diff --git a/.castiron.stats.yml b/.castiron.stats.yml
index 265aee353..229d4f598 100644
--- a/.castiron.stats.yml
+++ b/.castiron.stats.yml
@@ -1,8 +1,8 @@
 schema_version: 1
-generation_id: e4e0ce05-9226-4d09-bb9e-e6268c8e7878
-openapi_spec_hash: b2c62b342b04685226037c980f2b5a7a
-openapi_transformed_spec_hash: ba44bf31326f01a1d886b7510dd9da8a
-config_hash: 4fbbbcf377bcc17646cccb9fcfbac14a
-codegen_sha: eec7edf94936ec5f7c0f9ec8cfde8cbb63c6c3f2
-codegen_hash: 87258f04a796ec9ab2c33d4969d476d2775efb5660ed4111f162262a25aafa02
-public_codegen_sha: fd15fb6f3ba079f02c5269a8f4c881c932254466
+generation_id: a83d988d-33da-49ce-a212-bb4d1220e69d
+openapi_spec_hash: 32e9f9c8096eae027754def9afb89dc0
+openapi_transformed_spec_hash: a5861d7f7b67f6845c9499fdec7324a5
+config_hash: 5c00fe18ea913ed0186f9894adc02a70
+codegen_sha: 4785a2639a879fe7df310893e4d7d1e7284d2b29
+codegen_hash: ee7ca84550f48649fac01391ae5ae621791dcbe4ae5a69b94adaafd97087d79e
+public_codegen_sha: bdff21b1700b4868f153015258d805695ce62a68
diff --git a/api_reference/openapi.transformed.yml b/api_reference/openapi.transformed.yml
index 164fe8c28..556cdd2d9 100644
--- a/api_reference/openapi.transformed.yml
+++ b/api_reference/openapi.transformed.yml
@@ -37968,7 +37968,6 @@ components:
           - incomplete
       required:
       - type
-      - call_id
       - output
     FunctionToolCallOutputResource:
       allOf:
@@ -63939,10 +63938,12 @@ components:
             example: fc_123
           - type: 'null'
         call_id:
-          type: string
-          maxLength: 64
-          minLength: 1
-          description: The unique ID of the function tool call generated by the model.
+          anyOf:
+          - type: string
+            maxLength: 64
+            minLength: 1
+            description: The unique ID of the function tool call generated by the model.
+          - type: 'null'
         type:
           type: string
           enum:
@@ -63994,7 +63995,6 @@ components:
       type: object
       required:
       - type
-      - call_id
       - output
       title: Function tool call output
       description: The output of a function tool call.
@@ -71251,10 +71251,12 @@ components:
             example: fc_123
           - type: 'null'
         call_id:
-          type: string
-          maxLength: 64
-          minLength: 1
-          description: The unique ID of the function tool call generated by the model.
+          anyOf:
+          - type: string
+            maxLength: 64
+            minLength: 1
+            description: The unique ID of the function tool call generated by the model.
+          - type: 'null'
         type:
           type: string
           enum:
@@ -71306,7 +71308,6 @@ components:
       type: object
       required:
       - type
-      - call_id
       - output
       title: Function tool call output
       description: The output of a function tool call.
@@ -73658,7 +73659,6 @@ components:
           - incomplete
       required:
       - type
-      - call_id
       - output
     BetaFunctionToolCallResource:
       allOf:
diff --git a/lib/openai/models/beta/beta_response_function_tool_call_output_item.rb b/lib/openai/models/beta/beta_response_function_tool_call_output_item.rb
index 6c0104803..b57172e27 100644
--- a/lib/openai/models/beta/beta_response_function_tool_call_output_item.rb
+++ b/lib/openai/models/beta/beta_response_function_tool_call_output_item.rb
@@ -10,12 +10,6 @@ class BetaResponseFunctionToolCallOutputItem < OpenAI::Internal::Type::BaseModel
         #   @return [String]
         required :id, String
 
-        # @!attribute call_id
-        #   The unique ID of the function tool call generated by the model.
-        #
-        #   @return [String]
-        required :call_id, String
-
         # @!attribute output
         #   The output from the function call generated by your code. Can be a string or an
         #   list of output content.
@@ -42,6 +36,12 @@ class BetaResponseFunctionToolCallOutputItem < OpenAI::Internal::Type::BaseModel
         #   @return [OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem::Agent, nil]
         optional :agent, -> { OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Agent }, nil?: true
 
+        # @!attribute call_id
+        #   The unique ID of the function tool call generated by the model.
+        #
+        #   @return [String, nil]
+        optional :call_id, String
+
         # @!attribute caller_
         #   The execution context that produced this tool call.
         #
@@ -71,20 +71,20 @@ class BetaResponseFunctionToolCallOutputItem < OpenAI::Internal::Type::BaseModel
         #   @return [String, nil]
         optional :namespace, String
 
