{
    "HLEN": {
        "summary": "Returns the number of fields in a hash.",
        "complexity": "O(1)",
        "group": "hash",
        "since": "2.0.0",
        "arity": 2,
        "function": "hlenCommand",
        "command_flags": [
            "READONLY",
            "FAST"
        ],
        "acl_categories": [
            "HASH"
        ],
        "key_specs": [
            {
                "flags": [
                    "RO"
                ],
                "begin_search": {
                    "index": {
                        "pos": 1
                    }
                },
                "find_keys": {
                    "range": {
                        "lastkey": 0,
                        "step": 1,
                        "limit": 0
                    }
                }
            }
        ],
        "reply_schema": {
            "type": "integer",
            "description": "Number of the fields in the hash, or 0 when the key does not exist."
        },
        "arguments": [
            {
                "name": "key",
                "type": "key",
                "key_spec_index": 0
            }
        ]
    }
}
