Don't require mcp or logfire to use Temporal or DBOS (#2908)

Author: DouweM

pydantic_ai_slim/pydantic_ai/durable_exec/dbos/_agent.py

@@ -15,7 +15,6 @@
 )
 from pydantic_ai.agent import AbstractAgent, AgentRun, AgentRunResult, EventStreamHandler, RunOutputDataT, WrapperAgent
 from pydantic_ai.exceptions import UserError
-from pydantic_ai.mcp import MCPServer
 from pydantic_ai.models import Model
 from pydantic_ai.output import OutputDataT, OutputSpec
 from pydantic_ai.result import StreamedRunResult
@@ -29,7 +28,6 @@
 )
 from pydantic_ai.toolsets import AbstractToolset
 
-from ._mcp_server import DBOSMCPServer
 from ._model import DBOSModel
 from ._utils import StepConfig
 
@@ -86,14 +84,21 @@ def __init__(
 
         def dbosify_toolset(toolset: AbstractToolset[AgentDepsT]) -> AbstractToolset[AgentDepsT]:
             # Replace MCPServer with DBOSMCPServer
-            if isinstance(toolset, MCPServer):
-                return DBOSMCPServer(
-                    wrapped=toolset,
-                    step_name_prefix=dbosagent_name,
-                    step_config=self._mcp_step_config,
-                )
+            try:
+                from pydantic_ai.mcp import MCPServer
+
+                from ._mcp_server import DBOSMCPServer
+            except ImportError:
+                pass
             else:
-                return toolset
+                if isinstance(toolset, MCPServer):
+                    return DBOSMCPServer(
+                        wrapped=toolset,
+                        step_name_prefix=dbosagent_name,
+                        step_config=self._mcp_step_config,
+                    )
+
+            return toolset
 
         dbos_toolsets = [toolset.visit_and_replace(dbosify_toolset) for toolset in wrapped.toolsets]
         self._toolsets = dbos_toolsets

pydantic_ai_slim/pydantic_ai/durable_exec/dbos/_mcp_server.py

@@ -2,18 +2,20 @@
 
 from abc import ABC
 from collections.abc import Callable
-from typing import Any
+from typing import TYPE_CHECKING, Any
 
 from dbos import DBOS
 from typing_extensions import Self
 
-from pydantic_ai.mcp import MCPServer, ToolResult
 from pydantic_ai.tools import AgentDepsT, RunContext
 from pydantic_ai.toolsets.abstract import AbstractToolset, ToolsetTool
 from pydantic_ai.toolsets.wrapper import WrapperToolset
 
 from ._utils import StepConfig
 
+if TYPE_CHECKING:
+    from pydantic_ai.mcp import MCPServer, ToolResult
+
 
 class DBOSMCPServer(WrapperToolset[AgentDepsT], ABC):
     """A wrapper for MCPServer that integrates with DBOS, turning call_tool and get_tools to DBOS steps."""

pydantic_ai_slim/pydantic_ai/durable_exec/temporal/_logfire.py

@@ -1,14 +1,15 @@
 from __future__ import annotations
 
 from collections.abc import Callable
+from typing import TYPE_CHECKING
 
-from logfire import Logfire
-from opentelemetry.trace import get_tracer
 from temporalio.client import ClientConfig, Plugin as ClientPlugin
-from temporalio.contrib.opentelemetry import TracingInterceptor
 from temporalio.runtime import OpenTelemetryConfig, Runtime, TelemetryConfig
 from temporalio.service import ConnectConfig, ServiceClient
 
+if TYPE_CHECKING:
+    from logfire import Logfire
+
 
 def _default_setup_logfire() -> Logfire:
     import logfire
@@ -22,13 +23,24 @@ class LogfirePlugin(ClientPlugin):
     """Temporal client plugin for Logfire."""
 
     def __init__(self, setup_logfire: Callable[[], Logfire] = _default_setup_logfire, *, metrics: bool = True):
+        try:
+            import logfire  # noqa: F401 # pyright: ignore[reportUnusedImport]
+        except ImportError as _import_error:
+            raise ImportError(
+                'Please install the `logfire` package to use the Logfire plugin, '
+                'you can use the `logfire` optional group — `pip install "pydantic-ai-slim[logfire]"`'
+            ) from _import_error
+
         self.setup_logfire = setup_logfire
         self.metrics = metrics
 
     def init_client_plugin(self, next: ClientPlugin) -> None:
         self.next_client_plugin = next
 
     def configure_client(self, config: ClientConfig) -> ClientConfig:
+        from opentelemetry.trace import get_tracer
+        from temporalio.contrib.opentelemetry import TracingInterceptor
+
         interceptors = config.get('interceptors', [])
         config['interceptors'] = [*interceptors, TracingInterceptor(get_tracer('temporalio'))]
         return self.next_client_plugin.configure_client(config)

pydantic_ai_slim/pydantic_ai/durable_exec/temporal/_toolset.py

@@ -6,7 +6,6 @@
 
 from temporalio.workflow import ActivityConfig
 
-from pydantic_ai.mcp import MCPServer
 from pydantic_ai.tools import AgentDepsT
 from pydantic_ai.toolsets.abstract import AbstractToolset
 from pydantic_ai.toolsets.function import FunctionToolset
@@ -63,16 +62,22 @@ def temporalize_toolset(
             deps_type=deps_type,
             run_context_type=run_context_type,
         )
-    elif isinstance(toolset, MCPServer):
-        from ._mcp_server import TemporalMCPServer
 
-        return TemporalMCPServer(
-            toolset,
-            activity_name_prefix=activity_name_prefix,
-            activity_config=activity_config,
-            tool_activity_config=tool_activity_config,
-            deps_type=deps_type,
-            run_context_type=run_context_type,
-        )
+    try:
+        from pydantic_ai.mcp import MCPServer
+
+        from ._mcp_server import TemporalMCPServer
+    except ImportError:
+        pass
     else:
-        return toolset
+        if isinstance(toolset, MCPServer):
+            return TemporalMCPServer(
+                toolset,
+                activity_name_prefix=activity_name_prefix,
+                activity_config=activity_config,
+                tool_activity_config=tool_activity_config,
+                deps_type=deps_type,
+                run_context_type=run_context_type,
+            )
+
+    return toolset