diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 2b2b4fa9..fed4b17f 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "0.51.0"
+  ".": "0.52.0"
 }
\ No newline at end of file
diff --git a/.stats.yml b/.stats.yml
index 6d7b67e1..fc0e4b8d 100644
--- a/.stats.yml
+++ b/.stats.yml
@@ -1,4 +1,4 @@
 configured_endpoints: 147
-openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/openai%2Fopenai-6bfe886b5ded0fe3bf37ca672698814e16e0836a093ceef65dac37ae44d1ad6b.yml
-openapi_spec_hash: 6b1344a59044318e824c8d1af96033c7
+openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/openai%2Fopenai-4432c056f89389d4d43b695cbdf44f97df8169f63bbae2c15fc079a5766ced6e.yml
+openapi_spec_hash: cbf649cc2c944fb3f77450ec752ab1e9
 config_hash: 7f49c38fa3abe9b7038ffe62262c4912
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 087f9953..97474485 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,19 @@
 # Changelog
 
+## 0.52.0 (2026-02-24)
+
+Full Changelog: [v0.51.0...v0.52.0](https://github.com/openai/openai-ruby/compare/v0.51.0...v0.52.0)
+
+### Features
+
+* **api:** remove phase from EasyInputMessage/ResponseOutputMessage, prompt_cache_key from compact ([f603ff1](https://github.com/openai/openai-ruby/commit/f603ff148798d0d47ee2caa7281dce30547cdbd6))
+
+
+### Bug Fixes
+
+* **api:** manual updates ([4f10197](https://github.com/openai/openai-ruby/commit/4f10197e93eccd7e49537716879419db09a6c477))
+* **api:** readd phase ([a78d02b](https://github.com/openai/openai-ruby/commit/a78d02b807f9282b7ba6b311c9205b9998735814))
+
 ## 0.51.0 (2026-02-24)
 
 Full Changelog: [v0.50.0...v0.51.0](https://github.com/openai/openai-ruby/compare/v0.50.0...v0.51.0)
diff --git a/Gemfile.lock b/Gemfile.lock
index da4ba63e..ba52df6b 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -11,7 +11,7 @@ GIT
 PATH
   remote: .
   specs:
-    openai (0.51.0)
+    openai (0.52.0)
       base64
       cgi
       connection_pool
diff --git a/README.md b/README.md
index 7ffb18a6..1eb33dfb 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ To use this gem, install via Bundler by adding the following to your application
 <!-- x-release-please-start-version -->
 
 ```ruby
-gem "openai", "~> 0.51.0"
+gem "openai", "~> 0.52.0"
 ```
 
 <!-- x-release-please-end -->
diff --git a/lib/openai/models/responses/easy_input_message.rb b/lib/openai/models/responses/easy_input_message.rb
index c14ce179..8994e04a 100644
--- a/lib/openai/models/responses/easy_input_message.rb
+++ b/lib/openai/models/responses/easy_input_message.rb
@@ -19,7 +19,10 @@ class EasyInputMessage < OpenAI::Internal::Type::BaseModel
         required :role, enum: -> { OpenAI::Responses::EasyInputMessage::Role }
 
         # @!attribute phase
-        #   The phase of an assistant message.
+        #   Labels an `assistant` message as intermediate commentary (`commentary`) or the
+        #   final answer (`final_answer`). For models like `gpt-5.3-codex` and beyond, when
+        #   sending follow-up requests, preserve and resend phase on all assistant messages
+        #   — dropping it can degrade performance. Not used for user messages.
         #
         #   Use `commentary` for an intermediate assistant message and `final_answer` for
         #   the final assistant message. For follow-up requests with models like
@@ -49,7 +52,7 @@ class EasyInputMessage < OpenAI::Internal::Type::BaseModel
         #
         #   @param role [Symbol, OpenAI::Models::Responses::EasyInputMessage::Role] The role of the message input. One of `user`, `assistant`, `system`, or
         #
-        #   @param phase [Symbol, OpenAI::Models::Responses::EasyInputMessage::Phase, nil] The phase of an assistant message.
+        #   @param phase [Symbol, OpenAI::Models::Responses::EasyInputMessage::Phase, nil] Labels an `assistant` message as intermediate commentary (`commentary`) or the f
         #
         #   @param type [Symbol, OpenAI::Models::Responses::EasyInputMessage::Type] The type of the message input. Always `message`.
 
