Hello all, apologies for the error and for the delayed response. To clarify, the error that you’re seeing here “$vectorSearch is not allowed or the syntax is incorrect, see the Atlas documentation for more information” is due to an issue in M0-M5 Clusters which will be resolved after our deployment tomorrow, it is not related to LangChain.
The origin of this error stems from a slight difference in how our shared tier clusters work when compared to dedicated tier, hence clusters M10 and above are not affected.
To provide a bit more context, $vectorSearch is our target interface for Vector Search in the long term, and as such we’ve updated LangChain to utilize this new syntax. That said, we do not currently have plans to remove support in Atlas for knnBeta, and will not do so until every Cluster in Atlas is running a version that supports $vectorSearch. We will provide additional guidance ahead of any changes to support for knnBeta.
And one last clarification, the entire Vector Search service is in Preview, whether it be through $vectorSearch or knnBeta.
Finally, for anyone who would like to chat in more depth please feel free to follow up here or reach out to me directly at Benjamin.flast@mongodb.com.