diff --git a/letta/agent.py b/letta/agent.py
index 810f821513..532c4e13a7 100644
--- a/letta/agent.py
+++ b/letta/agent.py
@@ -18,7 +18,7 @@
     MESSAGE_SUMMARY_WARNING_FRAC,
     O1_BASE_TOOLS,
     REQ_HEARTBEAT_MESSAGE,
-    STRUCTURED_OUTPUT_MODELS
+    STRUCTURED_OUTPUT_MODELS,
 )
 from letta.errors import LLMError
 from letta.helpers import ToolRulesSolver
@@ -260,9 +260,6 @@ def __init__(
 
         self.user = user
 
-        # link tools
-        self.link_tools(agent_state.tools)
-
         # initialize a tool rules solver
         if agent_state.tool_rules:
             # if there are tool rules, print out a warning
@@ -385,7 +382,9 @@ def __init__(
     def check_tool_rules(self):
         if self.model not in STRUCTURED_OUTPUT_MODELS:
             if len(self.tool_rules_solver.init_tool_rules) > 1:
-                raise ValueError("Multiple initial tools are not supported for non-structured models. Please use only one initial tool rule.")
+                raise ValueError(
+                    "Multiple initial tools are not supported for non-structured models. Please use only one initial tool rule."
+                )
             self.supports_structured_output = False
         else:
             self.supports_structured_output = True
@@ -424,11 +423,21 @@ def update_memory_if_change(self, new_memory: Memory) -> bool:
             return True
         return False
 
-    def execute_tool_and_persist_state(self, function_name, function_to_call, function_args):
+    def execute_tool_and_persist_state(self, function_name: str, function_args: dict, target_letta_tool: Tool):
         """
         Execute tool modifications and persist the state of the agent.
         Note: only some agent state modifications will be persisted, such as data in the AgentState ORM and block data
         """
+        # TODO: Get rid of this. This whole piece is pretty shady, that we exec the function to just get the type hints for args.
+        env = {}
+        env.update(globals())
+        exec(target_letta_tool.source_code, env)
+        callable_func = env[target_letta_tool.json_schema["name"]]
+        spec = inspect.getfullargspec(callable_func).annotations
+        for name, arg in function_args.items():
+            if isinstance(function_args[name], dict):
+                function_args[name] = spec[name](**function_args[name])
+
         # TODO: add agent manager here
         orig_memory_str = self.agent_state.memory.compile()
 
@@ -441,11 +450,11 @@ def execute_tool_and_persist_state(self, function_name, function_to_call, functi
             if function_name in BASE_TOOLS or function_name in O1_BASE_TOOLS:
                 # base tools are allowed to access the `Agent` object and run on the database
                 function_args["self"] = self  # need to attach self to arg since it's dynamically linked
-                function_response = function_to_call(**function_args)
+                function_response = callable_func(**function_args)
             else:
                 # execute tool in a sandbox
                 # TODO: allow agent_state to specify which sandbox to execute tools in
-                sandbox_run_result = ToolExecutionSandbox(function_name, function_args, self.agent_state.created_by_id).run(
+                sandbox_run_result = ToolExecutionSandbox(function_name, function_args, self.user).run(
                     agent_state=self.agent_state.__deepcopy__()
                 )
                 function_response, updated_agent_state = sandbox_run_result.func_return, sandbox_run_result.agent_state
@@ -470,27 +479,6 @@ def messages(self) -> List[dict]:
     def messages(self, value):
         raise Exception("Modifying message list directly not allowed")
 
-    def link_tools(self, tools: List[Tool]):
-        """Bind a tool object (schema + python function) to the agent object"""
-
-        # Store the functions schemas (this is passed as an argument to ChatCompletion)
-        self.functions = []
-        self.functions_python = {}
-        env = {}
-        env.update(globals())
-        for tool in tools:
-            try:
-                # WARNING: name may not be consistent?
-                # if tool.module:  # execute the whole module
-                #    exec(tool.module, env)
-                # else:
-                exec(tool.source_code, env)
-                self.functions_python[tool.json_schema["name"]] = env[tool.json_schema["name"]]
-                self.functions.append(tool.json_schema)
-            except Exception:
-                warnings.warn(f"WARNING: tool {tool.name} failed to link")
-        assert all([callable(f) for k, f in self.functions_python.items()]), self.functions_python
-
     def _load_messages_from_recall(self, message_ids: List[str]) -> List[Message]:
         """Load a list of messages from recall storage"""
 
