fix chat completions stream response type

openapi.yaml

@@ -2293,6 +2293,7 @@ components:
                       type: integer
               finish_reason:
                 type: string
+                enum: ["stop", "length"]
         usage:
           type: object
           properties:
@@ -2369,6 +2370,7 @@ components:
         content:
           type: string
           description: The contents of the message.
+          nullable: true
         function_call:
           type: object
           description: The name and arguments of a function that should be called, as generated by the model.
@@ -2381,6 +2383,28 @@ components:
               description: The arguments to call the function with, as generated by the model in JSON format. Note that the model does not always generate valid JSON, and may hallucinate parameters not defined by your function schema. Validate the arguments in your code before calling your function.
       required: 
         - role
+
+    ChatCompletionStreamResponseDelta:
+      type: object
+      properties:
+        role:
+          type: string
+          enum: ["system", "user", "assistant", "function"]
+          description: The role of the author of this message.
+        content:
+          type: string
+          description: The contents of the chunk message.
+          nullable: true
+        function_call:
+          type: object
+          description: The name and arguments of a function that should be called, as generated by the model.
+          properties:
+            name:
+              type: string
+              description: The name of the function to call.
+            arguments:
+              type: string
+              description: The arguments to call the function with, as generated by the model in JSON format. Note that the model does not always generate valid JSON, and may hallucinate parameters not defined by your function schema. Validate the arguments in your code before calling your function.
 
     CreateChatCompletionRequest:
       type: object
@@ -2512,6 +2536,7 @@ components:
                 $ref: '#/components/schemas/ChatCompletionResponseMessage'
               finish_reason:
                 type: string
+                enum: ["stop", "length", "function_call"]
         usage:
           type: object
           properties:
@@ -2532,6 +2557,36 @@ components:
         - model
         - choices
 
+    CreateChatCompletionStreamResponse:
+      type: object
+      properties:
+        id:
+          type: string
+        object:
+          type: string
+        created:
+          type: integer
+        model:
+          type: string
+        choices:
+          type: array
+          items:
+            type: object
+            properties:
+              index:
+                type: integer
+              delta:
+                $ref: '#/components/schemas/ChatCompletionStreamResponseDelta'
+              finish_reason:
+                type: string
+                enum: ["stop", "length", "function_call"]
+      required: 
+        - id
+        - object
+        - created
+        - model
+        - choices
+
     CreateEditRequest:
       type: object
       properties:
@@ -2617,6 +2672,7 @@ components:
                       type: integer
               finish_reason:
                 type: string
+                enum: ["stop", "length"]
         usage:
           type: object
           properties: