diff --git a/alembic/versions/4c6c9ef0387d_support_modal_sandbox_type.py b/alembic/versions/4c6c9ef0387d_support_modal_sandbox_type.py
new file mode 100644
index 00000000..652b3554
--- /dev/null
+++ b/alembic/versions/4c6c9ef0387d_support_modal_sandbox_type.py
@@ -0,0 +1,55 @@
+"""support modal sandbox type
+
+Revision ID: 4c6c9ef0387d
+Revises: 4537f0996495
+Create Date: 2025-07-29 15:10:08.996251
+
+"""
+
+from typing import Sequence, Union
+
+from sqlalchemy import text
+
+from alembic import op
+from letta.settings import DatabaseChoice, settings
+
+# revision identifiers, used by Alembic.
+revision: str = "4c6c9ef0387d"
+down_revision: Union[str, None] = "4537f0996495"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # SQLite just uses strings
+    if settings.database_engine == DatabaseChoice.POSTGRES:
+        op.execute("ALTER TYPE sandboxtype ADD VALUE 'MODAL' AFTER 'E2B'")
+
+
+def downgrade() -> None:
+    if settings.database_engine == DatabaseChoice.POSTGRES:
+        connection = op.get_bind()
+
+        data_conflicts = connection.execute(
+            text(
+                """
+            SELECT COUNT(*)
+            FROM sandbox_configs
+            WHERE "type" NOT IN ('E2B', 'LOCAL')
+        """
+            )
+        ).fetchone()
+        if data_conflicts[0]:
+            raise RuntimeError(
+                (
+                    "Cannot downgrade enum: Data conflicts are detected in sandbox_configs.sandboxtype.\n"
+                    "Please manually handle these records before handling the downgrades.\n"
+                    f"{data_conflicts} invalid sandboxtype values"
+                )
+            )
+
+        # Postgres does not support dropping enum values. Create a new enum and swap them.
+        op.execute("CREATE TYPE sandboxtype_old AS ENUM ('E2B', 'LOCAL')")
+        op.execute('ALTER TABLE sandbox_configs ALTER COLUMN "type" TYPE sandboxtype_old USING "type"::text::sandboxtype_old')
+        op.execute("DROP TYPE sandboxtype")
+        op.execute("ALTER TYPE sandboxtype_old RENAME to sandboxtype")
diff --git a/letta/agents/letta_agent_batch.py b/letta/agents/letta_agent_batch.py
index 3bca27f4..52ed9334 100644
--- a/letta/agents/letta_agent_batch.py
+++ b/letta/agents/letta_agent_batch.py
@@ -19,7 +19,7 @@ from letta.log import get_logger
 from letta.orm.enums import ToolType
 from letta.otel.tracing import log_event, trace_method
 from letta.schemas.agent import AgentState
-from letta.schemas.enums import AgentStepStatus, JobStatus, MessageStreamStatus, ProviderType
+from letta.schemas.enums import AgentStepStatus, JobStatus, MessageStreamStatus, ProviderType, SandboxType
 from letta.schemas.job import JobUpdate
 from letta.schemas.letta_message import LegacyLettaMessage, LettaMessage
 from letta.schemas.letta_message_content import OmittedReasoningContent, ReasoningContent, RedactedReasoningContent, TextContent
@@ -28,7 +28,7 @@ from letta.schemas.letta_response import LettaBatchResponse, LettaResponse
 from letta.schemas.llm_batch_job import AgentStepState, LLMBatchItem
 from letta.schemas.message import Message, MessageCreate
 from letta.schemas.openai.chat_completion_response import ToolCall as OpenAIToolCall
-from letta.schemas.sandbox_config import SandboxConfig, SandboxType
+from letta.schemas.sandbox_config import SandboxConfig
 from letta.schemas.tool_execution_result import ToolExecutionResult
 from letta.schemas.user import User
 from letta.server.rest_api.utils import create_heartbeat_system_message, create_letta_messages_from_llm_response
diff --git a/letta/helpers/tool_execution_helper.py b/letta/helpers/tool_execution_helper.py
index 1ec3f646..21f59062 100644
--- a/letta/helpers/tool_execution_helper.py
+++ b/letta/helpers/tool_execution_helper.py
@@ -1,17 +1,7 @@
 from collections import OrderedDict
 from typing import Any, Dict, Optional
 
-from letta.constants import COMPOSIO_ENTITY_ENV_VAR_KEY, PRE_EXECUTION_MESSAGE_ARG
-from letta.functions.ast_parsers import coerce_dict_args_by_annotations, get_function_annotations_from_source
-from letta.functions.composio_helpers import execute_composio_action, generate_composio_action_from_func_name
-from letta.helpers.composio_helpers import get_composio_api_key
-from letta.orm.enums import ToolType
-from letta.schemas.agent import AgentState
-from letta.schemas.sandbox_config import SandboxRunResult
-from letta.schemas.tool import Tool
-from letta.schemas.user import User
-from letta.services.tool_executor.tool_execution_sandbox import ToolExecutionSandbox
-from letta.utils import get_friendly_error_msg
+from letta.constants import PRE_EXECUTION_MESSAGE_ARG
 
 
 def enable_strict_mode(tool_schema: Dict[str, Any]) -> Dict[str, Any]:
@@ -44,6 +34,7 @@ def add_pre_execution_message(tool_schema: Dict[str, Any], description: Optional
 
     Args:
         tool_schema (Dict[str, Any]): The original tool schema.
+        description (Optional[str]): Description of the tool schema. Defaults to None.
 
     Returns:
         Dict[str, Any]: A new tool schema with the `pre_execution_message` field added at the beginning.
@@ -117,57 +108,3 @@ def remove_request_heartbeat(tool_schema: Dict[str, Any]) -> Dict[str, Any]:
         schema["parameters"] = {**parameters, "properties": properties, "required": required}
 