@@ -599,8 +587,12 @@ def _get_ai_reply(
         """Get response from LLM API with robust retry mechanism."""
 
         allowed_tool_names = self.tool_rules_solver.get_allowed_tool_names()
+        agent_state_tool_jsons = [t.json_schema for t in self.agent_state.tools]
+
         allowed_functions = (
-            self.functions if not allowed_tool_names else [func for func in self.functions if func["name"] in allowed_tool_names]
+            agent_state_tool_jsons
+            if not allowed_tool_names
+            else [func for func in agent_state_tool_jsons if func["name"] in allowed_tool_names]
         )
 
         # For the first message, force the initial tool if one is specified
@@ -620,7 +612,7 @@ def _get_ai_reply(
                     messages=message_sequence,
                     user_id=self.agent_state.created_by_id,
                     functions=allowed_functions,
-                    functions_python=self.functions_python,
+                    # functions_python=self.functions_python, do we need this?
                     function_call=function_call,
                     first_message=first_message,
                     force_tool_call=force_tool_call,
@@ -729,10 +721,13 @@ def _handle_ai_response(
             function_name = function_call.name
             printd(f"Request to call function {function_name} with tool_call_id: {tool_call_id}")
 
-            # Failure case 1: function name is wrong
-            try:
-                function_to_call = self.functions_python[function_name]
-            except KeyError:
+            # Failure case 1: function name is wrong (not in agent_state.tools)
+            target_letta_tool = None
+            for t in self.agent_state.tools:
+                if t.name == function_name:
+                    target_letta_tool = t
+
+            if not target_letta_tool:
                 error_msg = f"No function named {function_name}"
                 function_response = package_function_response(False, error_msg)
                 messages.append(
@@ -800,14 +795,8 @@ def _handle_ai_response(
             #       this is because the function/tool role message is only created once the function/tool has executed/returned
             self.interface.function_message(f"Running {function_name}({function_args})", msg_obj=messages[-1])
             try:
-                spec = inspect.getfullargspec(function_to_call).annotations
-
-                for name, arg in function_args.items():
-                    if isinstance(function_args[name], dict):
-                        function_args[name] = spec[name](**function_args[name])
-
                 # handle tool execution (sandbox) and state updates
-                function_response = self.execute_tool_and_persist_state(function_name, function_to_call, function_args)
+                function_response = self.execute_tool_and_persist_state(function_name, function_args, target_letta_tool)
 
                 # handle trunction
                 if function_name in ["conversation_search", "conversation_search_date", "archival_memory_search"]:
@@ -819,8 +808,7 @@ def _handle_ai_response(
                     truncate = True
 
                 # get the function response limit
-                tool_obj = [tool for tool in self.agent_state.tools if tool.name == function_name][0]
-                return_char_limit = tool_obj.return_char_limit
+                return_char_limit = target_letta_tool.return_char_limit
                 function_response_string = validate_function_response(
                     function_response, return_char_limit=return_char_limit, truncate=truncate
                 )
@@ -1564,9 +1552,10 @@ def get_context_window(self) -> ContextWindowOverview:
         num_tokens_external_memory_summary = count_tokens(external_memory_summary)
 
         # tokens taken up by function definitions
-        if self.functions:
-            available_functions_definitions = [ChatCompletionRequestTool(type="function", function=f) for f in self.functions]
-            num_tokens_available_functions_definitions = num_tokens_from_functions(functions=self.functions, model=self.model)
+        agent_state_tool_jsons = [t.json_schema for t in self.agent_state.tools]
+        if agent_state_tool_jsons:
+            available_functions_definitions = [ChatCompletionRequestTool(type="function", function=f) for f in agent_state_tool_jsons]
+            num_tokens_available_functions_definitions = num_tokens_from_functions(functions=agent_state_tool_jsons, model=self.model)
         else:
             available_functions_definitions = []
             num_tokens_available_functions_definitions = 0
diff --git a/letta/server/rest_api/routers/v1/tools.py b/letta/server/rest_api/routers/v1/tools.py
index e1eb591951..61b89624d4 100644
--- a/letta/server/rest_api/routers/v1/tools.py
+++ b/letta/server/rest_api/routers/v1/tools.py
@@ -195,7 +195,7 @@ def run_tool_from_source(
             tool_source_type=request.source_type,
             tool_args=request.args,
             tool_name=request.name,
-            user_id=actor.id,
+            actor=actor,
         )
     except LettaToolCreateError as e:
         # HTTP 400 == Bad Request
diff --git a/letta/server/server.py b/letta/server/server.py
index fa9ca8ed9f..31c87394d7 100644
--- a/letta/server/server.py
+++ b/letta/server/server.py
@@ -853,10 +853,6 @@ def update_agent(
             # then (2) setting the attributes ._messages and .state.message_ids
             letta_agent.set_message_buffer(message_ids=request.message_ids)
 
