data Platform data using Advanced Audience Targeting](https://docs.developers.optimizely.com/feature-experimentation/docs/send-odp-data-using-advanced-audience-targeting-swift)
+
+### Breaking Changes
+
+* `ODPManager` in the SDK is enabled by default. Unless an ODP account is integrated into the Optimizely projects, most `ODPManager` functions will be ignored. If needed, `ODPManager` can be disabled when `OptimizelyClient` is instantiated.
+
+### Bug Fixes
+* Adds a check to only save valid datafile in cache. ([#514](https://github.com/optimizely/swift-sdk/pull/514))
+* Remove redundant post request body in upload task. ([#521](https://github.com/optimizely/swift-sdk/pull/521/)).
+* Privacy manifest file value for required reason API fixed. ([#541](https://github.com/optimizely/swift-sdk/pull/541))
+* Add coccoapods support for privacy manifest. ([#542](https://github.com/optimizely/swift-sdk/pull/542))
+* Add SPM support added to process privacy manifest. ([#544](https://github.com/optimizely/swift-sdk/pull/544))
+
+### Functionality Enhancement
+* Adds support to override sdkName and sdkVersion for events. ([#512](https://github.com/optimizely/swift-sdk/pull/512))
+* Swift async-await support. ([#513](https://github.com/optimizely/swift-sdk/pull/513))
+* Update Github Issue Templates. ([#516](https://github.com/optimizely/swift-sdk/pull/516))
+* Handle duplicate keys in experiment ([#523](https://github.com/optimizely/swift-sdk/pull/523/)).
+* Add privacy manifest file ([#522](https://github.com/optimizely/swift-sdk/pull/522/)).
+
## 3.10.4
December 8, 2023
diff --git a/README.md b/README.md
index 2d387b05..aa8cc378 100644
--- a/README.md
+++ b/README.md
@@ -39,7 +39,7 @@ If you have a name conflict with other swift packages when you add the Optimizel
#### CocoaPods
1. Add the following lines to the _Podfile_:
```use_frameworks!```
-```pod 'OptimizelySwiftSDK', '~> 3.10.4'```
+```pod 'OptimizelySwiftSDK', '~> 4.0.0'```
2. Run the following command: ``` pod install ```
@@ -47,7 +47,7 @@ If you have a name conflict with other swift packages when you add the Optimizel
Further installation instructions for Cocoapods: https://guides.cocoapods.org/using/getting-started.html
#### Carthage
-1. Add the following lines to the _Cartfile_:```github "optimizely/swift-sdk" ~> 3.10.4```
+1. Add the following lines to the _Cartfile_:```github "optimizely/swift-sdk" ~> 4.0.0```
2. Run the following command:```carthage update```