     return schema
-
-
-# TODO: Deprecate the `execute_external_tool` function on the agent body
-def execute_external_tool(
-    agent_state: AgentState,
-    function_name: str,
-    function_args: dict,
-    target_letta_tool: Tool,
-    actor: User,
-    allow_agent_state_modifications: bool = False,
-) -> tuple[Any, Optional[SandboxRunResult]]:
-    # TODO: need to have an AgentState object that actually has full access to the block data
-    # this is because the sandbox tools need to be able to access block.value to edit this data
-    try:
-        if target_letta_tool.tool_type == ToolType.EXTERNAL_COMPOSIO:
-            action_name = generate_composio_action_from_func_name(target_letta_tool.name)
-            # Get entity ID from the agent_state
-            entity_id = None
-            for env_var in agent_state.tool_exec_environment_variables:
-                if env_var.key == COMPOSIO_ENTITY_ENV_VAR_KEY:
-                    entity_id = env_var.value
-            # Get composio_api_key
-            composio_api_key = get_composio_api_key(actor=actor)
-            function_response = execute_composio_action(
-                action_name=action_name, args=function_args, api_key=composio_api_key, entity_id=entity_id
-            )
-            return function_response, None
-        elif target_letta_tool.tool_type == ToolType.CUSTOM:
-            # Parse the source code to extract function annotations
-            annotations = get_function_annotations_from_source(target_letta_tool.source_code, function_name)
-            # Coerce the function arguments to the correct types based on the annotations
-            function_args = coerce_dict_args_by_annotations(function_args, annotations)
-
-            # execute tool in a sandbox
-            # TODO: allow agent_state to specify which sandbox to execute tools in
-            # TODO: This is only temporary, can remove after we publish a pip package with this object
-            if allow_agent_state_modifications:
-                agent_state_copy = agent_state.__deepcopy__()
-                agent_state_copy.tools = []
-                agent_state_copy.tool_rules = []
-            else:
-                agent_state_copy = None
-
-            tool_execution_result = ToolExecutionSandbox(function_name, function_args, actor).run(agent_state=agent_state_copy)
-            function_response, updated_agent_state = tool_execution_result.func_return, tool_execution_result.agent_state
-            # TODO: Bring this back
-            # if allow_agent_state_modifications and updated_agent_state is not None:
-            #     self.update_memory_if_changed(updated_agent_state.memory)
-            return function_response, tool_execution_result
-    except Exception as e:
-        # Need to catch error here, or else trunction wont happen
-        # TODO: modify to function execution error
-        function_response = get_friendly_error_msg(function_name=function_name, exception_name=type(e).__name__, exception_message=str(e))
-        return function_response, None
diff --git a/letta/orm/__all__.py b/letta/orm/__all__.py
deleted file mode 100644
index ed823219..00000000
--- a/letta/orm/__all__.py
+++ /dev/null
@@ -1,15 +0,0 @@
-"""__all__ acts as manual import management to avoid collisions and circular imports."""
-
-# from letta.orm.agent import Agent
-# from letta.orm.users_agents import UsersAgents
-# from letta.orm.blocks_agents import BlocksAgents
-# from letta.orm.token import Token
-# from letta.orm.source import Source
-# from letta.orm.document import Document
-# from letta.orm.passage import Passage
-# from letta.orm.memory_templates import MemoryTemplate, HumanMemoryTemplate, PersonaMemoryTemplate
-# from letta.orm.sources_agents import SourcesAgents
-# from letta.orm.tools_agents import ToolsAgents
-# from letta.orm.job import Job
-# from letta.orm.block import Block
-# from letta.orm.message import Message
diff --git a/letta/orm/enums.py b/letta/orm/enums.py
index c885780b..81bfb515 100644
--- a/letta/orm/enums.py
+++ b/letta/orm/enums.py
@@ -17,6 +17,5 @@ class ToolType(str, Enum):
     LETTA_BUILTIN = "letta_builtin"
     LETTA_FILES_CORE = "letta_files_core"
     EXTERNAL_COMPOSIO = "external_composio"
-    EXTERNAL_LANGCHAIN = "external_langchain"
     # TODO is "external" the right name here? Since as of now, MCP is local / doesn't support remote?
     EXTERNAL_MCP = "external_mcp"
diff --git a/letta/orm/sandbox_config.py b/letta/orm/sandbox_config.py
index 44fad192..b8d6ba57 100644
--- a/letta/orm/sandbox_config.py
+++ b/letta/orm/sandbox_config.py
@@ -8,9 +8,9 @@ from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from letta.orm.mixins import AgentMixin, OrganizationMixin, SandboxConfigMixin
 from letta.orm.sqlalchemy_base import SqlalchemyBase
+from letta.schemas.enums import SandboxType
 from letta.schemas.environment_variables import SandboxEnvironmentVariable as PydanticSandboxEnvironmentVariable
 from letta.schemas.sandbox_config import SandboxConfig as PydanticSandboxConfig
-from letta.schemas.sandbox_config import SandboxType
 
 if TYPE_CHECKING:
     from letta.orm.agent import Agent
diff --git a/letta/schemas/enums.py b/letta/schemas/enums.py
index fba439cb..a0000fcc 100644
--- a/letta/schemas/enums.py
+++ b/letta/schemas/enums.py
@@ -153,3 +153,9 @@ class DuplicateFileHandling(str, Enum):
     SKIP = "skip"  # skip files with duplicate names
     ERROR = "error"  # error when duplicate names are encountered
     SUFFIX = "suffix"  # add numeric suffix to make names unique (default behavior)
+
+
+class SandboxType(str, Enum):
+    E2B = "e2b"
+    MODAL = "modal"
+    LOCAL = "local"
diff --git a/letta/schemas/sandbox_config.py b/letta/schemas/sandbox_config.py
index f3b90d8e..73d13638 100644
--- a/letta/schemas/sandbox_config.py
+++ b/letta/schemas/sandbox_config.py
@@ -1,21 +1,17 @@
 import hashlib
 import json
-from enum import Enum
 from typing import Any, Dict, List, Literal, Optional, Union
 
 from pydantic import BaseModel, Field, model_validator
 
 from letta.constants import LETTA_TOOL_EXECUTION_DIR
 from letta.schemas.agent import AgentState
+from letta.schemas.enums import SandboxType
 from letta.schemas.letta_base import LettaBase, OrmMetadataBase
 from letta.schemas.pip_requirement import PipRequirement
 from letta.settings import tool_settings
 
-
 # Sandbox Config
-class SandboxType(str, Enum):
-    E2B = "e2b"
-    LOCAL = "local"
 
 
 class SandboxRunResult(BaseModel):
@@ -83,6 +79,15 @@ class E2BSandboxConfig(BaseModel):
         return data
 
 
+class ModalSandboxConfig(BaseModel):
+    timeout: int = Field(5 * 60, description="Time limit for the sandbox (in seconds).")
+    pip_requirements: Optional[List[str]] = Field(None, description="A list of pip packages to install in the Modal sandbox")
+
+    @property
+    def type(self) -> "SandboxType":
+        return SandboxType.MODAL
+
+
 class SandboxConfigBase(OrmMetadataBase):
     __id_prefix__ = "sandbox"
 
@@ -99,6 +104,9 @@ class SandboxConfig(SandboxConfigBase):
     def get_local_config(self) -> LocalSandboxConfig:
         return LocalSandboxConfig(**self.config)
 
+    def get_modal_config(self) -> ModalSandboxConfig:
+        return ModalSandboxConfig(**self.config)
+
     def fingerprint(self) -> str:
         # Only take into account type, org_id, and the config items
         # Canonicalize input data into JSON with sorted keys
@@ -120,10 +128,12 @@ class SandboxConfig(SandboxConfigBase):
 
 
 class SandboxConfigCreate(LettaBase):
-    config: Union[LocalSandboxConfig, E2BSandboxConfig] = Field(..., description="The configuration for the sandbox.")
+    config: Union[LocalSandboxConfig, E2BSandboxConfig, ModalSandboxConfig] = Field(..., description="The configuration for the sandbox.")
 
 
 class SandboxConfigUpdate(LettaBase):
     """Pydantic model for updating SandboxConfig fields."""
 
-    config: Union[LocalSandboxConfig, E2BSandboxConfig] = Field(None, description="The JSON configuration data for the sandbox.")
+    config: Union[LocalSandboxConfig, E2BSandboxConfig, ModalSandboxConfig] = Field(
+        None, description="The JSON configuration data for the sandbox."
+    )
diff --git a/letta/server/rest_api/routers/v1/sandbox_configs.py b/letta/server/rest_api/routers/v1/sandbox_configs.py
index d82e9fff..c72c35ad 100644
--- a/letta/server/rest_api/routers/v1/sandbox_configs.py
+++ b/letta/server/rest_api/routers/v1/sandbox_configs.py
@@ -5,11 +5,12 @@ from typing import List, Optional
 from fastapi import APIRouter, Depends, HTTPException, Query
 
 from letta.log import get_logger
+from letta.schemas.enums import SandboxType
 from letta.schemas.environment_variables import SandboxEnvironmentVariable as PydanticEnvVar
 from letta.schemas.environment_variables import SandboxEnvironmentVariableCreate, SandboxEnvironmentVariableUpdate
 from letta.schemas.sandbox_config import LocalSandboxConfig
 from letta.schemas.sandbox_config import SandboxConfig as PydanticSandboxConfig
-from letta.schemas.sandbox_config import SandboxConfigCreate, SandboxConfigUpdate, SandboxType
+from letta.schemas.sandbox_config import SandboxConfigCreate, SandboxConfigUpdate
 from letta.server.rest_api.utils import get_letta_server, get_user_id
 from letta.server.server import SyncServer
 from letta.services.helpers.tool_execution_helper import create_venv_for_local_sandbox, install_pip_requirements_for_sandbox
diff --git a/letta/server/server.py b/letta/server/server.py
index dcf604b0..f127b1dd 100644
--- a/letta/server/server.py
+++ b/letta/server/server.py
@@ -40,7 +40,7 @@ from letta.schemas.block import Block, BlockUpdate, CreateBlock
 from letta.schemas.embedding_config import EmbeddingConfig
 
