As part of SPM-4048, a new field called versionContext has been added to the output of the $currentOp command. This field describes the versioning used by the running operation, which determines which features are available.

The format of this field should be considered internal to the server and external tools must not rely on it having any particular value. Rather, the indented use is for aiding in troubleshooting problems during upgrade/downgrade ((setFeatureCompatibilityVersion).

In its present state, this field is planned to be released in MongoDB 8.2+. Currently, this field is optional and is only present for DDL operations, however its usage may be extended in the future.

Example $currentOp output containing the versionContext field:

[
	{
		"shard" : "shard-rs1",
		"type" : "op",
		"host" : "ip-10-0-67-40:20002",
		"desc" : "ShardingDDLCoordinator-2",
		"active" : true,
		"currentOpTime" : "2025-03-18T16:28:55.236+00:00",
		"effectiveUsers" : [
			{
				"user" : "__system",
				"db" : "local"
			}
		],
		"isFromUserConnection" : false,
		"opid" : "shard-rs1:102415",
		"versionContext" : {
			"OFCV" : "8.2"
		},
		"op" : "none",
		"ns" : "",
		[...]
	}
]

Description of Linked Ticket

Include operation FCV in $currentOp aggregation stage results, in order to improve observability and help diagnose issues that happen during upgrade/downgrade.