diff --git a/letta/schemas/agent.py b/letta/schemas/agent.py
index 089f2fd3..da06e6b5 100644
--- a/letta/schemas/agent.py
+++ b/letta/schemas/agent.py
@@ -152,7 +152,7 @@ class CreateAgent(BaseModel, validate_assignment=True):  #
     project: Optional[str] = Field(
         None,
         deprecated=True,
-        description="Deprecated: Project should now be passed via the project-slug header instead of in the request body. If using the sdk, this can be done via the new project_slug field below.",
+        description="Deprecated: Project should now be passed via the X-Project header instead of in the request body. If using the sdk, this can be done via the new x_project field below.",
     )
     tool_exec_environment_variables: Optional[Dict[str, str]] = Field(
         None, description="The environment variables for tool execution specific to this agent."
diff --git a/letta/server/rest_api/routers/v1/agents.py b/letta/server/rest_api/routers/v1/agents.py
index a26baea5..ed8a8178 100644
--- a/letta/server/rest_api/routers/v1/agents.py
+++ b/letta/server/rest_api/routers/v1/agents.py
@@ -114,7 +114,7 @@ def create_agent(
     agent: CreateAgentRequest = Body(...),
     server: "SyncServer" = Depends(get_letta_server),
     user_id: Optional[str] = Header(None, alias="user_id"),  # Extract user_id from header, default to None if not present
-    project_slug: Optional[str] = Header(None, alias="project-slug"),  # Only handled by next js middleware
+    x_project: Optional[str] = Header(None, alias="X-Project"),  # Only handled by next js middleware
 ):
     """
     Create a new agent with the specified configuration.
diff --git a/letta/server/rest_api/routers/v1/identities.py b/letta/server/rest_api/routers/v1/identities.py
index 83766339..24a136d4 100644
--- a/letta/server/rest_api/routers/v1/identities.py
+++ b/letta/server/rest_api/routers/v1/identities.py
@@ -55,7 +55,7 @@ def create_identity(
     identity: IdentityCreate = Body(...),
     server: "SyncServer" = Depends(get_letta_server),
     user_id: Optional[str] = Header(None, alias="user_id"),  # Extract user_id from header, default to None if not present
-    project_slug: Optional[str] = Header(None, alias="project-slug"),  # Only handled by next js middleware
+    x_project: Optional[str] = Header(None, alias="X-Project"),  # Only handled by next js middleware
 ):
     try:
         actor = server.user_manager.get_user_or_default(user_id=user_id)
@@ -71,7 +71,7 @@ def upsert_identity(
     identity: IdentityCreate = Body(...),
     server: "SyncServer" = Depends(get_letta_server),
     user_id: Optional[str] = Header(None, alias="user_id"),  # Extract user_id from header, default to None if not present
-    project_slug: Optional[str] = Header(None, alias="project-slug"),  # Only handled by next js middleware
+    x_project: Optional[str] = Header(None, alias="X-Project"),  # Only handled by next js middleware
 ):
     try:
         actor = server.user_manager.get_user_or_default(user_id=user_id)