 # openai schemas
-from letta.schemas.enums import JobStatus, MessageStreamStatus, ProviderCategory, ProviderType
+from letta.schemas.enums import JobStatus, MessageStreamStatus, ProviderCategory, ProviderType, SandboxType
 from letta.schemas.environment_variables import SandboxEnvironmentVariableCreate
 from letta.schemas.group import GroupCreate, ManagerType, SleeptimeManager, VoiceSleeptimeManager
 from letta.schemas.job import Job, JobUpdate
@@ -69,7 +69,7 @@ from letta.schemas.providers import (
     TogetherProvider,
     XAIProvider,
 )
-from letta.schemas.sandbox_config import LocalSandboxConfig, SandboxConfigCreate, SandboxType
+from letta.schemas.sandbox_config import LocalSandboxConfig, SandboxConfigCreate
 from letta.schemas.source import Source
 from letta.schemas.tool import Tool
 from letta.schemas.usage import LettaUsageStatistics
diff --git a/letta/services/sandbox_config_manager.py b/letta/services/sandbox_config_manager.py
index d9a8bffb..5289ede9 100644
--- a/letta/services/sandbox_config_manager.py
+++ b/letta/services/sandbox_config_manager.py
@@ -6,11 +6,12 @@ from letta.orm.errors import NoResultFound
 from letta.orm.sandbox_config import SandboxConfig as SandboxConfigModel
 from letta.orm.sandbox_config import SandboxEnvironmentVariable as SandboxEnvVarModel
 from letta.otel.tracing import trace_method
+from letta.schemas.enums import SandboxType
 from letta.schemas.environment_variables import SandboxEnvironmentVariable as PydanticEnvVar
 from letta.schemas.environment_variables import SandboxEnvironmentVariableCreate, SandboxEnvironmentVariableUpdate
 from letta.schemas.sandbox_config import LocalSandboxConfig
 from letta.schemas.sandbox_config import SandboxConfig as PydanticSandboxConfig
-from letta.schemas.sandbox_config import SandboxConfigCreate, SandboxConfigUpdate, SandboxType
+from letta.schemas.sandbox_config import SandboxConfigCreate, SandboxConfigUpdate
 from letta.schemas.user import User as PydanticUser
 from letta.server.db import db_registry
 from letta.utils import enforce_types, printd
@@ -493,10 +494,7 @@ class SandboxConfigManager:
         self, sandbox_config_id: str, actor: PydanticUser, after: Optional[str] = None, limit: Optional[int] = 50
     ) -> Dict[str, str]:
         env_vars = await self.list_sandbox_env_vars_async(sandbox_config_id, actor, after, limit)
-        result = {}
-        for env_var in env_vars:
-            result[env_var.key] = env_var.value
-        return result
+        return {env_var.key: env_var.value for env_var in env_vars}
 
     @enforce_types
     @trace_method
diff --git a/letta/services/tool_executor/tool_executor.py b/letta/services/tool_executor/sandbox_tool_executor.py
similarity index 88%
rename from letta/services/tool_executor/tool_executor.py
rename to letta/services/tool_executor/sandbox_tool_executor.py
index 530e5db0..d0153dd2 100644
--- a/letta/services/tool_executor/tool_executor.py
+++ b/letta/services/tool_executor/sandbox_tool_executor.py
@@ -5,6 +5,7 @@ from letta.functions.ast_parsers import coerce_dict_args_by_annotations, get_fun
 from letta.log import get_logger
 from letta.otel.tracing import trace_method
 from letta.schemas.agent import AgentState
+from letta.schemas.enums import SandboxType
 from letta.schemas.sandbox_config import SandboxConfig
 from letta.schemas.tool import Tool
 from letta.schemas.tool_execution_result import ToolExecutionResult
@@ -12,6 +13,7 @@ from letta.schemas.user import User
 from letta.services.agent_manager import AgentManager
 from letta.services.tool_executor.tool_executor_base import ToolExecutor
 from letta.services.tool_sandbox.local_sandbox import AsyncToolSandboxLocal
+from letta.services.tool_sandbox.modal_sandbox import AsyncToolSandboxModal
 from letta.settings import tool_settings
 from letta.types import JsonDict
 from letta.utils import get_friendly_error_msg
@@ -50,10 +52,14 @@ class SandboxToolExecutor(ToolExecutor):
             agent_state_copy = self._create_agent_state_copy(agent_state) if agent_state else None
 
             # Execute in sandbox depending on API key
-            if tool_settings.e2b_api_key:
+            if tool_settings.sandbox_type == SandboxType.E2B:
                 sandbox = AsyncToolSandboxE2B(
                     function_name, function_args, actor, tool_object=tool, sandbox_config=sandbox_config, sandbox_env_vars=sandbox_env_vars
                 )
+            elif tool_settings.sandbox_type == SandboxType.MODAL:
+                sandbox = AsyncToolSandboxModal(
+                    function_name, function_args, actor, tool_object=tool, sandbox_config=sandbox_config, sandbox_env_vars=sandbox_env_vars
+                )
             else:
                 sandbox = AsyncToolSandboxLocal(
                     function_name, function_args, actor, tool_object=tool, sandbox_config=sandbox_config, sandbox_env_vars=sandbox_env_vars
@@ -61,6 +67,9 @@ class SandboxToolExecutor(ToolExecutor):
 
             tool_execution_result = await sandbox.run(agent_state=agent_state_copy)
 
+            log_lines = (tool_execution_result.stdout or []) + (tool_execution_result.stderr or [])
+            logger.debug("Tool execution log: %s", "\n".join(log_lines))
+
             # Verify memory integrity
             if agent_state:
                 new_memory_str = await agent_state.memory.compile_async()
diff --git a/letta/services/tool_executor/tool_execution_manager.py b/letta/services/tool_executor/tool_execution_manager.py
index f4f94ae5..eca264a9 100644
--- a/letta/services/tool_executor/tool_execution_manager.py
+++ b/letta/services/tool_executor/tool_execution_manager.py
@@ -24,7 +24,7 @@ from letta.services.tool_executor.core_tool_executor import LettaCoreToolExecuto
 from letta.services.tool_executor.files_tool_executor import LettaFileToolExecutor
 from letta.services.tool_executor.mcp_tool_executor import ExternalMCPToolExecutor
 from letta.services.tool_executor.multi_agent_tool_executor import LettaMultiAgentToolExecutor
-from letta.services.tool_executor.tool_executor import SandboxToolExecutor
+from letta.services.tool_executor.sandbox_tool_executor import SandboxToolExecutor
 from letta.services.tool_executor.tool_executor_base import ToolExecutor
 from letta.utils import get_friendly_error_msg
 
diff --git a/letta/services/tool_executor/tool_execution_sandbox.py b/letta/services/tool_executor/tool_execution_sandbox.py
index e41089ea..f487df47 100644
--- a/letta/services/tool_executor/tool_execution_sandbox.py
+++ b/letta/services/tool_executor/tool_execution_sandbox.py
@@ -13,7 +13,8 @@ from letta.functions.helpers import generate_model_from_args_json_schema
 from letta.log import get_logger
 from letta.otel.tracing import log_event, trace_method
 from letta.schemas.agent import AgentState
-from letta.schemas.sandbox_config import SandboxConfig, SandboxType
+from letta.schemas.enums import SandboxType
+from letta.schemas.sandbox_config import SandboxConfig
 from letta.schemas.tool import Tool
 from letta.schemas.tool_execution_result import ToolExecutionResult
 from letta.schemas.user import User
diff --git a/letta/services/tool_manager.py b/letta/services/tool_manager.py
index 29d2723a..5071f79c 100644
--- a/letta/services/tool_manager.py
+++ b/letta/services/tool_manager.py
@@ -143,13 +143,6 @@ class ToolManager:
             PydanticTool(tool_type=ToolType.EXTERNAL_COMPOSIO, name=tool_create.json_schema["name"], **tool_create.model_dump()), actor
         )
 
