langchain-ai/deepagents · error · ValueError

Store item does not contain valid content field. Got: {store

Error message

Store item does not contain valid content field. Got: {store_item.value.keys()}

What it means

When converting a persisted BaseStore item into `FileData`, `_convert_store_item_to_file_data` expects a `content` key in the item's value. If `value.get('content')` is None (missing or explicitly None), the item is considered corrupt/incompatible and a ValueError is raised listing the keys that were actually present.

Source

Thrown at libs/deepagents/deepagents/backends/store.py:188

    def _convert_store_item_to_file_data(self, store_item: Item) -> FileData:
        """Convert current and legacy persisted store content to `FileData`.

        Args:
            store_item: The store `Item` containing file data.

        Returns:
            `FileData` with string content and encoding. Legacy `list[str]`
                content is joined without modifying the persisted item. Includes
                `created_at` and `modified_at` when present.

        Raises:
            ValueError: If the store item has no content.
            TypeError: If content is neither a string nor a legacy list of strings.
        """
        raw_content = store_item.value.get("content")
        if raw_content is None:
            msg = f"Store item does not contain valid content field. Got: {store_item.value.keys()}"
            raise ValueError(msg)

        if isinstance(raw_content, list) and all(isinstance(line, str) for line in raw_content):
            content = "\n".join(raw_content)
        elif isinstance(raw_content, str):
            content = raw_content
        else:
            msg = f"Store item `content` must be a `str` or legacy `list[str]`, got {type(raw_content).__name__}."
            raise TypeError(msg)

        result = FileData(
            content=content,
            encoding=store_item.value.get("encoding", "utf-8"),
        )
        if "created_at" in store_item.value and isinstance(store_item.value["created_at"], str):
            result["created_at"] = store_item.value["created_at"]
        if "modified_at" in store_item.value and isinstance(store_item.value["modified_at"], str):
            result["modified_at"] = store_item.value["modified_at"]
        return result

View on GitHub (pinned to a1af029e6e)

Solutions

1. Ensure every store item written includes a `content` key (str or list[str]) under `value`
2. Migrate or delete legacy store entries that lack `content` before reading them through StoreBackend
3. Filter store search results to items your app wrote (e.g. include a `kind` marker in value and skip others)
4. Inspect the reported keys in the message to find which schema the item actually uses

Example fix

// before
store.put(('filesystem',), '/a.txt', {'text': 'hello'})
// after
store.put(('filesystem',), '/a.txt', {'content': 'hello'})

def writable_value(content, encoding='utf-8'):
    if content is None:
        raise ValueError('content is required')
    if isinstance(content, str) or (isinstance(content, list) and all(isinstance(l, str) for l in content)):
        return {'content': content, 'encoding': encoding}
    raise TypeError(f'unsupported content: {type(content).__name__}')
store.put(('filesystem',), '/a.txt', writable_value('hello'))

def has_content(value: dict) -> bool:
    c = value.get('content')
    return c is not None and (
        isinstance(c, str)
        or (isinstance(c, list) and all(isinstance(l, str) for l in c))
    )

try:
    data = backend.read('/a.txt')
except ValueError as exc:
    if 'does not contain valid content field' in str(exc):
        data = None  # skip/migrate the corrupt store item
    else:
        raise

When it happens

Trigger: Reading store items written by other code that used a different value schema (no `content` key); store entries manually deleted/partially written; deserializing items from a different backend or an older/custom writer that stored content under a different key.

Common situations: Upgrading from a custom store writer to StoreBackend; sharing one BaseStore between multiple apps with conflicting schemas; hand-seeding an InMemoryStore in tests with items lacking `content`.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

• Store item `content` must be a `str` or legacy `list[str]`,
• Could not parse embedded resource block. Block expected eith
• {question_type} question {question_text!r} must not define '
• Offload server returned a non-object response.
• Offload server returned an invalid operation response.

AI-assisted analysis of langchain-ai/deepagents@a1af029e6e (2026-08-29). Data as JSON: /api/errors/5a4ce4844407ef29. Report an issue: GitHub.