{
    "XNACK": {
        "summary": "Releases claimed messages back to the group's PEL without acknowledging them, making them available for re-delivery.",
        "complexity": "O(1) for each message ID processed.",
        "group": "stream",
        "since": "8.8.0",
        "arity": -7,
        "function": "xnackCommand",
        "command_flags": [
            "WRITE",
            "FAST"
        ],
        "acl_categories": [
            "STREAM"
        ],
        "key_specs": [
            {
                "flags": [
                    "RW",
                    "UPDATE"
                ],
                "begin_search": {
                    "index": {
                        "pos": 1
                    }
                },
                "find_keys": {
                    "range": {
                        "lastkey": 0,
                        "step": 1,
                        "limit": 0
                    }
                }
            }
        ],
        "arguments": [
            {
                "name": "key",
                "type": "key",
                "key_spec_index": 0
            },
            {
                "name": "group",
                "type": "string"
            },
            {
                "name": "mode",
                "type": "oneof",
                "arguments": [
                    {
                        "name": "silent",
                        "type": "pure-token",
                        "token": "SILENT"
                    },
                    {
                        "name": "fail",
                        "type": "pure-token",
                        "token": "FAIL"
                    },
                    {
                        "name": "fatal",
                        "type": "pure-token",
                        "token": "FATAL"
                    }
                ]
            },
            {
                "name": "ids",
                "token": "IDS",
                "type": "block",
                "arguments": [
                    {
                        "name": "numids",
                        "type": "integer"
                    },
                    {
                        "name": "id",
                        "type": "string",
                        "multiple": true
                    }
                ]
            },
            {
                "token": "RETRYCOUNT",
                "name": "count",
                "type": "integer",
                "optional": true
            },
            {
                "name": "force",
                "token": "FORCE",
                "type": "pure-token",
                "optional": true
            }
        ],
        "reply_schema": {
            "description": "The number of messages successfully NACKed (released back to the group PEL).",
            "type": "integer",
            "minimum": 0
        }
    }
}
