Cannot Create GSI Vector Index on Capella Free Tier (7.6.x) - "Invalid parameters in with-clause: 'index_type'"

Couchbase Capella
1

Hi everyone,

I’m working through the “Semantic Cache with LangChain” technical challenge on the Capella Free Tier. My cluster is confirmed to be running Couchbase Server 7.6.x .

I have successfully used a Python script to add vector embeddings (384-dim) to the hotel documents in the travel-sample bucket.

My goal is to create a vector index to use the VECTOR_SEARCH() function in a SQL++ query. However, when I try to create the index using the documented syntax, it fails.

DDL Command:

CREATE INDEX ix_hotel_embedding_vector
ON `travel-sample`.inventory.hotel(description_embedding)
WITH {"index_type": "vector", "dimensions": 384, "similarity": "cosine"};

The Error: Whether I run this command in the Capella Query Editor, or send it directly to the Query Service API (port 18093) using curl or Postman, I consistently receive the same error:

{
  "code": 5000,
  "msg": "GSI CreateIndex() - cause: Invalid parameters in with-clause: 'index_type'. Valid parameters are 'nodes', 'defer_build', ...",
  "status": "fatal"
}

This error suggests that the Query Service on this build does not recognize the index_type parameter, which is required for creating a GSI vector index.

Additional Context: My initial approach was to use the Search Service (FTS). However, I was blocked because the Capella Free Tier UI does not provide the necessary fts_searcher or Bucket Admin roles required for my application user to query the Search index.

My Question: Given that the server version is 7.6.x, is the creation of GSI vector indexes disabled or restricted on the Capella Free Tier? Or is there an alternative

2

@timothytadeo We currently do not support creating Vector Indices on the GSI service.
For Vector Search, you need to use the FTS service, which is available on the Free Tier.

You should be able to create indexes on the FTS service via the UI. We do that regularly for our tutorials. What is the error that you are facing?

3

Hi Couchbase ! Thank you for your timely reply.

Between my original post and my iteration through the problem I have it fixed.

Will edit my post later today to document fix…