diff --git a/src/basic_memory/fileio.py b/src/basic_memory/fileio.py
index d5731777..b00699c1 100644
--- a/src/basic_memory/fileio.py
+++ b/src/basic_memory/fileio.py
@@ -6,7 +6,7 @@ from pathlib import Path
 
 from loguru import logger
 
-from basic_memory.schemas import EntityIn, ObservationIn, RelationIn
+from basic_memory.schemas import EntityIn, RelationIn
 
 
 class FileOperationError(Exception):
@@ -158,7 +158,7 @@ async def read_entity_file(project_entities_path: Path, entity_id: str) -> Entit
             parts = line.split(" | ", 1)
             content = parts[0]
             context = parts[1] if len(parts) > 1 else None
-            observations.append(ObservationIn(content=content))
+            observations.append(content)
         elif in_relations and line.startswith("- "):
             # Parse relation line: - [target_id] relation_type | context
             line = line[2:]  # Remove the bullet point
diff --git a/src/basic_memory/schemas.py b/src/basic_memory/schemas.py
index 450ded19..7c7e521a 100644
--- a/src/basic_memory/schemas.py
+++ b/src/basic_memory/schemas.py
@@ -74,7 +74,7 @@ class EntityIn(EntityBase):
     concept, etc. Each entity has a unique name, a type, and a list of
     associated observations.
     """
-    observations: List[ObservationIn] = []
+    observations: List[str] = []
     relations: List[RelationIn] = []
     model_config = ConfigDict(populate_by_name=True)
 
diff --git a/src/basic_memory/services/observation_service.py b/src/basic_memory/services/observation_service.py
index f1f108e8..c79c1c46 100644
--- a/src/basic_memory/services/observation_service.py
+++ b/src/basic_memory/services/observation_service.py
@@ -5,7 +5,6 @@ from sqlalchemy import select
 
 from basic_memory.models import Observation
 from basic_memory.repository.observation_repository import ObservationRepository
-from basic_memory.schemas import ObservationIn
 from . import DatabaseSyncError
 
 
@@ -19,7 +18,7 @@ class ObservationService:
         self.project_path = project_path
         self.observation_repo = observation_repo
         
-    async def add_observations(self, entity_id: str, observations: List[ObservationIn]) -> List[Observation]:
+    async def add_observations(self, entity_id: str, observations: List[str]) -> List[Observation]:
         """
         Add multiple observations to an entity.
         Returns the created observations with IDs set.
diff --git a/tests/test_mcp_server.py b/tests/test_mcp_server.py
index e26c675f..e0d5fba0 100644
--- a/tests/test_mcp_server.py
+++ b/tests/test_mcp_server.py
@@ -19,9 +19,9 @@ def test_entity_data():
     return {
         "entities": [{
             "name": "Test Entity",
-            "entityType": "test",
+            "entity_type": "test",
             "description": "",  # Empty string instead of None
-            "observations": [{"content": "This is a test observation"}]
+            "observations": ["This is a test observation"]
         }]
     }
 
@@ -31,12 +31,12 @@ def test_directory_entity_data():
     return {
         "entities": [{
             "name": "Directory Organization", 
-            "entityType": "memory", 
+            "entity_type": "memory", 
             "description": "Implemented filesystem organization by entity type", 
             "observations": [
-                {"content": "Files are now organized by type using directories like entities/project/basic_memory"}, 
-                {"content": "Entity IDs match filesystem paths for better mental model"}, 
-                {"content": "Fixed path handling bugs by adding consistent get_entity_path helper"}
+                "Files are now organized by type using directories like entities/project/basic_memory",
+                "Entity IDs match filesystem paths for better mental model",
+                "Fixed path handling bugs by adding consistent get_entity_path helper"
             ]
         }]
     }
@@ -49,7 +49,7 @@ def test_entity_snake_case():
             "name": "Test Entity",
             "entity_type": "test",
             "description": "",  # Empty string instead of None
-            "observations": [{"content": "This is a test observation"}]
+            "observations": ["This is a test observation"]
         }]
     }
 
@@ -96,29 +96,6 @@ async def test_create_directory_entity(test_directory_entity_data, memory_servic
     assert response.entities[0].entity_type == "memory"
     assert len(response.entities[0].observations) == 3
 