-    @enforce_types
-    @trace_method
-    def create_or_update_langchain_tool(self, tool_create: ToolCreate, actor: PydanticUser) -> PydanticTool:
-        return self.create_or_update_tool(
-            PydanticTool(tool_type=ToolType.EXTERNAL_LANGCHAIN, name=tool_create.json_schema["name"], **tool_create.model_dump()), actor
-        )
-
     @enforce_types
     @trace_method
     def create_tool(self, pydantic_tool: PydanticTool, actor: PydanticUser) -> PydanticTool:
diff --git a/letta/services/tool_sandbox/base.py b/letta/services/tool_sandbox/base.py
index 68e4d109..fb953772 100644
--- a/letta/services/tool_sandbox/base.py
+++ b/letta/services/tool_sandbox/base.py
@@ -1,3 +1,4 @@
+import os
 import pickle
 import uuid
 from abc import ABC, abstractmethod
@@ -188,5 +189,20 @@ class AsyncToolSandboxBase(ABC):
         """
         return False  # Default to False for local execution
 
-    def _update_env_vars(self):
-        pass  # TODO
+    async def _gather_env_vars(self, agent_state: AgentState | None, additional_env_vars: dict[str, str], sbx_id: str, is_local: bool):
+        env = os.environ.copy() if is_local else {}
+        if self.provided_sandbox_env_vars:
+            env.update(self.provided_sandbox_env_vars)
+        else:
+            env_vars = await self.sandbox_config_manager.get_sandbox_env_vars_as_dict_async(
+                sandbox_config_id=sbx_id, actor=self.user, limit=None
+            )
+            env.update(env_vars)
+
+        if agent_state:
+            env.update(agent_state.get_agent_env_vars_as_dict())
+
+        if additional_env_vars:
+            env.update(additional_env_vars)
+
+        return env
diff --git a/letta/services/tool_sandbox/e2b_sandbox.py b/letta/services/tool_sandbox/e2b_sandbox.py
index bdc65e5c..dc1e92f5 100644
--- a/letta/services/tool_sandbox/e2b_sandbox.py
+++ b/letta/services/tool_sandbox/e2b_sandbox.py
@@ -6,7 +6,8 @@ from e2b_code_interpreter import AsyncSandbox
 from letta.log import get_logger
 from letta.otel.tracing import log_event, trace_method
 from letta.schemas.agent import AgentState
-from letta.schemas.sandbox_config import SandboxConfig, SandboxType
+from letta.schemas.enums import SandboxType
+from letta.schemas.sandbox_config import SandboxConfig
 from letta.schemas.tool import Tool
 from letta.schemas.tool_execution_result import ToolExecutionResult
 from letta.services.helpers.tool_parser_helper import parse_stdout_best_effort
@@ -41,22 +42,6 @@ class AsyncToolSandboxE2B(AsyncToolSandboxBase):
         self,
         agent_state: Optional[AgentState] = None,
         additional_env_vars: Optional[Dict] = None,
-    ) -> ToolExecutionResult:
-        """
-        Run the tool in a sandbox environment asynchronously,
-        *always* using a subprocess for execution.
-        """
-        result = await self.run_e2b_sandbox(agent_state=agent_state, additional_env_vars=additional_env_vars)
-
-        # Simple console logging for demonstration
-        for log_line in (result.stdout or []) + (result.stderr or []):
-            print(f"Tool execution log: {log_line}")
-
-        return result
-
-    @trace_method
-    async def run_e2b_sandbox(
-        self, agent_state: Optional[AgentState] = None, additional_env_vars: Optional[Dict] = None
     ) -> ToolExecutionResult:
         if self.provided_sandbox_config:
             sbx_config = self.provided_sandbox_config
@@ -76,30 +61,15 @@ class AsyncToolSandboxE2B(AsyncToolSandboxBase):
         # await sbx.set_timeout(sbx_config.get_e2b_config().timeout)
 
         # Get environment variables for the sandbox
-        # TODO: We set limit to 100 here, but maybe we want it uncapped? Realistically this should be fine.
-        env_vars = {}
-        if self.provided_sandbox_env_vars:
-            env_vars.update(self.provided_sandbox_env_vars)
-        else:
-            db_env_vars = await self.sandbox_config_manager.get_sandbox_env_vars_as_dict_async(
-                sandbox_config_id=sbx_config.id, actor=self.user, limit=100
-            )
-            env_vars.update(db_env_vars)
-        # Get environment variables for this agent specifically
-        if agent_state:
-            env_vars.update(agent_state.get_agent_env_vars_as_dict())
-
-        # Finally, get any that are passed explicitly into the `run` function call
-        if additional_env_vars:
-            env_vars.update(additional_env_vars)
+        envs = await self._gather_env_vars(agent_state, additional_env_vars, sbx_config.id, is_local=False)
         code = await self.generate_execution_script(agent_state=agent_state)
 
         try:
             log_event(
                 "e2b_execution_started",
-                {"tool": self.tool_name, "sandbox_id": e2b_sandbox.sandbox_id, "code": code, "env_vars": env_vars},
+                {"tool": self.tool_name, "sandbox_id": e2b_sandbox.sandbox_id, "code": code, "env_vars": envs},
             )
-            execution = await e2b_sandbox.run_code(code, envs=env_vars)
+            execution = await e2b_sandbox.run_code(code, envs=envs)
 
             if execution.results:
                 func_return, agent_state = parse_stdout_best_effort(execution.results[0].text)
diff --git a/letta/services/tool_sandbox/local_sandbox.py b/letta/services/tool_sandbox/local_sandbox.py
index 8f2b2871..696be7f5 100644
--- a/letta/services/tool_sandbox/local_sandbox.py
+++ b/letta/services/tool_sandbox/local_sandbox.py
@@ -11,7 +11,8 @@ from pydantic.config import JsonDict
 from letta.log import get_logger
 from letta.otel.tracing import log_event, trace_method
 from letta.schemas.agent import AgentState
-from letta.schemas.sandbox_config import SandboxConfig, SandboxType
+from letta.schemas.enums import SandboxType
+from letta.schemas.sandbox_config import SandboxConfig
 from letta.schemas.tool import Tool
 from letta.schemas.tool_execution_result import ToolExecutionResult
 from letta.services.helpers.tool_execution_helper import (
@@ -44,34 +45,16 @@ class AsyncToolSandboxLocal(AsyncToolSandboxBase):
         super().__init__(tool_name, args, user, tool_object, sandbox_config=sandbox_config, sandbox_env_vars=sandbox_env_vars)
         self.force_recreate_venv = force_recreate_venv
 
