diff --git a/servers/fastapi/ppt_generator/models/content_type_models.py b/servers/fastapi/ppt_generator/models/content_type_models.py
index 4d6b1513..01145157 100644
--- a/servers/fastapi/ppt_generator/models/content_type_models.py
+++ b/servers/fastapi/ppt_generator/models/content_type_models.py
@@ -1,4 +1,4 @@
-from typing import List, Mapping
+from typing import List, Mapping, Union
 from pydantic import BaseModel
 
 from ppt_generator.models.other_models import (
@@ -196,7 +196,19 @@ class Type9Content(SlideContentModel):
         )
 
 
-CONTENT_TYPE_MAPPING: Mapping[int, SlideContentModel] = {
+ContentUnion = Union[
+    Type1Content,
+    Type2Content,
+    Type3Content,
+    Type4Content,
+    Type5Content,
+    Type6Content,
+    Type7Content,
+    Type8Content,
+    Type9Content,
+]
+
+CONTENT_TYPE_MAPPING: Mapping[int, ContentUnion] = {
     TYPE1: Type1Content,
     TYPE2: Type2Content,
     TYPE3: Type3Content,
diff --git a/servers/fastapi/ppt_generator/models/llm_models.py b/servers/fastapi/ppt_generator/models/llm_models.py
index a08292e8..a8a08456 100644
--- a/servers/fastapi/ppt_generator/models/llm_models.py
+++ b/servers/fastapi/ppt_generator/models/llm_models.py
@@ -1,4 +1,4 @@
-from typing import List, Literal, Mapping
+from typing import List, Literal, Mapping, Union
 from pydantic import BaseModel, Field
 
 from ppt_generator.models.content_type_models import (
@@ -55,6 +55,10 @@ class LLMHeadingModel(BaseModel):
         )
 
 
+class LLMHeadingModelNew(LLMHeadingModel):
+    pass
+
+
 class LLMHeadingModelWithImagePrompt(LLMHeadingModel):
     image_prompt: str = Field(
         description="Item image prompt in less than 5 words",
@@ -89,7 +93,7 @@ class LLMSlideContentModel(BaseModel):
 
 
 class LLMType1Content(LLMSlideContentModel):
-    type: Literal["1"] = "1"
+    content_type: Literal["1"] = "1"
     body: str = Field(
         description="Slide content summary in less than 30 words.",
     )
@@ -106,8 +110,11 @@ class LLMType1Content(LLMSlideContentModel):
 
 
 class LLMType2Content(LLMSlideContentModel):
-    type: Literal["2"] = "2"
-    body: List[LLMHeadingModel] = Field(
+    content_type: Literal["2"] = Field(
+        "2",
+        description="Content type",
+    )
+    body: List[LLMHeadingModelNew] = Field(
         description="Items to show in slide",
         min_length=1,
         max_length=4,
@@ -121,7 +128,7 @@ class LLMType2Content(LLMSlideContentModel):
 
 
 class LLMType3Content(LLMSlideContentModel):
-    type: Literal["3"] = "3"
+    content_type: Literal["3"] = "3"
     body: List[LLMHeadingModel] = Field(
         description="Items to show in slide",
         min_length=3,
@@ -140,7 +147,7 @@ class LLMType3Content(LLMSlideContentModel):
 
 
 class LLMType4Content(LLMSlideContentModel):
-    type: Literal["4"] = "4"
+    content_type: Literal["4"] = "4"
     body: List[LLMHeadingModelWithImagePrompt] = Field(
         description="Items to show in slide",
         min_length=1,
@@ -156,7 +163,7 @@ class LLMType4Content(LLMSlideContentModel):
 
 
 class LLMType5Content(LLMSlideContentModel):
-    type: Literal["5"] = "5"
+    content_type: Literal["5"] = "5"
     body: str = Field(
         description="Slide content summary in less than 30 words.",
     )
@@ -171,11 +178,14 @@ class LLMType5Content(LLMSlideContentModel):
 