-        # @!method initialize(id:, call_id:, output:, status:, agent: nil, caller_: nil, created_by: nil, name: nil, namespace: nil, type: :function_call_output)
+        # @!method initialize(id:, output:, status:, agent: nil, call_id: nil, caller_: nil, created_by: nil, name: nil, namespace: nil, type: :function_call_output)
         #   Some parameter documentations has been truncated, see
         #   {OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem} for more details.
         #
         #   @param id [String] The unique ID of the function call tool output.
         #
-        #   @param call_id [String] The unique ID of the function tool call generated by the model.
-        #
         #   @param output [String, Array<OpenAI::Models::Beta::BetaResponseInputText, OpenAI::Models::Beta::BetaResponseInputImage, OpenAI::Models::Beta::BetaResponseInputFile>] The output from the function call generated by your code.
         #
         #   @param status [Symbol, OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem::Status] The status of the item. One of `in_progress`, `completed`, or
         #
         #   @param agent [OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem::Agent, nil] The agent that produced this item.
         #
+        #   @param call_id [String] The unique ID of the function tool call generated by the model.
+        #
         #   @param caller_ [OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem::Caller::Direct, OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem::Caller::Program, nil] The execution context that produced this tool call.
         #
         #   @param created_by [String] The identifier of the actor that created the item.
diff --git a/lib/openai/models/beta/beta_response_input_item.rb b/lib/openai/models/beta/beta_response_input_item.rb
index d5ba8bab5..9a404a21a 100644
--- a/lib/openai/models/beta/beta_response_input_item.rb
+++ b/lib/openai/models/beta/beta_response_input_item.rb
@@ -371,12 +371,6 @@ module Status
         end
 
         class FunctionCallOutput < OpenAI::Internal::Type::BaseModel
-          # @!attribute call_id
-          #   The unique ID of the function tool call generated by the model.
-          #
-          #   @return [String]
-          required :call_id, String
-
           # @!attribute output
           #   Text, image, or file output of the function tool call.
           #
@@ -402,6 +396,12 @@ class FunctionCallOutput < OpenAI::Internal::Type::BaseModel
           #   @return [OpenAI::Models::Beta::BetaResponseInputItem::FunctionCallOutput::Agent, nil]
           optional :agent, -> { OpenAI::Beta::BetaResponseInputItem::FunctionCallOutput::Agent }, nil?: true
 
+          # @!attribute call_id
+          #   The unique ID of the function tool call generated by the model.
+          #
+          #   @return [String, nil]
+          optional :call_id, String, nil?: true
+
           # @!attribute caller_
           #   The execution context that produced this tool call.
           #
@@ -438,21 +438,21 @@ class FunctionCallOutput < OpenAI::Internal::Type::BaseModel
             nil?: true
           )
 
-          # @!method initialize(call_id:, output:, id: nil, agent: nil, caller_: nil, name: nil, namespace: nil, status: nil, type: :function_call_output)
+          # @!method initialize(output:, id: nil, agent: nil, call_id: nil, caller_: nil, name: nil, namespace: nil, status: nil, type: :function_call_output)
           #   Some parameter documentations has been truncated, see
           #   {OpenAI::Models::Beta::BetaResponseInputItem::FunctionCallOutput} for more
           #   details.
           #
           #   The output of a function tool call.
           #
-          #   @param call_id [String] The unique ID of the function tool call generated by the model.
-          #
           #   @param output [String, Array<OpenAI::Models::Beta::BetaResponseInputTextContent, OpenAI::Models::Beta::BetaResponseInputImageContent, OpenAI::Models::Beta::BetaResponseInputFileContent>] Text, image, or file output of the function tool call.
           #
           #   @param id [String, nil] The unique ID of the function tool call output. Populated when this item is retu
           #
           #   @param agent [OpenAI::Models::Beta::BetaResponseInputItem::FunctionCallOutput::Agent, nil] The agent that produced this item.
           #
+          #   @param call_id [String, nil] The unique ID of the function tool call generated by the model.
+          #
           #   @param caller_ [OpenAI::Models::Beta::BetaResponseInputItem::FunctionCallOutput::Caller::Direct, OpenAI::Models::Beta::BetaResponseInputItem::FunctionCallOutput::Caller::Program, nil] The execution context that produced this tool call.
           #
           #   @param name [String, nil] The name of the tool that produced the output.
diff --git a/lib/openai/models/responses/response_function_tool_call_output_item.rb b/lib/openai/models/responses/response_function_tool_call_output_item.rb
index 106a313f8..48fa67e6f 100644
--- a/lib/openai/models/responses/response_function_tool_call_output_item.rb
+++ b/lib/openai/models/responses/response_function_tool_call_output_item.rb
@@ -10,12 +10,6 @@ class ResponseFunctionToolCallOutputItem < OpenAI::Internal::Type::BaseModel
         #   @return [String]
         required :id, String
 
-        # @!attribute call_id
-        #   The unique ID of the function tool call generated by the model.
-        #
-        #   @return [String]
-        required :call_id, String
-
         # @!attribute output
         #   The output from the function call generated by your code. Can be a string or an
         #   list of output content.
@@ -36,6 +30,12 @@ class ResponseFunctionToolCallOutputItem < OpenAI::Internal::Type::BaseModel
         #   @return [Symbol, :function_call_output]
         required :type, const: :function_call_output
 
+        # @!attribute call_id
+        #   The unique ID of the function tool call generated by the model.
+        #
+        #   @return [String, nil]
+        optional :call_id, String
+
         # @!attribute caller_
         #   The execution context that produced this tool call.
         #
@@ -65,19 +65,19 @@ class ResponseFunctionToolCallOutputItem < OpenAI::Internal::Type::BaseModel
         #   @return [String, nil]
         optional :namespace, String
 
-        # @!method initialize(id:, call_id:, output:, status:, caller_: nil, created_by: nil, name: nil, namespace: nil, type: :function_call_output)
+        # @!method initialize(id:, output:, status:, call_id: nil, caller_: nil, created_by: nil, name: nil, namespace: nil, type: :function_call_output)
         #   Some parameter documentations has been truncated, see
         #   {OpenAI::Models::Responses::ResponseFunctionToolCallOutputItem} for more
         #   details.
         #
         #   @param id [String] The unique ID of the function call tool output.
         #
-        #   @param call_id [String] The unique ID of the function tool call generated by the model.
-        #
         #   @param output [String, Array<OpenAI::Models::Responses::ResponseInputText, OpenAI::Models::Responses::ResponseInputImage, OpenAI::Models::Responses::ResponseInputFile>] The output from the function call generated by your code.
         #
         #   @param status [Symbol, OpenAI::Models::Responses::ResponseFunctionToolCallOutputItem::Status] The status of the item. One of `in_progress`, `completed`, or
         #
+        #   @param call_id [String] The unique ID of the function tool call generated by the model.
+        #
         #   @param caller_ [OpenAI::Models::Responses::ResponseFunctionToolCallOutputItem::Caller::Direct, OpenAI::Models::Responses::ResponseFunctionToolCallOutputItem::Caller::Program, nil] The execution context that produced this tool call.
         #
         #   @param created_by [String] The identifier of the actor that created the item.
diff --git a/lib/openai/models/responses/response_input_item.rb b/lib/openai/models/responses/response_input_item.rb
index e50673195..06befa3d2 100644
--- a/lib/openai/models/responses/response_input_item.rb
+++ b/lib/openai/models/responses/response_input_item.rb
@@ -318,12 +318,6 @@ module Status
         end
 
         class FunctionCallOutput < OpenAI::Internal::Type::BaseModel
-          # @!attribute call_id
-          #   The unique ID of the function tool call generated by the model.
-          #
-          #   @return [String]
-          required :call_id, String
-
           # @!attribute output
           #   Text, image, or file output of the function tool call.
           #
@@ -343,6 +337,12 @@ class FunctionCallOutput < OpenAI::Internal::Type::BaseModel
           #   @return [String, nil]
           optional :id, String, nil?: true
 
+          # @!attribute call_id
+          #   The unique ID of the function tool call generated by the model.
+          #
+          #   @return [String, nil]
+          optional :call_id, String, nil?: true
+
           # @!attribute caller_
           #   The execution context that produced this tool call.
           #
@@ -377,19 +377,19 @@ class FunctionCallOutput < OpenAI::Internal::Type::BaseModel
             nil?: true
           )
 