-        # tools
-        if request.tool_ids:
-            letta_agent.link_tools(letta_agent.agent_state.tools)
-
         letta_agent.update_state()
 
         return agent_state
@@ -882,11 +878,6 @@ def add_tool_to_agent(
 
         agent_state = self.agent_manager.attach_tool(agent_id=agent_id, tool_id=tool_id, actor=actor)
 
-        # TODO: This is very redundant, and should probably be simplified
-        # Get the agent object (loaded in memory)
-        letta_agent = self.load_agent(agent_id=agent_id, actor=actor)
-        letta_agent.link_tools(agent_state.tools)
-
         return agent_state
 
     def remove_tool_from_agent(
@@ -900,10 +891,6 @@ def remove_tool_from_agent(
         actor = self.user_manager.get_user_or_default(user_id=user_id)
         agent_state = self.agent_manager.detach_tool(agent_id=agent_id, tool_id=tool_id, actor=actor)
 
-        # Get the agent object (loaded in memory)
-        letta_agent = self.load_agent(agent_id=agent_id, actor=actor)
-        letta_agent.link_tools(agent_state.tools)
-
         return agent_state
 
     # convert name->id
@@ -1309,9 +1296,7 @@ def get_llm_config_from_handle(self, handle: str, context_window_limit: Optional
 
         if context_window_limit:
             if context_window_limit > llm_config.context_window:
-                raise ValueError(
-                    f"Context window limit ({context_window_limit}) is greater than maximum of ({llm_config.context_window})"
-                )
+                raise ValueError(f"Context window limit ({context_window_limit}) is greater than maximum of ({llm_config.context_window})")
             llm_config.context_window = context_window_limit
 
         return llm_config
@@ -1366,7 +1351,7 @@ def get_agent_context_window(
 
     def run_tool_from_source(
         self,
-        user_id: str,
+        actor: User,
         tool_args: str,
         tool_source: str,
         tool_source_type: Optional[str] = None,
@@ -1394,7 +1379,7 @@ def run_tool_from_source(
 
         # Next, attempt to run the tool with the sandbox
         try:
-            sandbox_run_result = ToolExecutionSandbox(tool.name, tool_args_dict, user_id, tool_object=tool).run(agent_state=agent_state)
+            sandbox_run_result = ToolExecutionSandbox(tool.name, tool_args_dict, actor, tool_object=tool).run(agent_state=agent_state)
             return FunctionReturn(
                 id="null",
                 function_call_id="null",
@@ -1406,9 +1391,7 @@ def run_tool_from_source(
             )
 
         except Exception as e:
-            func_return = get_friendly_error_msg(
-                function_name=tool.name, exception_name=type(e).__name__, exception_message=str(e)
-            )   
+            func_return = get_friendly_error_msg(function_name=tool.name, exception_name=type(e).__name__, exception_message=str(e))
             return FunctionReturn(
                 id="null",
                 function_call_id="null",
diff --git a/letta/services/tool_execution_sandbox.py b/letta/services/tool_execution_sandbox.py
index b6004c3c74..fc6e1bdd38 100644
--- a/letta/services/tool_execution_sandbox.py
+++ b/letta/services/tool_execution_sandbox.py
@@ -16,9 +16,9 @@
 from letta.schemas.agent import AgentState
 from letta.schemas.sandbox_config import SandboxConfig, SandboxRunResult, SandboxType
 from letta.schemas.tool import Tool
+from letta.schemas.user import User
 from letta.services.sandbox_config_manager import SandboxConfigManager
 from letta.services.tool_manager import ToolManager
-from letta.services.user_manager import UserManager
 from letta.settings import tool_settings
 from letta.utils import get_friendly_error_msg
 
@@ -38,14 +38,10 @@ class ToolExecutionSandbox:
     # We make this a long random string to avoid collisions with any variables in the user's code
     LOCAL_SANDBOX_RESULT_VAR_NAME = "result_ZQqiequkcFwRwwGQMqkt"
 
-    def __init__(self, tool_name: str, args: dict, user_id: str, force_recreate=False, tool_object: Optional[Tool] = None):
+    def __init__(self, tool_name: str, args: dict, user: User, force_recreate=False, tool_object: Optional[Tool] = None):
         self.tool_name = tool_name
         self.args = args
-
-        # Get the user
-        # This user corresponds to the agent_state's user_id field
-        # agent_state is the state of the agent that invoked this run
-        self.user = UserManager().get_user_by_id(user_id=user_id)
+        self.user = user
 
