redis/redis-py · error · DataError

No key specified

Error message

No key specified

What it means

Raised by JSON.debug() when subcommand is 'MEMORY' but no key argument was supplied. The MEMORY subcommand reports bytes used by a value at a specific key, so the key is mandatory; HELP is the only subcommand that works without one.

Source

Thrown at redis/commands/json/commands.py:830

    def debug(
        self,
        subcommand: str,
        key: str | None = None,
        path: str | None = Path.root_path(),
    ) -> (int | list[str]) | Awaitable[int | list[str]]:
        """Return the memory usage in bytes of a value under ``path`` from
        key ``name``.

        For more information see `JSON.DEBUG <https://redis.io/commands/json.debug>`_.
        """  # noqa
        valid_subcommands = ["MEMORY", "HELP"]
        if subcommand not in valid_subcommands:
            raise DataError("The only valid subcommands are ", str(valid_subcommands))
        pieces = [subcommand]
        if subcommand == "MEMORY":
            if key is None:
                raise DataError("No key specified")
            pieces.append(key)
            pieces.append(str(path))
        return self.execute_command("JSON.DEBUG", *pieces)

    @overload
    def jsonget(self: SyncClientProtocol, *args, **kwargs) -> JsonType | None: ...

    @overload
    def jsonget(
        self: AsyncClientProtocol, *args, **kwargs
    ) -> Awaitable[JsonType | None]: ...

    @deprecated_function(
        version="4.0.0", reason="redisjson-py supported this, call get directly."
    )
    def jsonget(self, *args, **kwargs) -> (JsonType | None) | Awaitable[
        JsonType | None
    ]:

View on GitHub (pinned to da03cdc7e8)

Solutions

1. Always pass a key with the MEMORY subcommand: debug('MEMORY', 'mykey').
2. Guard before calling: if key is None: skip or raise your own error.
3. Use debug('HELP') if you only want usage text.

Example fix

// before
client.json().debug('MEMORY')
// after
client.json().debug('MEMORY', 'mykey')

def json_debug_memory(client, key, path="$"):
    if key is None:
        raise ValueError("MEMORY subcommand requires a key")
    return client.json().debug("MEMORY", key, path)

def has_key(v) -> bool:
    return v is not None and (not isinstance(v, str) or v != "")

from redis.exceptions import DataError
try:
    client.json().debug("MEMORY", key)
except DataError as e:
    if "No key specified" in str(e):
        raise ValueError("caller must supply a non-None key") from e
    raise

When it happens

Trigger: Call client.json().debug('MEMORY') with key left as the default None, or client.json().debug('MEMORY', None).

Common situations: Forgetting the positional key; passing key from a variable that is None on missing input; refactoring that drops the key argument.

Related errors

• The only valid subcommands are
• Invalid FPHA type: {value}. Must be one of {', '.join(t.valu
• CLIENT KILL type must be one of {client_types!r}
• CLIENT KILL skipme must be a bool
• CLIENT KILL <filter> <value> ... ... <filter> <value> must s

AI-assisted analysis of redis/redis-py@da03cdc7e8 (2026-08-04). Data as JSON: /data/errors/16e1800381cebfe2.json. Report an issue: GitHub.