-          # @!method initialize(call_id:, output:, id: nil, caller_: nil, name: nil, namespace: nil, status: nil, type: :function_call_output)
+          # @!method initialize(output:, id: nil, call_id: nil, caller_: nil, name: nil, namespace: nil, status: nil, type: :function_call_output)
           #   Some parameter documentations has been truncated, see
           #   {OpenAI::Models::Responses::ResponseInputItem::FunctionCallOutput} for more
           #   details.
           #
           #   The output of a function tool call.
           #
-          #   @param call_id [String] The unique ID of the function tool call generated by the model.
-          #
           #   @param output [String, Array<OpenAI::Models::Responses::ResponseInputTextContent, OpenAI::Models::Responses::ResponseInputImageContent, OpenAI::Models::Responses::ResponseInputFileContent>] Text, image, or file output of the function tool call.
           #
           #   @param id [String, nil] The unique ID of the function tool call output. Populated when this item is retu
           #
+          #   @param call_id [String, nil] The unique ID of the function tool call generated by the model.
+          #
           #   @param caller_ [OpenAI::Models::Responses::ResponseInputItem::FunctionCallOutput::Caller::Direct, OpenAI::Models::Responses::ResponseInputItem::FunctionCallOutput::Caller::Program, nil] The execution context that produced this tool call.
           #
           #   @param name [String, nil] The name of the tool that produced the output.
diff --git a/rbi/openai/models/beta/beta_response_function_tool_call_output_item.rbi b/rbi/openai/models/beta/beta_response_function_tool_call_output_item.rbi
index 777c7d7d8..c53dabe2e 100644
--- a/rbi/openai/models/beta/beta_response_function_tool_call_output_item.rbi
+++ b/rbi/openai/models/beta/beta_response_function_tool_call_output_item.rbi
@@ -20,10 +20,6 @@ module OpenAI
         sig { returns(String) }
         attr_accessor :id
 
-        # The unique ID of the function tool call generated by the model.
-        sig { returns(String) }
-        attr_accessor :call_id
-
         # The output from the function call generated by your code. Can be a string or an
         # list of output content.
         sig { returns(OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Output::Variants) }
@@ -45,6 +41,13 @@ module OpenAI
         sig { params(agent: T.nilable(OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Agent::OrHash)).void }
         attr_writer :agent
 
+        # The unique ID of the function tool call generated by the model.
+        sig { returns(T.nilable(String)) }
+        attr_reader :call_id
+
+        sig { params(call_id: String).void }
+        attr_writer :call_id
+
         # The execution context that produced this tool call.
         sig { returns(T.nilable(OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Caller::Variants)) }
         attr_accessor :caller_
@@ -75,14 +78,14 @@ module OpenAI
 
             id: String,
 
-            call_id: String,
-
             output: OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Output::Variants,
 
             status: OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Status::OrSymbol,
 
             agent: T.nilable(OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Agent::OrHash),
 
+            call_id: String,
+
             caller_: T.nilable(
               T.any(
                 OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Caller::Direct::OrHash,
@@ -105,9 +108,6 @@ module OpenAI
           # The unique ID of the function call tool output.
           id:,
 
-          # The unique ID of the function tool call generated by the model.
-          call_id:,
-
           # The output from the function call generated by your code. Can be a string or an
           # list of output content.
           output:,
@@ -119,6 +119,9 @@ module OpenAI
           # The agent that produced this item.
           agent: nil,
 
+          # The unique ID of the function tool call generated by the model.
+          call_id: nil,
+
           # The execution context that produced this tool call.
           caller_: nil,
 
@@ -141,11 +144,11 @@ module OpenAI
           override.returns(
             {
               id: String,
-              call_id: String,
               output: OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Output::Variants,
               status: OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Status::TaggedSymbol,
               type: Symbol,
               agent: T.nilable(OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Agent),
+              call_id: String,
               caller_: T.nilable(OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Caller::Variants),
               created_by: String,
               name: String,
diff --git a/rbi/openai/models/beta/beta_response_input_item.rbi b/rbi/openai/models/beta/beta_response_input_item.rbi
index 320108dc5..3e8d72bab 100644
--- a/rbi/openai/models/beta/beta_response_input_item.rbi
+++ b/rbi/openai/models/beta/beta_response_input_item.rbi
@@ -502,10 +502,6 @@ module OpenAI
             )
           end
 
-          # The unique ID of the function tool call generated by the model.
-          sig { returns(String) }
-          attr_accessor :call_id
-
           # Text, image, or file output of the function tool call.
           sig { returns(OpenAI::Beta::BetaResponseInputItem::FunctionCallOutput::Output::Variants) }
           attr_accessor :output
@@ -526,6 +522,10 @@ module OpenAI
           sig { params(agent: T.nilable(OpenAI::Beta::BetaResponseInputItem::FunctionCallOutput::Agent::OrHash)).void }
           attr_writer :agent
 
+          # The unique ID of the function tool call generated by the model.
+          sig { returns(T.nilable(String)) }
+          attr_accessor :call_id
+
           # The execution context that produced this tool call.
           sig {
             returns(
@@ -556,14 +556,14 @@ module OpenAI
           sig do
             params(
 
-              call_id: String,
-
               output: OpenAI::Beta::BetaResponseInputItem::FunctionCallOutput::Output::Variants,
 
               id: T.nilable(String),
 
               agent: T.nilable(OpenAI::Beta::BetaResponseInputItem::FunctionCallOutput::Agent::OrHash),
 
+              call_id: T.nilable(String),
+
               caller_: T.nilable(
                 T.any(
                   OpenAI::Beta::BetaResponseInputItem::FunctionCallOutput::Caller::Direct::OrHash,
@@ -583,9 +583,6 @@ module OpenAI
           end
           def self.new(
 