         # If a tool object is provided, we use it directly, otherwise pull via name
         if tool_object is not None:
@@ -184,7 +180,9 @@ def run_local_dir_sandbox_venv(self, sbx_config: SandboxConfig, env: Dict[str, s
         except subprocess.CalledProcessError as e:
             logger.error(f"Executing tool {self.tool_name} has process error: {e}")
             func_return = get_friendly_error_msg(
-                function_name=self.tool_name, exception_name=type(e).__name__, exception_message=str(e),
+                function_name=self.tool_name,
+                exception_name=type(e).__name__,
+                exception_message=str(e),
             )
             return SandboxRunResult(
                 func_return=func_return,
@@ -202,9 +200,7 @@ def run_local_dir_sandbox_venv(self, sbx_config: SandboxConfig, env: Dict[str, s
             logger.error(f"Executing tool {self.tool_name} has an unexpected error: {e}")
             raise e
 
-    def run_local_dir_sandbox_runpy(
-        self, sbx_config: SandboxConfig, env_vars: Dict[str, str], temp_file_path: str
-    ) -> SandboxRunResult:
+    def run_local_dir_sandbox_runpy(self, sbx_config: SandboxConfig, env_vars: Dict[str, str], temp_file_path: str) -> SandboxRunResult:
         status = "success"
         agent_state, stderr = None, None
 
@@ -225,9 +221,7 @@ def run_local_dir_sandbox_runpy(
             func_return, agent_state = self.parse_best_effort(func_result)
 
         except Exception as e:
-            func_return = get_friendly_error_msg(
-                function_name=self.tool_name, exception_name=type(e).__name__, exception_message=str(e)
-            )
+            func_return = get_friendly_error_msg(function_name=self.tool_name, exception_name=type(e).__name__, exception_message=str(e))
             traceback.print_exc(file=sys.stderr)
             status = "error"
 
@@ -248,7 +242,7 @@ def run_local_dir_sandbox_runpy(
 
     def parse_out_function_results_markers(self, text: str):
         if self.LOCAL_SANDBOX_RESULT_START_MARKER not in text:
-            return '', text
+            return "", text
         marker_len = len(self.LOCAL_SANDBOX_RESULT_START_MARKER)
         start_index = text.index(self.LOCAL_SANDBOX_RESULT_START_MARKER) + marker_len
         end_index = text.index(self.LOCAL_SANDBOX_RESULT_END_MARKER)
@@ -293,6 +287,7 @@ def run_e2b_sandbox(self, agent_state: AgentState) -> SandboxRunResult:
         env_vars = self.sandbox_config_manager.get_sandbox_env_vars_as_dict(sandbox_config_id=sbx_config.id, actor=self.user, limit=100)
         code = self.generate_execution_script(agent_state=agent_state)
         execution = sbx.run_code(code, envs=env_vars)
+
         if execution.results:
             func_return, agent_state = self.parse_best_effort(execution.results[0].text)
         elif execution.error:
@@ -303,7 +298,7 @@ def run_e2b_sandbox(self, agent_state: AgentState) -> SandboxRunResult:
             execution.logs.stderr.append(execution.error.traceback)
         else:
             raise ValueError(f"Tool {self.tool_name} returned execution with None")
-        
+
         return SandboxRunResult(
             func_return=func_return,
             agent_state=agent_state,
diff --git a/tests/helpers/endpoints_helper.py b/tests/helpers/endpoints_helper.py
index fbe7ffb60b..ddaa1d960d 100644
--- a/tests/helpers/endpoints_helper.py
+++ b/tests/helpers/endpoints_helper.py
@@ -110,8 +110,7 @@ def check_first_response_is_valid_for_llm_endpoint(filename: str) -> ChatComplet
         llm_config=agent_state.llm_config,
         user_id=str(uuid.UUID(int=1)),  # dummy user_id
         messages=agent._messages,
-        functions=agent.functions,
-        functions_python=agent.functions_python,
+        functions=[t.json_schema for t in agent.agent_state.tools],
     )
 
     # Basic check
diff --git a/tests/integration_test_tool_execution_sandbox.py b/tests/integration_test_tool_execution_sandbox.py
index 1b29073f43..299e1e967b 100644
--- a/tests/integration_test_tool_execution_sandbox.py
+++ b/tests/integration_test_tool_execution_sandbox.py
@@ -283,12 +283,12 @@ def test_local_sandbox_default(mock_e2b_api_key_none, add_integers_tool, test_us
 
