I had to make 2 changes to make it work.
searchScore => vectorSearchScore
gte => $gte
{
"$vectorSearch": {
"index": "vector_index",
"path": "vector",
"queryVector": [0.456, 0.311, ...],
"numCandidates": 100,
"limit": 10
}
},
{
"$addFields": {"score": {"$meta": "vectorSearchScore"}}
},
{
"$match": {"score": {"$gte": 0.7}}
},
{
"$project": {"vector": 0}
},