@@ -87,7 +90,10 @@ module Role
           #   @return [Array<Symbol>]
         end
 
-        # The phase of an assistant message.
+        # Labels an `assistant` message as intermediate commentary (`commentary`) or the
+        # final answer (`final_answer`). For models like `gpt-5.3-codex` and beyond, when
+        # sending follow-up requests, preserve and resend phase on all assistant messages
+        # — dropping it can degrade performance. Not used for user messages.
         #
         # Use `commentary` for an intermediate assistant message and `final_answer` for
         # the final assistant message. For follow-up requests with models like
@@ -99,7 +105,6 @@ module Phase
           extend OpenAI::Internal::Type::Enum
 
           COMMENTARY = :commentary
-          FINAL_ANSWER = :final_answer
 
           # @!method self.values
           #   @return [Array<Symbol>]
diff --git a/lib/openai/models/responses/response_output_message.rb b/lib/openai/models/responses/response_output_message.rb
index 1a45e0f5..e042d0bf 100644
--- a/lib/openai/models/responses/response_output_message.rb
+++ b/lib/openai/models/responses/response_output_message.rb
@@ -37,7 +37,10 @@ class ResponseOutputMessage < OpenAI::Internal::Type::BaseModel
         required :type, const: :message
 
         # @!attribute phase
-        #   The phase of an assistant message.
+        #   Labels an `assistant` message as intermediate commentary (`commentary`) or the
+        #   final answer (`final_answer`). For models like `gpt-5.3-codex` and beyond, when
+        #   sending follow-up requests, preserve and resend phase on all assistant messages
+        #   — dropping it can degrade performance. Not used for user messages.
         #
         #   Use `commentary` for an intermediate assistant message and `final_answer` for
         #   the final assistant message. For follow-up requests with models like
@@ -59,7 +62,7 @@ class ResponseOutputMessage < OpenAI::Internal::Type::BaseModel
         #
         #   @param status [Symbol, OpenAI::Models::Responses::ResponseOutputMessage::Status] The status of the message input. One of `in_progress`, `completed`, or
         #
-        #   @param phase [Symbol, OpenAI::Models::Responses::ResponseOutputMessage::Phase, nil] The phase of an assistant message.
+        #   @param phase [Symbol, OpenAI::Models::Responses::ResponseOutputMessage::Phase, nil] Labels an `assistant` message as intermediate commentary (`commentary`) or the f
         #
         #   @param role [Symbol, :assistant] The role of the output message. Always `assistant`.
         #
@@ -96,7 +99,10 @@ module Status
           #   @return [Array<Symbol>]
         end
 
-        # The phase of an assistant message.
+        # Labels an `assistant` message as intermediate commentary (`commentary`) or the
+        # final answer (`final_answer`). For models like `gpt-5.3-codex` and beyond, when
+        # sending follow-up requests, preserve and resend phase on all assistant messages
+        # — dropping it can degrade performance. Not used for user messages.
         #
         # Use `commentary` for an intermediate assistant message and `final_answer` for
         # the final assistant message. For follow-up requests with models like
@@ -108,7 +114,6 @@ module Phase
           extend OpenAI::Internal::Type::Enum
 
           COMMENTARY = :commentary
-          FINAL_ANSWER = :final_answer
 
           # @!method self.values
           #   @return [Array<Symbol>]
diff --git a/lib/openai/version.rb b/lib/openai/version.rb
index 2e0e97ee..0bbb0eab 100644
--- a/lib/openai/version.rb
+++ b/lib/openai/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module OpenAI
-  VERSION = "0.51.0"
+  VERSION = "0.52.0"
 end
diff --git a/rbi/openai/models/responses/easy_input_message.rbi b/rbi/openai/models/responses/easy_input_message.rbi
index b2c81c0a..d887196f 100644
--- a/rbi/openai/models/responses/easy_input_message.rbi
+++ b/rbi/openai/models/responses/easy_input_message.rbi
@@ -22,7 +22,10 @@ module OpenAI
         sig { returns(OpenAI::Responses::EasyInputMessage::Role::OrSymbol) }
         attr_accessor :role
 
-        # The phase of an assistant message.
+        # Labels an `assistant` message as intermediate commentary (`commentary`) or the
+        # final answer (`final_answer`). For models like `gpt-5.3-codex` and beyond, when
+        # sending follow-up requests, preserve and resend phase on all assistant messages
+        # — dropping it can degrade performance. Not used for user messages.
         #
         # Use `commentary` for an intermediate assistant message and `final_answer` for
         # the final assistant message. For follow-up requests with models like
@@ -69,7 +72,10 @@ module OpenAI
           # The role of the message input. One of `user`, `assistant`, `system`, or
           # `developer`.
           role:,
-          # The phase of an assistant message.
+          # Labels an `assistant` message as intermediate commentary (`commentary`) or the
+          # final answer (`final_answer`). For models like `gpt-5.3-codex` and beyond, when
+          # sending follow-up requests, preserve and resend phase on all assistant messages
+          # — dropping it can degrade performance. Not used for user messages.
           #
           # Use `commentary` for an intermediate assistant message and `final_answer` for
           # the final assistant message. For follow-up requests with models like
@@ -158,7 +164,10 @@ module OpenAI
           end
         end
 