 
 class LLMType6Content(LLMSlideContentModel):
-    type: Literal["6"] = "6"
+    content_type: Literal["6"] = Field(
+        "6",
+        description="Content type",
+    )
     description: str = Field(
         description="Slide content summary in less than 20 words.",
     )
-    body: List[LLMHeadingModel] = Field(
+    body: List[LLMHeadingModelNew] = Field(
         description="Items to show in slide",
         min_length=1,
         max_length=3,
@@ -190,7 +200,7 @@ class LLMType6Content(LLMSlideContentModel):
 
 
 class LLMType7Content(LLMSlideContentModel):
-    type: Literal["7"] = "7"
+    content_type: Literal["7"] = "7"
     body: List[LLMHeadingModelWithIconQuery] = Field(
         description="Items to show in slide",
         min_length=1,
@@ -206,7 +216,7 @@ class LLMType7Content(LLMSlideContentModel):
 
 
 class LLMType8Content(LLMSlideContentModel):
-    type: Literal["8"] = "8"
+    content_type: Literal["8"] = "8"
     description: str = Field(
         description="Slide content summary in less than 20 words.",
     )
@@ -226,7 +236,7 @@ class LLMType8Content(LLMSlideContentModel):
 
 
 class LLMType9Content(LLMSlideContentModel):
-    type: Literal["9"] = "9"
+    content_type: Literal["9"] = "9"
     body: List[LLMHeadingModel] = Field(
         description="Items to show in slide",
         min_length=1,
@@ -254,20 +264,26 @@ LLM_CONTENT_TYPE_MAPPING: Mapping[int, LLMSlideContentModel] = {
     TYPE9: LLMType9Content,
 }
 
+LLMContentUnion = Union[
+    # LLMType1Content,
+    LLMType2Content,
+    # LLMType3Content,
+    # LLMType4Content,
+    # LLMType5Content,
+    LLMType6Content,
+    # LLMType7Content,
+    # LLMType8Content,
+    # LLMType9Content,
+]
+
 
 class LLMSlideModel(BaseModel):
     type: int
-    content: (
-        LLMType1Content
-        | LLMType2Content
-        | LLMType4Content
-        | LLMType5Content
-        | LLMType6Content
-        # | LLMType7Content
-        # | LLMType8Content
-        # | LLMType9Content
+    content: LLMContentUnion = Field(
+        description="Content of the slide",
+        discriminator="content_type",
     )
 
 
 class LLMPresentationModel(BaseModel):
-    slides: list[LLMSlideModel]
+    slides: List[LLMSlideModel]
diff --git a/servers/fastapi/ppt_generator/slide_generator.py b/servers/fastapi/ppt_generator/slide_generator.py
index c3ca4b87..31a1bbf9 100644
--- a/servers/fastapi/ppt_generator/slide_generator.py
+++ b/servers/fastapi/ppt_generator/slide_generator.py
@@ -7,6 +7,7 @@ from ppt_config_generator.models import SlideMarkdownModel
 
 from ppt_generator.models.llm_models import (
     LLM_CONTENT_TYPE_MAPPING,
+    LLMContentUnion,
 )
 from ppt_generator.models.other_models import SlideTypeModel
 from ppt_generator.models.slide_model import SlideModel
@@ -115,7 +116,7 @@ def get_prompt_to_select_slide_type(prompt: str, slide_data: dict, slide_type: i
 
 async def get_slide_content_from_type_and_outline(
     slide_type: int, outline: SlideMarkdownModel
-) -> BaseModel:
+) -> LLMContentUnion:
     response_model = LLM_CONTENT_TYPE_MAPPING[slide_type]
 
     client = get_llm_client()
@@ -139,7 +140,7 @@ async def get_edited_slide_content_model(
     slide: SlideModel,
     theme: Optional[dict] = None,
     language: Optional[str] = None,
-):
+) -> LLMContentUnion:
     client = get_llm_client()
     model = get_large_model()