-            # The unique ID of the function tool call generated by the model.
-            call_id:,
-
             # Text, image, or file output of the function tool call.
             output:,
 
@@ -596,6 +593,9 @@ module OpenAI
             # The agent that produced this item.
             agent: nil,
 
+            # The unique ID of the function tool call generated by the model.
+            call_id: nil,
+
             # The execution context that produced this tool call.
             caller_: nil,
 
@@ -618,11 +618,11 @@ module OpenAI
           sig do
             override.returns(
               {
-                call_id: String,
                 output: OpenAI::Beta::BetaResponseInputItem::FunctionCallOutput::Output::Variants,
                 type: Symbol,
                 id: T.nilable(String),
                 agent: T.nilable(OpenAI::Beta::BetaResponseInputItem::FunctionCallOutput::Agent),
+                call_id: T.nilable(String),
                 caller_: T.nilable(
                   T.any(
                     OpenAI::Beta::BetaResponseInputItem::FunctionCallOutput::Caller::Direct,
diff --git a/rbi/openai/models/responses/response_function_tool_call_output_item.rbi b/rbi/openai/models/responses/response_function_tool_call_output_item.rbi
index ee8953b23..64053909f 100644
--- a/rbi/openai/models/responses/response_function_tool_call_output_item.rbi
+++ b/rbi/openai/models/responses/response_function_tool_call_output_item.rbi
@@ -18,10 +18,6 @@ module OpenAI
         sig { returns(String) }
         attr_accessor :id
 
-        # The unique ID of the function tool call generated by the model.
-        sig { returns(String) }
-        attr_accessor :call_id
-
         # The output from the function call generated by your code. Can be a string or an
         # list of output content.
         sig { returns(OpenAI::Responses::ResponseFunctionToolCallOutputItem::Output::Variants) }
@@ -36,6 +32,13 @@ module OpenAI
         sig { returns(Symbol) }
         attr_accessor :type
 
+        # The unique ID of the function tool call generated by the model.
+        sig { returns(T.nilable(String)) }
+        attr_reader :call_id
+
+        sig { params(call_id: String).void }
+        attr_writer :call_id
+
         # The execution context that produced this tool call.
         sig { returns(T.nilable(OpenAI::Responses::ResponseFunctionToolCallOutputItem::Caller::Variants)) }
         attr_accessor :caller_
@@ -66,12 +69,12 @@ module OpenAI
 
             id: String,
 
-            call_id: String,
-
             output: OpenAI::Responses::ResponseFunctionToolCallOutputItem::Output::Variants,
 
             status: OpenAI::Responses::ResponseFunctionToolCallOutputItem::Status::OrSymbol,
 
+            call_id: String,
+
             caller_: T.nilable(
               T.any(
                 OpenAI::Responses::ResponseFunctionToolCallOutputItem::Caller::Direct::OrHash,
@@ -94,9 +97,6 @@ module OpenAI
           # The unique ID of the function call tool output.
           id:,
 
-          # The unique ID of the function tool call generated by the model.
-          call_id:,
-
           # The output from the function call generated by your code. Can be a string or an
           # list of output content.
           output:,
@@ -105,6 +105,9 @@ module OpenAI
           # Populated when items are returned via API.
           status:,
 
+          # The unique ID of the function tool call generated by the model.
+          call_id: nil,
+
           # The execution context that produced this tool call.
           caller_: nil,
 
@@ -127,10 +130,10 @@ module OpenAI
           override.returns(
             {
               id: String,
-              call_id: String,
               output: OpenAI::Responses::ResponseFunctionToolCallOutputItem::Output::Variants,
               status: OpenAI::Responses::ResponseFunctionToolCallOutputItem::Status::TaggedSymbol,
               type: Symbol,
+              call_id: String,
               caller_: T.nilable(OpenAI::Responses::ResponseFunctionToolCallOutputItem::Caller::Variants),
               created_by: String,
               name: String,
diff --git a/rbi/openai/models/responses/response_input_item.rbi b/rbi/openai/models/responses/response_input_item.rbi
index 64ad6f116..5f7c2ca77 100644
--- a/rbi/openai/models/responses/response_input_item.rbi
+++ b/rbi/openai/models/responses/response_input_item.rbi
@@ -398,10 +398,6 @@ module OpenAI
             )
           end
 
-          # The unique ID of the function tool call generated by the model.
-          sig { returns(String) }
-          attr_accessor :call_id
-
           # Text, image, or file output of the function tool call.
           sig { returns(OpenAI::Responses::ResponseInputItem::FunctionCallOutput::Output::Variants) }
           attr_accessor :output
@@ -415,6 +411,10 @@ module OpenAI
           sig { returns(T.nilable(String)) }
           attr_accessor :id
 
