{"record":{"id":"01f15189d965ee84","repo":"langchain-ai/langgraph","slug":"emptychannelerror-01f151","errorCode":null,"errorMessage":"EmptyChannelError","messagePattern":"EmptyChannelError","errorType":"exception","errorClass":"EmptyChannelError","httpStatus":null,"severity":"error","filePath":"libs/langgraph/langgraph/channels/delta.py","lineNumber":187,"sourceCode":"                        error_code=ErrorCode.INVALID_CONCURRENT_GRAPH_UPDATE,\n                    )\n                    raise InvalidUpdateError(msg)\n                overwrite_idx = i\n        if overwrite_idx is not None:\n            _, overwrite_value = _get_overwrite(values[overwrite_idx])\n            self.value = (\n                _copy.copy(overwrite_value)\n                if overwrite_value is not None\n                else self.typ()\n            )\n            return True\n        base = self.typ() if self.value is MISSING else self.value\n        self.value = self.reducer(base, list(values))\n        return True\n\n    def get(self) -> Any:\n        if self.value is MISSING:\n            raise EmptyChannelError()\n        return self.value\n\n    def is_available(self) -> bool:\n        return self.value is not MISSING\n\n    def checkpoint(self) -> Any:\n        \"\"\"Return stored representation: always `MISSING`.\n\n        Snapshot decisions live in `create_checkpoint` (which has the channel\n        version) and write `_DeltaSnapshot(ch.get())` directly into\n        `channel_values`. For non-snapshot steps the channel does not appear\n        in `channel_values`; reconstruction walks ancestor writes via the\n        saver's `get_delta_channel_history`.\n        \"\"\"\n        return MISSING\n","sourceCodeStart":169,"sourceCodeEnd":203,"githubUrl":"https://github.com/langchain-ai/langgraph/blob/38031739e551638e373fb553453256c23feeb41f/libs/langgraph/langgraph/channels/delta.py#L169-L203","documentation":"Error \"EmptyChannelError\" thrown in langchain-ai/langgraph.","triggerScenarios":"Thrown at libs/langgraph/langgraph/channels/delta.py:187 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"}