+    @trace_method
     async def run(
         self,
         agent_state: Optional[AgentState] = None,
         additional_env_vars: Optional[Dict] = None,
     ) -> ToolExecutionResult:
         """
-        Run the tool in a sandbox environment asynchronously,
-        *always* using a subprocess for execution.
+        Run the tool in a local sandbox environment asynchronously.
+        Uses a subprocess for multi-core parallelism.
         """
-        result = await self.run_local_dir_sandbox(agent_state=agent_state, additional_env_vars=additional_env_vars)
-
-        # Simple console logging for demonstration
-        for log_line in (result.stdout or []) + (result.stderr or []):
-            print(f"Tool execution log: {log_line}")
-
-        return result
-
-    @trace_method
-    async def run_local_dir_sandbox(
-        self,
-        agent_state: Optional[AgentState],
-        additional_env_vars: Optional[Dict],
-    ) -> ToolExecutionResult:
-        """
-        Unified asynchronous method to run the tool in a local sandbox environment,
-        always via subprocess for multi-core parallelism.
-        """
-        # Get sandbox configuration
         if self.provided_sandbox_config:
             sbx_config = self.provided_sandbox_config
         else:
diff --git a/letta/services/tool_sandbox/modal_sandbox.py b/letta/services/tool_sandbox/modal_sandbox.py
new file mode 100644
index 00000000..a1ed216a
--- /dev/null
+++ b/letta/services/tool_sandbox/modal_sandbox.py
@@ -0,0 +1,205 @@
+from typing import Any, Dict, Optional
+
+import modal
+
+from letta.log import get_logger
+from letta.otel.tracing import log_event, trace_method
+from letta.schemas.agent import AgentState
+from letta.schemas.enums import SandboxType
+from letta.schemas.sandbox_config import SandboxConfig
+from letta.schemas.tool import Tool
+from letta.schemas.tool_execution_result import ToolExecutionResult
+from letta.services.helpers.tool_parser_helper import parse_stdout_best_effort
+from letta.services.tool_sandbox.base import AsyncToolSandboxBase
+from letta.settings import tool_settings
+from letta.types import JsonDict
+from letta.utils import get_friendly_error_msg
+
+logger = get_logger(__name__)
+
+
+class AsyncToolSandboxModal(AsyncToolSandboxBase):
+    def __init__(
+        self,
+        tool_name: str,
+        args: JsonDict,
+        user,
+        tool_object: Tool | None = None,
+        sandbox_config: SandboxConfig | None = None,
+        sandbox_env_vars: dict[str, Any] | None = None,
+    ):
+        super().__init__(tool_name, args, user, tool_object, sandbox_config=sandbox_config, sandbox_env_vars=sandbox_env_vars)
+
+        if not tool_settings.modal_api_key:
+            raise ValueError("Modal API key is required but not set in tool_settings.modal_api_key")
+
+        # Create a unique app name based on tool and config
+        self._app_name = self._generate_app_name()
+
+    def _generate_app_name(self) -> str:
+        """Generate a unique app name based on tool and configuration. Created based on tool name and org"""
+        return f"{self.user.organization_id}-{self.tool_name}"
+
+    async def _fetch_or_create_modal_app(self, sbx_config: SandboxConfig, env_vars: Dict[str, str]) -> modal.App:
+        """Create a Modal app with the tool function registered."""
+        app = await modal.App.lookup.aio(self._app_name)
+        modal_config = sbx_config.get_modal_config()
+
+        # Get the base image with dependencies
+        image = self._get_modal_image(sbx_config)
+
+        # Decorator for the tool, note information on running untrusted code: https://modal.com/docs/guide/restricted-access
+        # The `@app.function` decorator must apply to functions in global scope, unless `serialized=True` is set.
+        @app.function(image=image, timeout=modal_config.timeout, restrict_modal_access=True, max_inputs=1, serialized=True)
+        def execute_tool_with_script(execution_script: str, environment_vars: dict[str, str]):
+            """Execute the generated tool script in Modal sandbox."""
+            import os
+
+            # Note: We pass environment variables directly instead of relying on Modal secrets
+            # This is more flexible and doesn't require pre-configured secrets
+            for key, value in environment_vars.items():
+                os.environ[key] = str(value)
+
+            exec_globals = {}
+            exec(execution_script, exec_globals)
+
+        # Store the function reference in the app for later use
+        app.remote_executor = execute_tool_with_script
+        return app
+
+    @trace_method
+    async def run(
+        self,
+        agent_state: Optional[AgentState] = None,
+        additional_env_vars: Optional[Dict] = None,
+    ) -> ToolExecutionResult:
+        if self.provided_sandbox_config:
+            sbx_config = self.provided_sandbox_config
+        else:
+            sbx_config = await self.sandbox_config_manager.get_or_create_default_sandbox_config_async(
+                sandbox_type=SandboxType.MODAL, actor=self.user
+            )
+
+        envs = await self._gather_env_vars(agent_state, additional_env_vars or {}, sbx_config.id, is_local=False)
+
+        # Generate execution script (this includes the tool source code and execution logic)
+        execution_script = await self.generate_execution_script(agent_state=agent_state)
+
+        try:
+            log_event(
+                "modal_execution_started",
+                {"tool": self.tool_name, "app_name": self._app_name, "env_vars": list(envs)},
+            )
+
+            # Create Modal app with the tool function registered
+            app = await self._fetch_or_create_modal_app(sbx_config, envs)
+
+            # Execute the tool remotely
+            with app.run():
+                result = app.remote_executor.remote(execution_script, envs)
+
+            # Process the result
+            if result["error"]:
+                logger.error(
+                    f"Executing tool {self.tool_name} raised a {result['error']['name']} with message: \n{result['error']['value']}"
+                )
+                logger.error(f"Traceback from Modal sandbox: \n{result['error']['traceback']}")
+                func_return = get_friendly_error_msg(
+                    function_name=self.tool_name, exception_name=result["error"]["name"], exception_message=result["error"]["value"]
+                )
+                log_event(
+                    "modal_execution_failed",
+                    {
+                        "tool": self.tool_name,
+                        "app_name": self._app_name,
+                        "error_type": result["error"]["name"],
+                        "error_message": result["error"]["value"],
+                        "func_return": func_return,
+                    },
+                )
+                # Parse the result from stdout even if there was an error
+                # (in case the function returned something before failing)
+                agent_state = None  # Initialize agent_state
+                try:
+                    func_return_parsed, agent_state_parsed = parse_stdout_best_effort(result["stdout"])
+                    if func_return_parsed is not None:
+                        func_return = func_return_parsed
+                        agent_state = agent_state_parsed
+                except Exception:
+                    # If parsing fails, keep the error message
+                    pass
+            else:
+                func_return, agent_state = parse_stdout_best_effort(result["stdout"])
+                log_event(
+                    "modal_execution_succeeded",
+                    {
+                        "tool": self.tool_name,
+                        "app_name": self._app_name,
+                        "func_return": func_return,
+                    },
+                )
+
+            return ToolExecutionResult(
+                func_return=func_return,
+                agent_state=agent_state,
+                stdout=[result["stdout"]] if result["stdout"] else [],
+                stderr=[result["stderr"]] if result["stderr"] else [],
+                status="error" if result["error"] else "success",
+                sandbox_config_fingerprint=sbx_config.fingerprint(),
+            )
+
+        except Exception as e:
+            logger.error(f"Modal execution for tool {self.tool_name} encountered an error: {e}")
+            func_return = get_friendly_error_msg(
+                function_name=self.tool_name,
+                exception_name=type(e).__name__,
+                exception_message=str(e),
+            )
+            log_event(
+                "modal_execution_error",
+                {
+                    "tool": self.tool_name,
+                    "app_name": self._app_name,
+                    "error": str(e),
+                    "func_return": func_return,
+                },
+            )
+            return ToolExecutionResult(
+                func_return=func_return,
+                agent_state=None,
+                stdout=[],
+                stderr=[str(e)],
+                status="error",
+                sandbox_config_fingerprint=sbx_config.fingerprint(),
+            )
+
+    def _get_modal_image(self, sbx_config: SandboxConfig) -> modal.Image:
+        """Get Modal image with required public python dependencies.
+
+        Caching and rebuilding is handled in a cascading manner
+        https://modal.com/docs/guide/images#image-caching-and-rebuilds
+        """
+        image = modal.Image.debian_slim(python_version="3.12")
+
+        all_requirements = ["letta"]
+
+        # Add sandbox-specific pip requirements
+        modal_configs = sbx_config.get_modal_config()
+        if modal_configs.pip_requirements:
+            all_requirements.extend([str(req) for req in modal_configs.pip_requirements])
+
+        # Add tool-specific pip requirements
+        if self.tool and self.tool.pip_requirements:
+            all_requirements.extend([str(req) for req in self.tool.pip_requirements])
+
+        if all_requirements:
+            image = image.pip_install(*all_requirements)
+
+        return image
+
+    def use_top_level_await(self) -> bool:
+        """
+        Modal functions don't have an active event loop by default,
+        so we should use asyncio.run() like local execution.
+        """
+        return False
diff --git a/letta/settings.py b/letta/settings.py
index df842d7e..f951c88d 100644
--- a/letta/settings.py
+++ b/letta/settings.py
@@ -7,21 +7,22 @@ from pydantic import AliasChoices, Field
 from pydantic_settings import BaseSettings, SettingsConfigDict
 
 from letta.local_llm.constants import DEFAULT_WRAPPER_NAME, INNER_THOUGHTS_KWARG
+from letta.schemas.enums import SandboxType
 from letta.services.summarizer.enums import SummarizationMode
 
 
 class ToolSettings(BaseSettings):
-    composio_api_key: Optional[str] = None
+    composio_api_key: str | None = Field(default=None, description="API key for Composio")
 