+          # The unique ID of the function tool call generated by the model.
+          sig { returns(T.nilable(String)) }
+          attr_accessor :call_id
+
           # The execution context that produced this tool call.
           sig {
             returns(
@@ -445,12 +445,12 @@ module OpenAI
           sig do
             params(
 
-              call_id: String,
-
               output: OpenAI::Responses::ResponseInputItem::FunctionCallOutput::Output::Variants,
 
               id: T.nilable(String),
 
+              call_id: T.nilable(String),
+
               caller_: T.nilable(
                 T.any(
                   OpenAI::Responses::ResponseInputItem::FunctionCallOutput::Caller::Direct::OrHash,
@@ -470,9 +470,6 @@ module OpenAI
           end
           def self.new(
 
-            # The unique ID of the function tool call generated by the model.
-            call_id:,
-
             # Text, image, or file output of the function tool call.
             output:,
 
@@ -480,6 +477,9 @@ module OpenAI
             # returned via API.
             id: nil,
 
+            # The unique ID of the function tool call generated by the model.
+            call_id: nil,
+
             # The execution context that produced this tool call.
             caller_: nil,
 
@@ -502,10 +502,10 @@ module OpenAI
           sig do
             override.returns(
               {
-                call_id: String,
                 output: OpenAI::Responses::ResponseInputItem::FunctionCallOutput::Output::Variants,
                 type: Symbol,
                 id: T.nilable(String),
+                call_id: T.nilable(String),
                 caller_: T.nilable(
                   T.any(
                     OpenAI::Responses::ResponseInputItem::FunctionCallOutput::Caller::Direct,
diff --git a/sig/openai/models/beta/beta_response_function_tool_call_output_item.rbs b/sig/openai/models/beta/beta_response_function_tool_call_output_item.rbs
index 3835a6e10..8d0d51823 100644
--- a/sig/openai/models/beta/beta_response_function_tool_call_output_item.rbs
+++ b/sig/openai/models/beta/beta_response_function_tool_call_output_item.rbs
@@ -6,11 +6,11 @@ module OpenAI
       type beta_response_function_tool_call_output_item =
         {
           id: String,
-          call_id: String,
           output: OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem::output,
           status: OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem::status,
           type: :function_call_output,
           agent: OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Agent?,
+          call_id: String,
           caller_: OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem::caller_?,
           created_by: String,
           name: String,
@@ -20,8 +20,6 @@ module OpenAI
       class BetaResponseFunctionToolCallOutputItem < OpenAI::Internal::Type::BaseModel
         attr_accessor id: String
 
-        attr_accessor call_id: String
-
         attr_accessor output: OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem::output
 
         attr_accessor status: OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem::status
@@ -30,6 +28,10 @@ module OpenAI
 
         attr_accessor agent: OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Agent?
 
+        attr_reader call_id: String?
+
+        def call_id=: (String) -> String
+
         attr_accessor caller_: OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem::caller_?
 
         attr_reader created_by: String?
@@ -46,10 +48,10 @@ module OpenAI
 
         def initialize: (
           id: String,
-          call_id: String,
           output: OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem::output,
           status: OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem::status,
           ?agent: OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Agent?,
+          ?call_id: String,
           ?caller_: OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem::caller_?,
           ?created_by: String,
           ?name: String,
@@ -59,11 +61,11 @@ module OpenAI
 
         def to_hash: -> {
           id: String,
-          call_id: String,
           output: OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem::output,
           status: OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem::status,
           type: :function_call_output,
           agent: OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Agent?,
+          call_id: String,
           caller_: OpenAI::Models::Beta::BetaResponseFunctionToolCallOutputItem::caller_?,
           created_by: String,
           name: String,
diff --git a/sig/openai/models/beta/beta_response_input_item.rbs b/sig/openai/models/beta/beta_response_input_item.rbs
index c770ab33f..86740c46d 100644
--- a/sig/openai/models/beta/beta_response_input_item.rbs
+++ b/sig/openai/models/beta/beta_response_input_item.rbs
@@ -222,11 +222,11 @@ module OpenAI
 
         type function_call_output =
           {
-            call_id: String,
             output: OpenAI::Models::Beta::BetaResponseInputItem::FunctionCallOutput::output,
             type: :function_call_output,
             id: String?,
             agent: OpenAI::Beta::BetaResponseInputItem::FunctionCallOutput::Agent?,
+            call_id: String?,
             caller_: OpenAI::Models::Beta::BetaResponseInputItem::FunctionCallOutput::caller_?,
             name: String?,
             namespace: String?,
@@ -234,8 +234,6 @@ module OpenAI
           }
 
         class FunctionCallOutput < OpenAI::Internal::Type::BaseModel
-          attr_accessor call_id: String
-
           attr_accessor output: OpenAI::Models::Beta::BetaResponseInputItem::FunctionCallOutput::output
 
           attr_accessor type: :function_call_output
@@ -244,6 +242,8 @@ module OpenAI
 
           attr_accessor agent: OpenAI::Beta::BetaResponseInputItem::FunctionCallOutput::Agent?
 
