stateful proxy

src/wf_mcp/broker/config.py

@@ -7,6 +7,7 @@ from wf_artifacts import FileDraftWorkspaceStore, FileWorkflowArtifactStore
 
 from ..control import BrokerConfigFile
 from ..models import BrokerConfig
+from ..runtime import McpRuntimePool, PersistentSessionFactory
 from ..sdk import McpSdkAdapter
 from ..storage import FileStore
 from .service import WfMcpService
@@ -21,10 +22,15 @@ def load_broker_config(path: str | Path) -> BrokerConfig:
 
 def build_service_from_config(config: BrokerConfig) -> WfMcpService:
     """Create a broker service with SDK adapters for configured connections."""
+    runtime_factory = PersistentSessionFactory()
     service = WfMcpService(
         store=FileStore(config.store_root),
         artifact_store=FileWorkflowArtifactStore(config.store_root),
         draft_workspace_store=FileDraftWorkspaceStore(config.store_root),
+        # Discovery can use short-lived SDK sessions. Workflow execution needs
+        # a persistent runtime so stateful MCP servers keep session/page state
+        # across sequential workflow nodes.
+        tool_executor=McpRuntimePool(runtime_factory.create),
     )
     for connection in config.connections:
         service.register_connection(connection)

src/wf_mcp/broker/service/core.py

@@ -41,6 +41,7 @@ from ...models import (
     ConnectionConfig,
     RawWorkflowPlan,
 )
+from ...runtime import ToolExecutor
 from ...sdk import BackendAdapter
 from ...shared.errors import error_payload
 from ...shared.names import RESERVED_CONNECTION_IDS
@@ -72,6 +73,7 @@ class WfMcpService:
     include_builtin_specs: bool = True
     artifact_store: WorkflowArtifactStore | None = None
     draft_workspace_store: DraftWorkspaceStore | None = None
+    tool_executor: ToolExecutor | None = None
 
     def __post_init__(self) -> None:
         """Install broker-local system specs when enabled."""
@@ -130,6 +132,17 @@ class WfMcpService:
     def register_adapter(self, server: str, adapter: BackendAdapter) -> None:
         self.adapters[server] = adapter
 
+    def _tool_executor_for(self, connection: ConnectionConfig) -> ToolExecutor:
+        """Return the executor used by generated workflow NodeSpecs.
+
+        Discovery still uses the short-lived adapter path. Generated workflow
+        nodes use this executor hook so config-built services can swap in a
+        persistent runtime pool for stateful MCP servers.
+        """
+        if self.tool_executor is not None:
+            return self.tool_executor
+        return require_adapter(connection, self.adapters)
+
     def save_auth(self, record: AuthRecord) -> None:
         self.store.save_auth(record)
         self._record_event(
@@ -606,7 +619,7 @@ class WfMcpService:
             specs = specs_from_discovered_tools(
                 connection=connection,
                 auth=auth,
-                executor=adapter,
+                executor=self._tool_executor_for(connection),
                 tools=capabilities.tools,
                 emit_event=self._record_event,
             )