-    # E2B Sandbox configurations
-    e2b_api_key: Optional[str] = None
-    e2b_sandbox_template_id: Optional[str] = None  # Updated manually
+    # Sandbox Configurations
+    e2b_api_key: str | None = Field(default=None, description="API key for using E2B as a tool sandbox")
+    e2b_sandbox_template_id: str | None = Field(default=None, description="Template ID for E2B Sandbox. Updated Manually.")
 
-    # Tavily search
-    tavily_api_key: Optional[str] = None
+    modal_api_key: str | None = Field(default=None, description="API key for using Modal as a tool sandbox")
 
-    # Firecrawl search
-    firecrawl_api_key: Optional[str] = None
+    # Search Providers
+    tavily_api_key: str | None = Field(default=None, description="API key for using Tavily as a search provider.")
+    firecrawl_api_key: str | None = Field(default=None, description="API key for using Firecrawl as a search provider.")
 
     # Local Sandbox configurations
     tool_exec_dir: Optional[str] = None
@@ -36,6 +37,15 @@ class ToolSettings(BaseSettings):
     mcp_read_from_config: bool = False  # if False, will throw if attempting to read/write from file
     mcp_disable_stdio: bool = False
 
+    @property
+    def sandbox_type(self) -> SandboxType:
+        if self.e2b_api_key:
+            return SandboxType.E2B
+        elif self.modal_api_key:
+            return SandboxType.MODAL
+        else:
+            return SandboxType.LOCAL
+
 
 class SummarizerSettings(BaseSettings):
     model_config = SettingsConfigDict(env_prefix="letta_summarizer_", extra="ignore")
diff --git a/letta/utils.py b/letta/utils.py
index 79ba712c..f29ed68b 100644
--- a/letta/utils.py
+++ b/letta/utils.py
@@ -1190,7 +1190,7 @@ async def get_latest_alembic_revision() -> str:
                 return "unknown"
 
     except Exception as e:
-        logger.error(f"Error getting latest alembic revision: {e}")
+        logger.error("Error getting latest alembic revision: %s", e)
         return "unknown"
 
 
diff --git a/poetry.lock b/poetry.lock
index e49be390..44197a05 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -1136,14 +1136,14 @@ files = [
 
 [[package]]
 name = "click"
-version = "8.2.1"
+version = "8.1.8"
 description = "Composable command line interface toolkit"
 optional = false
-python-versions = ">=3.10"
+python-versions = ">=3.7"
 groups = ["main", "dev"]
 files = [
-    {file = "click-8.2.1-py3-none-any.whl", hash = "sha256:61a3265b914e850b85317d0b3109c7f8cd35a670f963866005d6ef1d5175a12b"},
-    {file = "click-8.2.1.tar.gz", hash = "sha256:27c491cc05d968d271d5a1db13e3b5a184636d9d930f148c50b038f0d0646202"},
+    {file = "click-8.1.8-py3-none-any.whl", hash = "sha256:63c132bbbed01578a06712a2d1f497bb62d9c1c0d329b7903a866228027263b2"},
+    {file = "click-8.1.8.tar.gz", hash = "sha256:ed53c9d8990d83c2a27deae68e4ee337473f6330c040a31d4225c9574d16096a"},
 ]
 
 [package.dependencies]
@@ -2808,6 +2808,26 @@ grpcio = ">=1.71.2"
 protobuf = ">=5.26.1,<6.0dev"
 setuptools = "*"
 
+[[package]]
+name = "grpclib"
+version = "0.4.8"
+description = "Pure-Python gRPC implementation for asyncio"
+optional = true
+python-versions = ">=3.8"
+groups = ["main"]
+markers = "extra == \"cloud-tool-sandbox\""
+files = [
+    {file = "grpclib-0.4.8-py3-none-any.whl", hash = "sha256:a5047733a7acc1c1cee6abf3c841c7c6fab67d2844a45a853b113fa2e6cd2654"},
+    {file = "grpclib-0.4.8.tar.gz", hash = "sha256:d8823763780ef94fed8b2c562f7485cf0bbee15fc7d065a640673667f7719c9a"},
+]
+
+[package.dependencies]
+h2 = ">=3.1.0,<5"
+multidict = "*"
+
+[package.extras]
+protobuf = ["protobuf (>=3.20.0)"]
+
 [[package]]
 name = "h11"
 version = "0.16.0"
@@ -2820,6 +2840,36 @@ files = [
     {file = "h11-0.16.0.tar.gz", hash = "sha256:4e35b956cf45792e4caa5885e69fba00bdbc6ffafbfa020300e549b208ee5ff1"},
 ]
 
+[[package]]
+name = "h2"
+version = "4.2.0"
+description = "Pure-Python HTTP/2 protocol implementation"
+optional = true
+python-versions = ">=3.9"
+groups = ["main"]
+markers = "extra == \"cloud-tool-sandbox\""
+files = [
+    {file = "h2-4.2.0-py3-none-any.whl", hash = "sha256:479a53ad425bb29af087f3458a61d30780bc818e4ebcf01f0b536ba916462ed0"},
+    {file = "h2-4.2.0.tar.gz", hash = "sha256:c8a52129695e88b1a0578d8d2cc6842bbd79128ac685463b887ee278126ad01f"},
+]
+
+[package.dependencies]
+hpack = ">=4.1,<5"
+hyperframe = ">=6.1,<7"
+
+[[package]]
+name = "hpack"
+version = "4.1.0"
+description = "Pure-Python HPACK header encoding"
+optional = true
+python-versions = ">=3.9"
+groups = ["main"]
+markers = "extra == \"cloud-tool-sandbox\""
+files = [
+    {file = "hpack-4.1.0-py3-none-any.whl", hash = "sha256:157ac792668d995c657d93111f46b4535ed114f0c9c8d672271bbec7eae1b496"},
+    {file = "hpack-4.1.0.tar.gz", hash = "sha256:ec5eca154f7056aa06f196a557655c5b009b382873ac8d1e66e79e87535f1dca"},
+]
+
 [[package]]
 name = "html2text"
 version = "2020.1.16"
@@ -2922,6 +2972,19 @@ files = [
 [package.dependencies]
 pyreadline3 = {version = "*", markers = "sys_platform == \"win32\" and python_version >= \"3.8\""}
 
