{"record":{"id":"3d42cdda6f6a3c3e","repo":"langchain-ai/langgraph","slug":"input-channel-chan-not-in-repr-sorted-channe","errorCode":null,"errorMessage":"Input channel '{chan}' not in '{repr(sorted(channels))[:100]}'","messagePattern":"Input channel '(.+?)' not in '(.+?)'","errorType":"exception","errorClass":"ValueError","httpStatus":null,"severity":"error","filePath":"libs/langgraph/langgraph/pregel/_validate.py","lineNumber":78,"sourceCode":"\n    if isinstance(input_channels, str):\n        if input_channels not in channels:\n            raise ValueError(\n                f\"Input channel '{input_channels}' not \"\n                f\"in known channels: '{repr(sorted(channels))[:100]}'\"\n            )\n        if input_channels not in subscribed_channels:\n            raise ValueError(\n                f\"Input channel {input_channels} is not subscribed to by any node\"\n            )\n    else:\n        for chan in input_channels:\n            if chan not in channels:\n                raise ValueError(\n                    f\"Input channel '{chan}' not in '{repr(sorted(channels))[:100]}'\"\n                )\n        if all(chan not in subscribed_channels for chan in input_channels):\n            raise ValueError(\n                f\"None of the input channels {input_channels} \"\n                f\"are subscribed to by any node\"\n            )\n\n    all_output_channels = set[str]()\n    if isinstance(output_channels, str):\n        all_output_channels.add(output_channels)\n    else:\n        all_output_channels.update(output_channels)\n    if isinstance(stream_channels, str):\n        all_output_channels.add(stream_channels)\n    elif stream_channels is not None:\n        all_output_channels.update(stream_channels)\n\n    for chan in all_output_channels:\n        if chan not in channels:\n            raise ValueError(\n                f\"Output channel '{chan}' not \"","sourceCodeStart":60,"sourceCodeEnd":96,"githubUrl":"https://github.com/langchain-ai/langgraph/blob/38031739e551638e373fb553453256c23feeb41f/libs/langgraph/langgraph/pregel/_validate.py#L60-L96","documentation":"Error \"Input channel '{chan}' not in '{repr(sorted(channels))[:100]}'\" thrown in langchain-ai/langgraph.","triggerScenarios":"Thrown at libs/langgraph/langgraph/pregel/_validate.py:78 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"}