+          attr_accessor call_id: String?
+
           attr_accessor caller_: OpenAI::Models::Beta::BetaResponseInputItem::FunctionCallOutput::caller_?
 
           attr_accessor name: String?
@@ -253,10 +253,10 @@ module OpenAI
           attr_accessor status: OpenAI::Models::Beta::BetaResponseInputItem::FunctionCallOutput::status?
 
           def initialize: (
-            call_id: String,
             output: OpenAI::Models::Beta::BetaResponseInputItem::FunctionCallOutput::output,
             ?id: String?,
             ?agent: OpenAI::Beta::BetaResponseInputItem::FunctionCallOutput::Agent?,
+            ?call_id: String?,
             ?caller_: OpenAI::Models::Beta::BetaResponseInputItem::FunctionCallOutput::caller_?,
             ?name: String?,
             ?namespace: String?,
@@ -265,11 +265,11 @@ module OpenAI
           ) -> void
 
           def to_hash: -> {
-            call_id: String,
             output: OpenAI::Models::Beta::BetaResponseInputItem::FunctionCallOutput::output,
             type: :function_call_output,
             id: String?,
             agent: OpenAI::Beta::BetaResponseInputItem::FunctionCallOutput::Agent?,
+            call_id: String?,
             caller_: OpenAI::Models::Beta::BetaResponseInputItem::FunctionCallOutput::caller_?,
             name: String?,
             namespace: String?,
diff --git a/sig/openai/models/responses/response_function_tool_call_output_item.rbs b/sig/openai/models/responses/response_function_tool_call_output_item.rbs
index 2e4980e73..8917db4bd 100644
--- a/sig/openai/models/responses/response_function_tool_call_output_item.rbs
+++ b/sig/openai/models/responses/response_function_tool_call_output_item.rbs
@@ -4,10 +4,10 @@ module OpenAI
       type response_function_tool_call_output_item =
         {
           id: String,
-          call_id: String,
           output: OpenAI::Models::Responses::ResponseFunctionToolCallOutputItem::output,
           status: OpenAI::Models::Responses::ResponseFunctionToolCallOutputItem::status,
           type: :function_call_output,
+          call_id: String,
           caller_: OpenAI::Models::Responses::ResponseFunctionToolCallOutputItem::caller_?,
           created_by: String,
           name: String,
@@ -17,14 +17,16 @@ module OpenAI
       class ResponseFunctionToolCallOutputItem < OpenAI::Internal::Type::BaseModel
         attr_accessor id: String
 
-        attr_accessor call_id: String
-
         attr_accessor output: OpenAI::Models::Responses::ResponseFunctionToolCallOutputItem::output
 
         attr_accessor status: OpenAI::Models::Responses::ResponseFunctionToolCallOutputItem::status
 
         attr_accessor type: :function_call_output
 
+        attr_reader call_id: String?
+
+        def call_id=: (String) -> String
+
         attr_accessor caller_: OpenAI::Models::Responses::ResponseFunctionToolCallOutputItem::caller_?
 
         attr_reader created_by: String?
@@ -41,9 +43,9 @@ module OpenAI
 
         def initialize: (
           id: String,
-          call_id: String,
           output: OpenAI::Models::Responses::ResponseFunctionToolCallOutputItem::output,
           status: OpenAI::Models::Responses::ResponseFunctionToolCallOutputItem::status,
+          ?call_id: String,
           ?caller_: OpenAI::Models::Responses::ResponseFunctionToolCallOutputItem::caller_?,
           ?created_by: String,
           ?name: String,
@@ -53,10 +55,10 @@ module OpenAI
 
         def to_hash: -> {
           id: String,
-          call_id: String,
           output: OpenAI::Models::Responses::ResponseFunctionToolCallOutputItem::output,
           status: OpenAI::Models::Responses::ResponseFunctionToolCallOutputItem::status,
           type: :function_call_output,
+          call_id: String,
           caller_: OpenAI::Models::Responses::ResponseFunctionToolCallOutputItem::caller_?,
           created_by: String,
           name: String,
diff --git a/sig/openai/models/responses/response_input_item.rbs b/sig/openai/models/responses/response_input_item.rbs
index ffba7a92c..80fd5a0f1 100644
--- a/sig/openai/models/responses/response_input_item.rbs
+++ b/sig/openai/models/responses/response_input_item.rbs
@@ -187,10 +187,10 @@ module OpenAI
 