-        # The phase of an assistant message.
+        # Labels an `assistant` message as intermediate commentary (`commentary`) or the
+        # final answer (`final_answer`). For models like `gpt-5.3-codex` and beyond, when
+        # sending follow-up requests, preserve and resend phase on all assistant messages
+        # — dropping it can degrade performance. Not used for user messages.
         #
         # Use `commentary` for an intermediate assistant message and `final_answer` for
         # the final assistant message. For follow-up requests with models like
@@ -178,11 +187,6 @@ module OpenAI
               :commentary,
               OpenAI::Responses::EasyInputMessage::Phase::TaggedSymbol
             )
-          FINAL_ANSWER =
-            T.let(
-              :final_answer,
-              OpenAI::Responses::EasyInputMessage::Phase::TaggedSymbol
-            )
 
           sig do
             override.returns(
diff --git a/rbi/openai/models/responses/response_output_message.rbi b/rbi/openai/models/responses/response_output_message.rbi
index e09b7ea3..760ea24f 100644
--- a/rbi/openai/models/responses/response_output_message.rbi
+++ b/rbi/openai/models/responses/response_output_message.rbi
@@ -44,7 +44,10 @@ module OpenAI
         sig { returns(Symbol) }
         attr_accessor :type
 
-        # The phase of an assistant message.
+        # Labels an `assistant` message as intermediate commentary (`commentary`) or the
+        # final answer (`final_answer`). For models like `gpt-5.3-codex` and beyond, when
+        # sending follow-up requests, preserve and resend phase on all assistant messages
+        # — dropping it can degrade performance. Not used for user messages.
         #
         # Use `commentary` for an intermediate assistant message and `final_answer` for
         # the final assistant message. For follow-up requests with models like
@@ -85,7 +88,10 @@ module OpenAI
           # The status of the message input. One of `in_progress`, `completed`, or
           # `incomplete`. Populated when input items are returned via API.
           status:,
-          # The phase of an assistant message.
+          # Labels an `assistant` message as intermediate commentary (`commentary`) or the
+          # final answer (`final_answer`). For models like `gpt-5.3-codex` and beyond, when
+          # sending follow-up requests, preserve and resend phase on all assistant messages
+          # — dropping it can degrade performance. Not used for user messages.
           #
           # Use `commentary` for an intermediate assistant message and `final_answer` for
           # the final assistant message. For follow-up requests with models like
@@ -185,7 +191,10 @@ module OpenAI
           end
         end
 
-        # The phase of an assistant message.
+        # Labels an `assistant` message as intermediate commentary (`commentary`) or the
+        # final answer (`final_answer`). For models like `gpt-5.3-codex` and beyond, when
+        # sending follow-up requests, preserve and resend phase on all assistant messages
+        # — dropping it can degrade performance. Not used for user messages.
         #
         # Use `commentary` for an intermediate assistant message and `final_answer` for
         # the final assistant message. For follow-up requests with models like
@@ -205,11 +214,6 @@ module OpenAI
               :commentary,
               OpenAI::Responses::ResponseOutputMessage::Phase::TaggedSymbol
             )
-          FINAL_ANSWER =
-            T.let(
-              :final_answer,
-              OpenAI::Responses::ResponseOutputMessage::Phase::TaggedSymbol
-            )
 
           sig do
             override.returns(
diff --git a/sig/openai/models/responses/easy_input_message.rbs b/sig/openai/models/responses/easy_input_message.rbs
index 587764bb..d69a671c 100644
--- a/sig/openai/models/responses/easy_input_message.rbs
+++ b/sig/openai/models/responses/easy_input_message.rbs
@@ -59,13 +59,12 @@ module OpenAI
           def self?.values: -> ::Array[OpenAI::Models::Responses::EasyInputMessage::role]
         end
 
-        type phase = :commentary | :final_answer
+        type phase = :commentary
 
         module Phase
           extend OpenAI::Internal::Type::Enum
 
           COMMENTARY: :commentary
-          FINAL_ANSWER: :final_answer
 
           def self?.values: -> ::Array[OpenAI::Models::Responses::EasyInputMessage::phase]
         end
diff --git a/sig/openai/models/responses/response_output_message.rbs b/sig/openai/models/responses/response_output_message.rbs
index 0a0097a7..a7fbe417 100644
--- a/sig/openai/models/responses/response_output_message.rbs
+++ b/sig/openai/models/responses/response_output_message.rbs
@@ -64,13 +64,12 @@ module OpenAI
           def self?.values: -> ::Array[OpenAI::Models::Responses::ResponseOutputMessage::status]
         end
 
-        type phase = :commentary | :final_answer
+        type phase = :commentary
 
         module Phase
           extend OpenAI::Internal::Type::Enum
 
           COMMENTARY: :commentary
-          FINAL_ANSWER: :final_answer
 
           def self?.values: -> ::Array[OpenAI::Models::Responses::ResponseOutputMessage::phase]
         end