{"record":{"id":"4bd9a666e68c5227","repo":"langchain-ai/langgraph","slug":"invalid-write-entry-w","errorCode":null,"errorMessage":"Invalid write entry: {w}","messagePattern":"Invalid write entry: (.+?)","errorType":"exception","errorClass":"ValueError","httpStatus":null,"severity":"error","filePath":"libs/langgraph/langgraph/pregel/_write.py","lineNumber":191,"sourceCode":"    writes: Sequence[ChannelWriteEntry | ChannelWriteTupleEntry | Send],\n) -> list[tuple[str, Any]]:\n    \"\"\"Assembles the writes into a list of tuples.\"\"\"\n    tuples: list[tuple[str, Any]] = []\n    for w in writes:\n        if isinstance(w, Send):\n            tuples.append((TASKS, w))\n        elif isinstance(w, ChannelWriteTupleEntry):\n            if ww := w.mapper(w.value):\n                tuples.extend(ww)\n        elif isinstance(w, ChannelWriteEntry):\n            value = w.mapper(w.value) if w.mapper is not None else w.value\n            if value is SKIP_WRITE:\n                continue\n            if w.skip_none and value is None:\n                continue\n            tuples.append((w.channel, value))\n        else:\n            raise ValueError(f\"Invalid write entry: {w}\")\n    return tuples\n","sourceCodeStart":173,"sourceCodeEnd":193,"githubUrl":"https://github.com/langchain-ai/langgraph/blob/38031739e551638e373fb553453256c23feeb41f/libs/langgraph/langgraph/pregel/_write.py#L173-L193","documentation":"Error \"Invalid write entry: {w}\" thrown in langchain-ai/langgraph.","triggerScenarios":"Thrown at libs/langgraph/langgraph/pregel/_write.py:191 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"}