         type function_call_output =
           {
-            call_id: String,
             output: OpenAI::Models::Responses::ResponseInputItem::FunctionCallOutput::output,
             type: :function_call_output,
             id: String?,
+            call_id: String?,
             caller_: OpenAI::Models::Responses::ResponseInputItem::FunctionCallOutput::caller_?,
             name: String?,
             namespace: String?,
@@ -198,14 +198,14 @@ module OpenAI
           }
 
         class FunctionCallOutput < OpenAI::Internal::Type::BaseModel
-          attr_accessor call_id: String
-
           attr_accessor output: OpenAI::Models::Responses::ResponseInputItem::FunctionCallOutput::output
 
           attr_accessor type: :function_call_output
 
           attr_accessor id: String?
 
+          attr_accessor call_id: String?
+
           attr_accessor caller_: OpenAI::Models::Responses::ResponseInputItem::FunctionCallOutput::caller_?
 
           attr_accessor name: String?
@@ -215,9 +215,9 @@ module OpenAI
           attr_accessor status: OpenAI::Models::Responses::ResponseInputItem::FunctionCallOutput::status?
 
           def initialize: (
-            call_id: String,
             output: OpenAI::Models::Responses::ResponseInputItem::FunctionCallOutput::output,
             ?id: String?,
+            ?call_id: String?,
             ?caller_: OpenAI::Models::Responses::ResponseInputItem::FunctionCallOutput::caller_?,
             ?name: String?,
             ?namespace: String?,
@@ -226,10 +226,10 @@ module OpenAI
           ) -> void
 
           def to_hash: -> {
-            call_id: String,
             output: OpenAI::Models::Responses::ResponseInputItem::FunctionCallOutput::output,
             type: :function_call_output,
             id: String?,
+            call_id: String?,
             caller_: OpenAI::Models::Responses::ResponseInputItem::FunctionCallOutput::caller_?,
             name: String?,
             namespace: String?,
diff --git a/test/openai/resources/beta/responses/input_items_test.rb b/test/openai/resources/beta/responses/input_items_test.rb
index c3e0a711f..ac4eeafbd 100644
--- a/test/openai/resources/beta/responses/input_items_test.rb
+++ b/test/openai/resources/beta/responses/input_items_test.rb
@@ -82,10 +82,10 @@ def test_list
           } | {
             type: :function_call_output,
             id: String,
-            call_id: String,
             output: OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Output,
             status: OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Status,
             agent: OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Agent | nil,
+            call_id: String | nil,
             caller_: OpenAI::Beta::BetaResponseFunctionToolCallOutputItem::Caller | nil,
             created_by: String | nil,
             name: String | nil,
diff --git a/test/openai/resources/conversations/items_test.rb b/test/openai/resources/conversations/items_test.rb
index 74238ff38..ff60e245b 100644
--- a/test/openai/resources/conversations/items_test.rb
+++ b/test/openai/resources/conversations/items_test.rb
@@ -53,9 +53,9 @@ def test_retrieve_required_params
           } | {
             type: :function_call_output,
             id: String,
-            call_id: String,
             output: OpenAI::Responses::ResponseFunctionToolCallOutputItem::Output,
             status: OpenAI::Responses::ResponseFunctionToolCallOutputItem::Status,
+            call_id: String | nil,
             caller_: OpenAI::Responses::ResponseFunctionToolCallOutputItem::Caller | nil,
             created_by: String | nil,
             name: String | nil,
@@ -263,9 +263,9 @@ def test_list
           } | {
             type: :function_call_output,
             id: String,
-            call_id: String,
             output: OpenAI::Responses::ResponseFunctionToolCallOutputItem::Output,
             status: OpenAI::Responses::ResponseFunctionToolCallOutputItem::Status,
+            call_id: String | nil,
             caller_: OpenAI::Responses::ResponseFunctionToolCallOutputItem::Caller | nil,
             created_by: String | nil,
             name: String | nil,
diff --git a/test/openai/resources/responses/input_items_test.rb b/test/openai/resources/responses/input_items_test.rb
index cc64fa221..62972a6d8 100644
--- a/test/openai/resources/responses/input_items_test.rb
+++ b/test/openai/resources/responses/input_items_test.rb
@@ -76,9 +76,9 @@ def test_list
           } | {
             type: :function_call_output,
             id: String,
-            call_id: String,
             output: OpenAI::Responses::ResponseFunctionToolCallOutputItem::Output,
             status: OpenAI::Responses::ResponseFunctionToolCallOutputItem::Status,
+            call_id: String | nil,
             caller_: OpenAI::Responses::ResponseFunctionToolCallOutputItem::Caller | nil,
             created_by: String | nil,
             name: String | nil,