+[[package]]
+name = "hyperframe"
+version = "6.1.0"
+description = "Pure-Python HTTP/2 framing"
+optional = true
+python-versions = ">=3.9"
+groups = ["main"]
+markers = "extra == \"cloud-tool-sandbox\""
+files = [
+    {file = "hyperframe-6.1.0-py3-none-any.whl", hash = "sha256:b03380493a519fce58ea5af42e4a42317bf9bd425596f7a0835ffce80f1a42e5"},
+    {file = "hyperframe-6.1.0.tar.gz", hash = "sha256:f630908a00854a7adeabd6382b43923a4c4cd4b821fcb527e6ab9e15382a3b08"},
+]
+
 [[package]]
 name = "identify"
 version = "2.6.12"
@@ -4499,6 +4562,34 @@ typing-inspection = ">=0.4.0"
 agents = ["authlib (>=1.5.2,<2.0)", "griffe (>=1.7.3,<2.0)", "mcp (>=1.0,<2.0) ; python_version >= \"3.10\""]
 gcp = ["google-auth (>=2.27.0)", "requests (>=2.32.3)"]
 
+[[package]]
+name = "modal"
+version = "1.1.0"
+description = "Python client library for Modal"
+optional = true
+python-versions = ">=3.9"
+groups = ["main"]
+markers = "extra == \"cloud-tool-sandbox\""
+files = [
+    {file = "modal-1.1.0-py3-none-any.whl", hash = "sha256:985f47427f214e098768995782fda3915141af5f84007815db0c10c45e4a6a16"},
+    {file = "modal-1.1.0.tar.gz", hash = "sha256:190ea96d45fbdfd6d6cb545a736bf1ef5599511d346ae94cfd773528a33b6097"},
+]
+
+[package.dependencies]
+aiohttp = "*"
+certifi = "*"
+click = ">=8.1.0,<8.2.0"
+grpclib = ">=0.4.7,<0.4.9"
+protobuf = ">=3.19,<4.24.0 || >4.24.0,<7.0"
+rich = ">=12.0.0"
+synchronicity = ">=0.10.1,<0.11.0"
+toml = "*"
+typer = ">=0.9"
+types-certifi = "*"
+types-toml = "*"
+typing_extensions = ">=4.6,<5.0"
+watchfiles = "*"
+
 [[package]]
 name = "mpmath"
 version = "1.3.0"
@@ -7374,6 +7465,26 @@ files = [
     {file = "shellingham-1.5.4.tar.gz", hash = "sha256:8dbca0739d487e5bd35ab3ca4b36e11c4078f3a234bfce294b0a0291363404de"},
 ]
 
+[[package]]
+name = "sigtools"
+version = "4.0.1"
+description = "Utilities for working with inspect.Signature objects."
+optional = true
+python-versions = ">=3.6"
+groups = ["main"]
+markers = "extra == \"cloud-tool-sandbox\""
+files = [
+    {file = "sigtools-4.0.1-py2.py3-none-any.whl", hash = "sha256:d216b4cf920bbab0fce636ddc429ed8463a5b533d9e1492acb45a2a1bc36ac6c"},
+    {file = "sigtools-4.0.1.tar.gz", hash = "sha256:4b8e135a9cd4d2ea00da670c093372d74e672ba3abb87f4c98d8e73dea54445c"},
+]
+
+[package.dependencies]
+attrs = "*"
+
+[package.extras]
+test = ["coverage", "mock", "repeated-test (>=2.2.1)", "sphinx"]
+tests = ["coverage", "mock", "repeated-test (>=2.2.1)", "sphinx"]
+
 [[package]]
 name = "simple-websocket"
 version = "1.1.0"
@@ -7709,6 +7820,23 @@ mpmath = ">=1.1.0,<1.4"
 [package.extras]
 dev = ["hypothesis (>=6.70.0)", "pytest (>=7.1.0)"]
 
+[[package]]
+name = "synchronicity"
+version = "0.10.1"
+description = "Export blocking and async library versions from a single async implementation"
+optional = true
+python-versions = ">=3.8"
+groups = ["main"]
+markers = "extra == \"cloud-tool-sandbox\""
+files = [
+    {file = "synchronicity-0.10.1-py3-none-any.whl", hash = "sha256:af9c077586cf4895aea88fe9104d966f50b8fac730f79117383591acb5489952"},
+    {file = "synchronicity-0.10.1.tar.gz", hash = "sha256:4af861f215a11b885e18cf2985ba8b3a1aa0000d440a9b615402f724a453a8c2"},
+]
+
+[package.dependencies]
+sigtools = ">=4.0.1"
+typing-extensions = ">=4.12.2"
+
 [[package]]
 name = "tavily-python"
 version = "0.7.10"
@@ -7807,10 +7935,10 @@ files = [
 name = "toml"
 version = "0.10.2"
 description = "Python Library for Tom's Obvious, Minimal Language"
-optional = false
+optional = true
 python-versions = ">=2.6, !=3.0.*, !=3.1.*, !=3.2.*"
 groups = ["main"]
-markers = "python_version == \"3.10\""
+markers = "extra == \"cloud-tool-sandbox\" or python_version == \"3.10\""
 files = [
     {file = "toml-0.10.2-py2.py3-none-any.whl", hash = "sha256:806143ae5bfb6a3c6e736a764057db0e6a0e05e338b5630894a5f779cabb4f9b"},
     {file = "toml-0.10.2.tar.gz", hash = "sha256:b3bda1d108d5dd99f4a20d24d9c348e91c4db7ab1b749200bded2f839ccbe68f"},
@@ -7938,6 +8066,32 @@ rich = ">=10.11.0"
 shellingham = ">=1.3.0"
 typing-extensions = ">=3.7.4.3"
 
+[[package]]
+name = "types-certifi"
+version = "2021.10.8.3"
+description = "Typing stubs for certifi"
+optional = true
+python-versions = "*"
+groups = ["main"]
+markers = "extra == \"cloud-tool-sandbox\""
+files = [
+    {file = "types-certifi-2021.10.8.3.tar.gz", hash = "sha256:72cf7798d165bc0b76e1c10dd1ea3097c7063c42c21d664523b928e88b554a4f"},
+    {file = "types_certifi-2021.10.8.3-py3-none-any.whl", hash = "sha256:b2d1e325e69f71f7c78e5943d410e650b4707bb0ef32e4ddf3da37f54176e88a"},
+]
+
+[[package]]
+name = "types-toml"
+version = "0.10.8.20240310"
+description = "Typing stubs for toml"
+optional = true
+python-versions = ">=3.8"
+groups = ["main"]
+markers = "extra == \"cloud-tool-sandbox\""
+files = [
+    {file = "types-toml-0.10.8.20240310.tar.gz", hash = "sha256:3d41501302972436a6b8b239c850b26689657e25281b48ff0ec06345b8830331"},
+    {file = "types_toml-0.10.8.20240310-py3-none-any.whl", hash = "sha256:627b47775d25fa29977d9c70dc0cbab3f314f32c8d8d0c012f2ef5de7aaec05d"},
+]
+
 [[package]]
 name = "typing-extensions"
 version = "4.14.1"
@@ -8145,7 +8299,7 @@ description = "Simple, modern and high performance file watching and code reload
 optional = true
 python-versions = ">=3.9"
 groups = ["main"]
-markers = "extra == \"experimental\" or extra == \"all\""
+markers = "extra == \"experimental\" or extra == \"all\" or extra == \"cloud-tool-sandbox\""
 files = [
     {file = "watchfiles-1.1.0-cp310-cp310-macosx_10_12_x86_64.whl", hash = "sha256:27f30e14aa1c1e91cb653f03a63445739919aef84c8d2517997a83155e7a2fcc"},
     {file = "watchfiles-1.1.0-cp310-cp310-macosx_11_0_arm64.whl", hash = "sha256:3366f56c272232860ab45c77c3ca7b74ee819c8e1f6f35a7125556b198bbc6df"},
@@ -8851,7 +9005,7 @@ cffi = ["cffi (>=1.11)"]
 [extras]
 all = ["autoflake", "black", "docker", "fastapi", "google-cloud-profiler", "granian", "isort", "langchain", "langchain-community", "locust", "pexpect", "pg8000", "pgvector", "pinecone", "pre-commit", "psycopg2", "psycopg2-binary", "pyright", "pytest-asyncio", "pytest-order", "redis", "uvicorn", "uvloop", "wikipedia"]
 bedrock = ["aioboto3", "boto3"]
-cloud-tool-sandbox = ["e2b-code-interpreter"]
+cloud-tool-sandbox = ["e2b-code-interpreter", "modal"]
 desktop = ["docker", "fastapi", "langchain", "langchain-community", "locust", "pyright", "sqlite-vec", "uvicorn", "wikipedia"]
 dev = ["autoflake", "black", "isort", "locust", "pexpect", "pre-commit", "pyright", "pytest-asyncio", "pytest-order"]
 experimental = ["google-cloud-profiler", "granian", "uvloop"]
@@ -8866,4 +9020,4 @@ tests = ["wikipedia"]
 [metadata]
 lock-version = "2.1"
 python-versions = "<3.14,>=3.10"
-content-hash = "6ed92bd1cd08f0365c819c140b131634763d0f35035ad32c536c397cd99f0259"
+content-hash = "6511c865acfab5a77a5c4a3952b48e403cfdc02ddc7210e08349c4bb5d93295f"
diff --git a/pyproject.toml b/pyproject.toml
index 5c770187..68be7f4c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -104,6 +104,7 @@ markitdown = {extras = ["docx", "pdf", "pptx"], version = "^0.1.2"}
 google-cloud-profiler = {version = "^4.1.0", optional = true}
 sqlite-vec = {version = "^0.1.7a2", optional = true}
 orjson = "^3.11.1"
+modal = {version = "^1.1.0", optional = true}
 