     # Mock and assert correct pathway was invoked
     with patch.object(ToolExecutionSandbox, "run_local_dir_sandbox") as mock_run_local_dir_sandbox:
-        sandbox = ToolExecutionSandbox(add_integers_tool.name, args, user_id=test_user.id)
+        sandbox = ToolExecutionSandbox(add_integers_tool.name, args, user=test_user)
         sandbox.run()
         mock_run_local_dir_sandbox.assert_called_once()
 
     # Run again to get actual response
-    sandbox = ToolExecutionSandbox(add_integers_tool.name, args, user_id=test_user.id)
+    sandbox = ToolExecutionSandbox(add_integers_tool.name, args, user=test_user)
     result = sandbox.run()
     assert result.func_return == args["x"] + args["y"]
 
@@ -297,7 +297,7 @@ def test_local_sandbox_default(mock_e2b_api_key_none, add_integers_tool, test_us
 def test_local_sandbox_stateful_tool(mock_e2b_api_key_none, clear_core_memory_tool, test_user, agent_state):
     args = {}
     # Run again to get actual response
-    sandbox = ToolExecutionSandbox(clear_core_memory_tool.name, args, user_id=test_user.id)
+    sandbox = ToolExecutionSandbox(clear_core_memory_tool.name, args, user=test_user)
     result = sandbox.run(agent_state=agent_state)
     assert result.agent_state.memory.get_block("human").value == ""
     assert result.agent_state.memory.get_block("persona").value == ""
@@ -306,7 +306,7 @@ def test_local_sandbox_stateful_tool(mock_e2b_api_key_none, clear_core_memory_to
 
 @pytest.mark.local_sandbox
 def test_local_sandbox_with_list_rv(mock_e2b_api_key_none, list_tool, test_user):
-    sandbox = ToolExecutionSandbox(list_tool.name, {}, user_id=test_user.id)
+    sandbox = ToolExecutionSandbox(list_tool.name, {}, user=test_user)
     result = sandbox.run()
     assert len(result.func_return) == 5
 
@@ -331,7 +331,7 @@ def test_local_sandbox_env(mock_e2b_api_key_none, get_env_tool, test_user):
     args = {}
 
     # Run the custom sandbox
-    sandbox = ToolExecutionSandbox(get_env_tool.name, args, user_id=test_user.id)
+    sandbox = ToolExecutionSandbox(get_env_tool.name, args, user=test_user)
     result = sandbox.run()
 
     assert long_random_string in result.func_return
@@ -349,7 +349,7 @@ def test_local_sandbox_e2e_composio_star_github(mock_e2b_api_key_none, check_com
         actor=test_user,
     )
 
-    result = ToolExecutionSandbox(composio_github_star_tool.name, {"owner": "letta-ai", "repo": "letta"}, user_id=test_user.id).run()
+    result = ToolExecutionSandbox(composio_github_star_tool.name, {"owner": "letta-ai", "repo": "letta"}, user=test_user).run()
     assert result.func_return["details"] == "Action executed successfully"
 
 
@@ -359,7 +359,7 @@ def test_local_sandbox_external_codebase(mock_e2b_api_key_none, custom_test_sand
     args = {"percentage": 10}
 
     # Run again to get actual response
-    sandbox = ToolExecutionSandbox(external_codebase_tool.name, args, user_id=test_user.id)
+    sandbox = ToolExecutionSandbox(external_codebase_tool.name, args, user=test_user)
     result = sandbox.run()
 
     # Assert that the function return is correct
@@ -371,14 +371,14 @@ def test_local_sandbox_external_codebase(mock_e2b_api_key_none, custom_test_sand
 def test_local_sandbox_with_venv_and_warnings_does_not_error(
     mock_e2b_api_key_none, custom_test_sandbox_config, get_warning_tool, test_user
 ):
-    sandbox = ToolExecutionSandbox(get_warning_tool.name, {}, user_id=test_user.id)
+    sandbox = ToolExecutionSandbox(get_warning_tool.name, {}, user=test_user)
     result = sandbox.run()
     assert result.func_return == "Hello World"
 
 
 @pytest.mark.e2b_sandbox
 def test_local_sandbox_with_venv_errors(mock_e2b_api_key_none, custom_test_sandbox_config, always_err_tool, test_user):
-    sandbox = ToolExecutionSandbox(always_err_tool.name, {}, user_id=test_user.id)
+    sandbox = ToolExecutionSandbox(always_err_tool.name, {}, user=test_user)
 