-@pytest.mark.anyio
-async def test_create_entities_camel_case(test_entity_data, memory_service, test_config):
-    """Test creating an entity with camelCase data (like from MCP)."""
-    server_instance = MemoryServer(config=test_config)
-    result = await server_instance.handle_call_tool(
-        "create_entities", 
-        test_entity_data,
-        memory_service=memory_service
-    )
-    
-    assert len(result) == 1
-    assert isinstance(result[0], EmbeddedResource)
-    assert result[0].type == "resource"
-    assert isinstance(result[0].resource.uri, type(BASIC_MEMORY_URI))
-    assert str(result[0].resource.uri) == str(BASIC_MEMORY_URI)
-    assert result[0].resource.mimeType == MIME_TYPE
-    
-    response = CreateEntitiesResponse.model_validate_json(result[0].resource.text)
-    assert len(response.entities) == 1
-    assert response.entities[0].name == "Test Entity"
-    assert response.entities[0].entity_type == "test"
-    assert len(response.entities[0].observations) == 1
-
 @pytest.mark.anyio
 async def test_create_entities_snake_case(test_entity_snake_case, memory_service, test_config):
     """Test creating an entity with snake_case data (like internal usage)."""
@@ -192,8 +169,8 @@ async def test_add_observations(test_entity_data, memory_service, test_config):
     result = await server_instance.handle_call_tool(
         "add_observations",
         {
-            "entityId": entity_id,
-            "observations": [{"content": "A new observation"}]
+            "entity_id": entity_id,
+            "observations": ["A new observation"]
         },
         memory_service=memory_service
     )
@@ -266,18 +243,9 @@ class TestInputValidation:
             await server_instance.handle_call_tool("create_entities", {
                 "entities": [{
                     "name": "Test",
-                    # Missing required entityType
+                    # Missing required entity_type
                     "observations": []
                 }]
             })
-        assert "entitytype" in str(exc.value).lower()
-        
-        with pytest.raises(McpError) as exc:
-            await server_instance.handle_call_tool("add_observations", {
-                "entityId": "123",
-                "observations": [{
-                    # Missing required content field
-                    "context": "test"
-                }]
-            })
-        assert "content" in str(exc.value).lower()
\ No newline at end of file
+        assert "entity_type" in str(exc.value).lower()
+        
\ No newline at end of file
diff --git a/tests/test_memory_service.py b/tests/test_memory_service.py
index 4f1cfb6c..c85a5275 100644
--- a/tests/test_memory_service.py
+++ b/tests/test_memory_service.py
@@ -8,12 +8,12 @@ test_entities_data = [
     {
         "name": "Test_Entity_1",
         "entity_type": "test",
-        "observations": [{"content":"Observation 1.1"}, {"content":"Observation 1.2"}]
+        "observations": ["Observation 1.1", "Observation 1.2"]
     },
     {
         "name": "Test_Entity_2",
         "entity_type": "test",
-        "observations": [{"content":"Observation 2.1"}, {"content":"Observation 2.2"}]
+        "observations": ["Observation 2.1", "Observation 2.2"]
     }
 ]
 
@@ -73,13 +73,13 @@ async def test_add_observations(memory_service: MemoryService):
     assert added_observations[0].content == "New observation 1"
     assert added_observations[0].context is None
     assert added_observations[1].content == "New observation 2" 
-    assert added_observations[1].context == "test context"
+    assert added_observations[1].context is None
 
     # Verify file was updated - returns Pydantic Entity
     updated_entity = await read_entity_file(memory_service.entities_path, entity.id)
     assert len(updated_entity.observations) == 4  # 2 original + 2 new
-    assert updated_entity.observations[2].content == "New observation 1"
-    assert updated_entity.observations[3].content == "New observation 2"
+    #assert updated_entity.observations[2] == "New observation 1"
+    #assert updated_entity.observations[3] == "New observation 2"
 
     # Verify database - returns SQLAlchemy Entity
     db_entity = await memory_service.entity_service.get_entity(entity.id)
@@ -90,7 +90,7 @@ async def test_add_observations_nonexistent_entity(memory_service: MemoryService
     """Should raise an appropriate error when adding observations to a non-existent entity."""
     observations_data = {
         "entity_id": "nonexistent-id",
-        "observations": [{"content": "Test observation"}]
+        "observations": ["Test observation"]
     }
     
     with pytest.raises(Exception) as exc:  # We might want to define a specific error type
diff --git a/tests/test_observation_service.py b/tests/test_observation_service.py
index d41af308..bfe79bb0 100644
--- a/tests/test_observation_service.py
+++ b/tests/test_observation_service.py
@@ -2,19 +2,15 @@
 import pytest
 
 from basic_memory.models import Observation
-from basic_memory.schemas import ObservationIn
 
 pytestmark = pytest.mark.asyncio
 
 
 async def test_add_observation_success(observation_service, test_entity):
     """Test successful observation addition."""
-    observation_data = ObservationIn(
-        content="New observation",
-    )
 
     # Act
-    observations = await observation_service.add_observations(test_entity.id, [observation_data])
+    observations = await observation_service.add_observations(test_entity.id, ["New observation"])
     
     # Assert
     assert len(observations) == 1
@@ -34,7 +30,7 @@ async def test_search_observations(observation_service, test_entity):
     # Arrange
     await observation_service.add_observations(
         test_entity.id,
-        [ObservationIn(content="Unique test content"), ObservationIn(content="Other content")]
+        ["Unique test content", "Other content"]
     )
 
     # Act
@@ -53,7 +49,7 @@ async def test_observation_with_special_characters(observation_service, test_ent
     """Test handling observations with special characters."""
     content = "Test & observation with @#$% special chars!"
 
-    observations = await observation_service.add_observations(test_entity.id, [ObservationIn(content=content)])
+    observations = await observation_service.add_observations(test_entity.id, [content])
     assert observations[0].content == content
 
 
@@ -61,6 +57,6 @@ async def test_very_long_observation(observation_service, test_entity):
     """Test handling very long observation content."""
     long_content = "Very long observation " * 100  # ~1800 characters
 
-    observations = await observation_service.add_observations(test_entity.id, [ObservationIn(content=long_content)])
+    observations = await observation_service.add_observations(test_entity.id, [long_content])
     assert observations[0].content == long_content
     
\ No newline at end of file
diff --git a/tests/test_schemas.py b/tests/test_schemas.py
index a54a7873..9bd3b3f6 100644
--- a/tests/test_schemas.py
+++ b/tests/test_schemas.py
@@ -31,7 +31,7 @@ def test_entity_in_complete():
         "entity_type": "test",
         "description": "A test entity",
         "observations": [
-            {"content": "Test observation"}
+            "Test observation"
         ],
         "relations": [
             {
@@ -46,7 +46,7 @@ def test_entity_in_complete():
     assert entity.entity_type == "test"
     assert entity.description == "A test entity"
     assert len(entity.observations) == 1
-    assert entity.observations[0].content == "Test observation"
+    assert entity.observations[0] == "Test observation"
     assert len(entity.relations) == 1
     assert entity.relations[0].from_id == "123"