 
 [tool.poetry.extras]
@@ -113,7 +114,7 @@ pinecone = ["pinecone"]
 dev = ["pytest", "pytest-asyncio", "pexpect", "black", "pre-commit", "pyright", "pytest-order", "autoflake", "isort", "locust"]
 experimental = ["uvloop", "granian", "google-cloud-profiler"]
 server = ["websockets", "fastapi", "uvicorn"]
-cloud-tool-sandbox = ["e2b-code-interpreter"]
+cloud-tool-sandbox = ["e2b-code-interpreter", "modal"]
 external-tools = ["docker", "langchain", "wikipedia", "langchain-community", "firecrawl-py"]
 tests = ["wikipedia"]
 bedrock = ["boto3", "aioboto3"]
diff --git a/tests/integration_test_async_tool_sandbox.py b/tests/integration_test_async_tool_sandbox.py
index bd01460e..e454aee5 100644
--- a/tests/integration_test_async_tool_sandbox.py
+++ b/tests/integration_test_async_tool_sandbox.py
@@ -526,10 +526,10 @@ async def test_local_sandbox_default(disable_e2b_api_key, add_integers_tool, tes
     args = {"x": 10, "y": 5}
 
     # Mock and assert correct pathway was invoked
-    with patch.object(AsyncToolSandboxLocal, "run_local_dir_sandbox") as mock_run_local_dir_sandbox:
+    with patch.object(AsyncToolSandboxLocal, "run") as mock_run:
         sandbox = AsyncToolSandboxLocal(add_integers_tool.name, args, user=test_user)
         await sandbox.run()
-        mock_run_local_dir_sandbox.assert_called_once()
+        mock_run.assert_called_once()
 
     # Run again to get actual response
     sandbox = AsyncToolSandboxLocal(add_integers_tool.name, args, user=test_user)
@@ -731,10 +731,10 @@ async def test_e2b_sandbox_default(check_e2b_key_is_set, add_integers_tool, test
     args = {"x": 10, "y": 5}
 
     # Mock and assert correct pathway was invoked
-    with patch.object(AsyncToolSandboxE2B, "run_e2b_sandbox") as mock_run_local_dir_sandbox:
+    with patch.object(AsyncToolSandboxE2B, "run") as mock_run:
         sandbox = AsyncToolSandboxE2B(add_integers_tool.name, args, user=test_user)
         await sandbox.run()
-        mock_run_local_dir_sandbox.assert_called_once()
+        mock_run.assert_called_once()
 
     # Run again to get actual response
     sandbox = AsyncToolSandboxE2B(add_integers_tool.name, args, user=test_user)
diff --git a/tests/test_managers.py b/tests/test_managers.py
index 28b5cdcb..9ea3c78b 100644
--- a/tests/test_managers.py
+++ b/tests/test_managers.py
@@ -54,7 +54,7 @@ from letta.schemas.agent import CreateAgent, UpdateAgent
 from letta.schemas.block import Block as PydanticBlock
 from letta.schemas.block import BlockUpdate, CreateBlock
 from letta.schemas.embedding_config import EmbeddingConfig
-from letta.schemas.enums import ActorType, AgentStepStatus, FileProcessingStatus, JobStatus, JobType, MessageRole, ProviderType
+from letta.schemas.enums import ActorType, AgentStepStatus, FileProcessingStatus, JobStatus, JobType, MessageRole, ProviderType, SandboxType
 from letta.schemas.environment_variables import SandboxEnvironmentVariableCreate, SandboxEnvironmentVariableUpdate
 from letta.schemas.file import FileMetadata
 from letta.schemas.file import FileMetadata as PydanticFileMetadata
@@ -76,7 +76,7 @@ from letta.schemas.organization import OrganizationUpdate
 from letta.schemas.passage import Passage as PydanticPassage
 from letta.schemas.pip_requirement import PipRequirement
 from letta.schemas.run import Run as PydanticRun
-from letta.schemas.sandbox_config import E2BSandboxConfig, LocalSandboxConfig, SandboxConfigCreate, SandboxConfigUpdate, SandboxType
+from letta.schemas.sandbox_config import E2BSandboxConfig, LocalSandboxConfig, SandboxConfigCreate, SandboxConfigUpdate
 from letta.schemas.source import Source as PydanticSource
 from letta.schemas.source import SourceUpdate
 from letta.schemas.tool import Tool as PydanticTool
@@ -3560,9 +3560,9 @@ def test_update_tool_by_id(server: SyncServer, print_tool, default_user):
     assert updated_tool.tool_type == ToolType.CUSTOM
 
     # Dangerous: we bypass safety to give it another tool type
-    server.tool_manager.update_tool_by_id(print_tool.id, tool_update, actor=default_user, updated_tool_type=ToolType.EXTERNAL_LANGCHAIN)
+    server.tool_manager.update_tool_by_id(print_tool.id, tool_update, actor=default_user, updated_tool_type=ToolType.EXTERNAL_MCP)
     updated_tool = server.tool_manager.get_tool_by_id(print_tool.id, actor=default_user)
-    assert updated_tool.tool_type == ToolType.EXTERNAL_LANGCHAIN
+    assert updated_tool.tool_type == ToolType.EXTERNAL_MCP
 
 
 def test_update_tool_source_code_refreshes_schema_and_name(server: SyncServer, print_tool, default_user):
diff --git a/tests/test_server.py b/tests/test_server.py
index ec9007cc..dd0727ac 100644
--- a/tests/test_server.py
+++ b/tests/test_server.py
@@ -14,11 +14,10 @@ import letta.utils as utils
 from letta.constants import BASE_MEMORY_TOOLS, BASE_TOOLS, LETTA_DIR, LETTA_TOOL_EXECUTION_DIR
 from letta.orm import Provider, ProviderTrace, Step
 from letta.schemas.block import CreateBlock
-from letta.schemas.enums import MessageRole, ProviderCategory, ProviderType
+from letta.schemas.enums import MessageRole, ProviderCategory, ProviderType, SandboxType
 from letta.schemas.letta_message import LettaMessage, ReasoningMessage, SystemMessage, ToolCallMessage, ToolReturnMessage, UserMessage
 from letta.schemas.llm_config import LLMConfig
 from letta.schemas.providers import ProviderCreate
-from letta.schemas.sandbox_config import SandboxType
 from letta.schemas.user import User
 from letta.server.db import db_registry