     # run the sandbox
     result = sandbox.run()
@@ -397,12 +397,12 @@ def test_e2b_sandbox_default(check_e2b_key_is_set, add_integers_tool, test_user)
 
     # Mock and assert correct pathway was invoked
     with patch.object(ToolExecutionSandbox, "run_e2b_sandbox") as mock_run_local_dir_sandbox:
-        sandbox = ToolExecutionSandbox(add_integers_tool.name, args, user_id=test_user.id)
+        sandbox = ToolExecutionSandbox(add_integers_tool.name, args, user=test_user)
         sandbox.run()
         mock_run_local_dir_sandbox.assert_called_once()
 
     # Run again to get actual response
-    sandbox = ToolExecutionSandbox(add_integers_tool.name, args, user_id=test_user.id)
+    sandbox = ToolExecutionSandbox(add_integers_tool.name, args, user=test_user)
     result = sandbox.run()
     assert int(result.func_return) == args["x"] + args["y"]
 
@@ -420,14 +420,14 @@ def test_e2b_sandbox_pip_installs(check_e2b_key_is_set, cowsay_tool, test_user):
         SandboxEnvironmentVariableCreate(key=key, value=long_random_string), sandbox_config_id=config.id, actor=test_user
     )
 
-    sandbox = ToolExecutionSandbox(cowsay_tool.name, {}, user_id=test_user.id)
+    sandbox = ToolExecutionSandbox(cowsay_tool.name, {}, user=test_user)
     result = sandbox.run()
     assert long_random_string in result.stdout[0]
 
 
 @pytest.mark.e2b_sandbox
 def test_e2b_sandbox_reuses_same_sandbox(check_e2b_key_is_set, list_tool, test_user):
-    sandbox = ToolExecutionSandbox(list_tool.name, {}, user_id=test_user.id)
+    sandbox = ToolExecutionSandbox(list_tool.name, {}, user=test_user)
 
     # Run the function once
     result = sandbox.run()
@@ -442,7 +442,7 @@ def test_e2b_sandbox_reuses_same_sandbox(check_e2b_key_is_set, list_tool, test_u
 
 @pytest.mark.e2b_sandbox
 def test_e2b_sandbox_stateful_tool(check_e2b_key_is_set, clear_core_memory_tool, test_user, agent_state):
-    sandbox = ToolExecutionSandbox(clear_core_memory_tool.name, {}, user_id=test_user.id)
+    sandbox = ToolExecutionSandbox(clear_core_memory_tool.name, {}, user=test_user)
 
     # run the sandbox
     result = sandbox.run(agent_state=agent_state)
@@ -458,7 +458,7 @@ def test_e2b_sandbox_inject_env_var_existing_sandbox(check_e2b_key_is_set, get_e
     config = manager.create_or_update_sandbox_config(config_create, test_user)
 
     # Run the custom sandbox once, assert nothing returns because missing env variable
-    sandbox = ToolExecutionSandbox(get_env_tool.name, {}, user_id=test_user.id, force_recreate=True)
+    sandbox = ToolExecutionSandbox(get_env_tool.name, {}, user=test_user, force_recreate=True)
     result = sandbox.run()
     # response should be None
     assert result.func_return is None
@@ -471,7 +471,7 @@ def test_e2b_sandbox_inject_env_var_existing_sandbox(check_e2b_key_is_set, get_e
     )
 
     # Assert that the environment variable gets injected correctly, even when the sandbox is NOT refreshed
-    sandbox = ToolExecutionSandbox(get_env_tool.name, {}, user_id=test_user.id)
+    sandbox = ToolExecutionSandbox(get_env_tool.name, {}, user=test_user)
     result = sandbox.run()
     assert long_random_string in result.func_return
 
@@ -487,7 +487,7 @@ def test_e2b_sandbox_config_change_force_recreates_sandbox(check_e2b_key_is_set,
     config = manager.create_or_update_sandbox_config(config_create, test_user)
 
     # Run the custom sandbox once, assert a failure gets returned because missing environment variable
-    sandbox = ToolExecutionSandbox(list_tool.name, {}, user_id=test_user.id)
+    sandbox = ToolExecutionSandbox(list_tool.name, {}, user=test_user)
     result = sandbox.run()
     assert len(result.func_return) == 5
     old_config_fingerprint = result.sandbox_config_fingerprint
@@ -497,7 +497,7 @@ def test_e2b_sandbox_config_change_force_recreates_sandbox(check_e2b_key_is_set,
     config = manager.update_sandbox_config(config.id, config_update, test_user)
 
