{"record":{"id":"7d254958c485e842","repo":"langchain-ai/langgraph","slug":"managed-value-key-already-exists-with-a-differ","errorCode":null,"errorMessage":"Managed value '{key}' already exists with a different type","messagePattern":"Managed value '(.+?)' already exists with a different type","errorType":"validation","errorClass":"ValueError","httpStatus":null,"severity":"error","filePath":"libs/langgraph/langgraph/graph/state.py","lineNumber":369,"sourceCode":"                    f\"Invalid managed channels detected in {schema_name}: {names}.\"\n                    \" Managed channels are not permitted in Input/Output schema.\"\n                )\n            self.schemas[schema] = {**channels, **managed}\n            for key, channel in channels.items():\n                if key in self.channels:\n                    if self.channels[key] != channel:\n                        if isinstance(channel, LastValue):\n                            pass\n                        else:\n                            raise ValueError(\n                                f\"Channel '{key}' already exists with a different type\"\n                            )\n                else:\n                    self.channels[key] = channel\n            for key, managed in managed.items():\n                if key in self.managed:\n                    if self.managed[key] != managed:\n                        raise ValueError(\n                            f\"Managed value '{key}' already exists with a different type\"\n                        )\n                else:\n                    self.managed[key] = managed\n\n    @overload\n    def add_node(\n        self,\n        node: StateNode[NodeInputT, ContextT],\n        *,\n        defer: bool = False,\n        metadata: dict[str, Any] | None = None,\n        input_schema: None = None,\n        retry_policy: RetryPolicy | Sequence[RetryPolicy] | None = None,\n        cache_policy: CachePolicy | None = None,\n        error_handler: StateNode[Any, ContextT] | None = None,\n        destinations: dict[str, str] | tuple[str, ...] | None = None,\n        timeout: float | timedelta | TimeoutPolicy | None = None,","sourceCodeStart":351,"sourceCodeEnd":387,"githubUrl":"https://github.com/langchain-ai/langgraph/blob/38031739e551638e373fb553453256c23feeb41f/libs/langgraph/langgraph/graph/state.py#L351-L387","documentation":"Error \"Managed value '{key}' already exists with a different type\" thrown in langchain-ai/langgraph.","triggerScenarios":"Thrown at libs/langgraph/langgraph/graph/state.py:369 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"38031739e551638e373fb553453256c23feeb41f","analyzedAt":"2026-08-26T18:02:49.312Z","schemaVersion":2},"datasetVersion":"2026-08-26T21:11:00.512Z"}