go-redis/redis · error

FT.CREATE: Type, Dim and DistanceMetric are required for VEC

Error message

FT.CREATE: Type, Dim and DistanceMetric are required for VECTOR FLAT

What it means

Returned by FTCreate when FlatOptions is selected but Type, Dim, or DistanceMetric is unset (Type=="", Dim==0, or DistanceMetric==""). These are the mandatory parameters for a VECTOR FLAT index. The guard is at search_commands.go:1487.

Source

Thrown at search_commands.go:1489

			if schema.VectorArgs.FlatOptions != nil {
				optionCount++
			}
			if schema.VectorArgs.HNSWOptions != nil {
				optionCount++
			}
			if schema.VectorArgs.VamanaOptions != nil {
				optionCount++
			}
			if optionCount != 1 {
				cmd := NewStatusCmd(ctx, args...)
				cmd.SetErr(fmt.Errorf("FT.CREATE: SCHEMA VectorArgs must have exactly one of FlatOptions, HNSWOptions, or VamanaOptions"))
				return cmd
			}
			if schema.VectorArgs.FlatOptions != nil {
				args = append(args, "FLAT")
				if schema.VectorArgs.FlatOptions.Type == "" || schema.VectorArgs.FlatOptions.Dim == 0 || schema.VectorArgs.FlatOptions.DistanceMetric == "" {
					cmd := NewStatusCmd(ctx, args...)
					cmd.SetErr(fmt.Errorf("FT.CREATE: Type, Dim and DistanceMetric are required for VECTOR FLAT"))
					return cmd
				}
				flatArgs := []interface{}{
					"TYPE", schema.VectorArgs.FlatOptions.Type,
					"DIM", schema.VectorArgs.FlatOptions.Dim,
					"DISTANCE_METRIC", schema.VectorArgs.FlatOptions.DistanceMetric,
				}
				if schema.VectorArgs.FlatOptions.InitialCapacity > 0 {
					flatArgs = append(flatArgs, "INITIAL_CAP", schema.VectorArgs.FlatOptions.InitialCapacity)
				}
				if schema.VectorArgs.FlatOptions.BlockSize > 0 {
					flatArgs = append(flatArgs, "BLOCK_SIZE", schema.VectorArgs.FlatOptions.BlockSize)
				}
				args = append(args, len(flatArgs))
				args = append(args, flatArgs...)
			}
			if schema.VectorArgs.HNSWOptions != nil {
				args = append(args, "HNSW")

View on GitHub (pinned to 36d97525cd)

Solutions

1. Set FlatOptions.Type ("FLOAT32"/"FLOAT16"/"BFLOAT16"), FlatOptions.Dim (>0, matches embedding size), and FlatOptions.DistanceMetric ("COSINE"/"L2"/"IP").
2. Load Dim from the embedding model config and assert it is non-zero before index creation.
3. Validate the triplet in a helper before calling FTCreate.

Example fix

// before
&redis.FTFlatOptions{Type: "FLOAT32", Dim: 0}

// after
&redis.FTFlatOptions{Type: "FLOAT32", Dim: 768, DistanceMetric: "COSINE"}

o := f.VectorArgs.FlatOptions
if o.Type == "" || o.Dim == 0 || o.DistanceMetric == "" {
    return fmt.Errorf("FLAT vector field %q needs Type, Dim>0, DistanceMetric", f.FieldName)
}

When it happens

Trigger: Constructing &redis.FTFlatOptions{} without setting Type (e.g. "FLOAT32"), Dim (vector dimensionality > 0), or DistanceMetric (e.g. "COSINE", "L2", "IP").

Common situations: Reading Dim from a config/env that defaults to 0, forgetting the distance metric string, or using an unsupported Type token. Note zero Dim is indistinguishable from unset because Dim is an int.

Related errors

• FT.CREATE: SCHEMA FieldType VECTOR is required for VectorArg
• FT.CREATE: SCHEMA VectorArgs must have exactly one of FlatOp
• FT.CREATE: Type, Dim and DistanceMetric are required for VEC
• FT.CREATE: Type, Dim and DistanceMetric are required for VEC
• FT.CREATE: SCHEMA is required

AI-assisted analysis of go-redis/redis@36d97525cd (2026-08-06). Data as JSON: /data/errors/716266883ae71e0d.json. Report an issue: GitHub.