     # Run again
-    result = ToolExecutionSandbox(list_tool.name, {}, user_id=test_user.id).run()
+    result = ToolExecutionSandbox(list_tool.name, {}, user=test_user).run()
     new_config_fingerprint = result.sandbox_config_fingerprint
     assert config.fingerprint() == new_config_fingerprint
 
@@ -507,7 +507,7 @@ def test_e2b_sandbox_config_change_force_recreates_sandbox(check_e2b_key_is_set,
 
 @pytest.mark.e2b_sandbox
 def test_e2b_sandbox_with_list_rv(check_e2b_key_is_set, list_tool, test_user):
-    sandbox = ToolExecutionSandbox(list_tool.name, {}, user_id=test_user.id)
+    sandbox = ToolExecutionSandbox(list_tool.name, {}, user=test_user)
     result = sandbox.run()
     assert len(result.func_return) == 5
 
@@ -524,7 +524,7 @@ def test_e2b_e2e_composio_star_github(check_e2b_key_is_set, check_composio_key_s
         actor=test_user,
     )
 
-    result = ToolExecutionSandbox(composio_github_star_tool.name, {"owner": "letta-ai", "repo": "letta"}, user_id=test_user.id).run()
+    result = ToolExecutionSandbox(composio_github_star_tool.name, {"owner": "letta-ai", "repo": "letta"}, user=test_user).run()
     assert result.func_return["details"] == "Action executed successfully"
 
 
@@ -541,7 +541,7 @@ def test_core_memory_replace_local(self, mock_e2b_api_key_none, core_memory_tool
         """Test successful replacement of content in core memory - local sandbox."""
         new_name = "Charles"
         args = {"label": "human", "old_content": "Chad", "new_content": new_name}
-        sandbox = ToolExecutionSandbox(core_memory_tools["core_memory_replace"].name, args, user_id=test_user.id)
+        sandbox = ToolExecutionSandbox(core_memory_tools["core_memory_replace"].name, args, user=test_user)
 
         result = sandbox.run(agent_state=agent_state)
         assert new_name in result.agent_state.memory.get_block("human").value
@@ -552,7 +552,7 @@ def test_core_memory_append_local(self, mock_e2b_api_key_none, core_memory_tools
         """Test successful appending of content to core memory - local sandbox."""
         append_text = "\nLikes coffee"
         args = {"label": "human", "content": append_text}
-        sandbox = ToolExecutionSandbox(core_memory_tools["core_memory_append"].name, args, user_id=test_user.id)
+        sandbox = ToolExecutionSandbox(core_memory_tools["core_memory_append"].name, args, user=test_user)
 
         result = sandbox.run(agent_state=agent_state)
         assert append_text in result.agent_state.memory.get_block("human").value
@@ -563,7 +563,7 @@ def test_core_memory_replace_error_local(self, mock_e2b_api_key_none, core_memor
         """Test error handling when trying to replace non-existent content - local sandbox."""
         nonexistent_name = "Alexander Wang"
         args = {"label": "human", "old_content": nonexistent_name, "new_content": "Charles"}
-        sandbox = ToolExecutionSandbox(core_memory_tools["core_memory_replace"].name, args, user_id=test_user.id)
+        sandbox = ToolExecutionSandbox(core_memory_tools["core_memory_replace"].name, args, user=test_user)
 
         result = sandbox.run(agent_state=agent_state)
         assert len(result.stderr) != 0
@@ -575,7 +575,7 @@ def test_core_memory_replace_e2b(self, check_e2b_key_is_set, core_memory_tools,
         """Test successful replacement of content in core memory - e2b sandbox."""
         new_name = "Charles"
         args = {"label": "human", "old_content": "Chad", "new_content": new_name}
-        sandbox = ToolExecutionSandbox(core_memory_tools["core_memory_replace"].name, args, user_id=test_user.id)
+        sandbox = ToolExecutionSandbox(core_memory_tools["core_memory_replace"].name, args, user=test_user)
 
         result = sandbox.run(agent_state=agent_state)
         assert new_name in result.agent_state.memory.get_block("human").value
@@ -586,7 +586,7 @@ def test_core_memory_append_e2b(self, check_e2b_key_is_set, core_memory_tools, t
         """Test successful appending of content to core memory - e2b sandbox."""
         append_text = "\nLikes coffee"
         args = {"label": "human", "content": append_text}
-        sandbox = ToolExecutionSandbox(core_memory_tools["core_memory_append"].name, args, user_id=test_user.id)
+        sandbox = ToolExecutionSandbox(core_memory_tools["core_memory_append"].name, args, user=test_user)
 
         result = sandbox.run(agent_state=agent_state)
         assert append_text in result.agent_state.memory.get_block("human").value
@@ -597,7 +597,7 @@ def test_core_memory_replace_error_e2b(self, check_e2b_key_is_set, core_memory_t
         """Test error handling when trying to replace non-existent content - e2b sandbox."""
         nonexistent_name = "Alexander Wang"
         args = {"label": "human", "old_content": nonexistent_name, "new_content": "Charles"}
-        sandbox = ToolExecutionSandbox(core_memory_tools["core_memory_replace"].name, args, user_id=test_user.id)
+        sandbox = ToolExecutionSandbox(core_memory_tools["core_memory_replace"].name, args, user=test_user)
 
         result = sandbox.run(agent_state=agent_state)
         assert len(result.stderr) != 0
diff --git a/tests/test_server.py b/tests/test_server.py
index 93159aa583..2003c68880 100644
--- a/tests/test_server.py
+++ b/tests/test_server.py
@@ -288,15 +288,16 @@ def org_id(server):
 
 
 @pytest.fixture(scope="module")
-def user_id(server, org_id):
-    # create user
+def user(server, org_id):
     user = server.user_manager.create_default_user()
-    print(f"Created user\n{user.id}")
+    yield user
+    server.user_manager.delete_user_by_id(user.id)
 
-    yield user.id
 
-    # cleanup
-    server.user_manager.delete_user_by_id(user.id)
+@pytest.fixture(scope="module")
+def user_id(server, user):
+    # create user
+    yield user.id
 
 
 @pytest.fixture(scope="module")
@@ -789,11 +790,11 @@ def ingest(message: str):
 '''
 
 
-def test_tool_run(server, mock_e2b_api_key_none, user_id, agent_id):
+def test_tool_run(server, mock_e2b_api_key_none, user, agent_id):
     """Test that the server can run tools"""
 
     result = server.run_tool_from_source(
-        user_id=user_id,
+        actor=user,
         tool_source=EXAMPLE_TOOL_SOURCE,
         tool_source_type="python",
         tool_args=json.dumps({"message": "Hello, world!"}),
@@ -806,7 +807,7 @@ def test_tool_run(server, mock_e2b_api_key_none, user_id, agent_id):
     assert not result.stderr
 
     result = server.run_tool_from_source(
-        user_id=user_id,
+        actor=user,
         tool_source=EXAMPLE_TOOL_SOURCE,
         tool_source_type="python",
         tool_args=json.dumps({"message": "Well well well"}),
@@ -819,7 +820,7 @@ def test_tool_run(server, mock_e2b_api_key_none, user_id, agent_id):
     assert not result.stderr
 
     result = server.run_tool_from_source(
-        user_id=user_id,
+        actor=user,
         tool_source=EXAMPLE_TOOL_SOURCE,
         tool_source_type="python",
         tool_args=json.dumps({"bad_arg": "oh no"}),
@@ -835,7 +836,7 @@ def test_tool_run(server, mock_e2b_api_key_none, user_id, agent_id):
 
     # Test that we can still pull the tool out by default (pulls that last tool in the source)
     result = server.run_tool_from_source(
-        user_id=user_id,
+        actor=user,
         tool_source=EXAMPLE_TOOL_SOURCE_WITH_DISTRACTOR,
         tool_source_type="python",
         tool_args=json.dumps({"message": "Well well well"}),
@@ -850,7 +851,7 @@ def test_tool_run(server, mock_e2b_api_key_none, user_id, agent_id):
 
     # Test that we can pull the tool out by name
     result = server.run_tool_from_source(
-        user_id=user_id,
+        actor=user,
         tool_source=EXAMPLE_TOOL_SOURCE_WITH_DISTRACTOR,
         tool_source_type="python",
         tool_args=json.dumps({"message": "Well well well"}),
@@ -865,7 +866,7 @@ def test_tool_run(server, mock_e2b_api_key_none, user_id, agent_id):
 
     # Test that we can pull a different tool out by name
     result = server.run_tool_from_source(
-        user_id=user_id,
+        actor=user,
         tool_source=EXAMPLE_TOOL_SOURCE_WITH_DISTRACTOR,
         tool_source_type="python",
         tool_args=json.dumps({}),