dotnet/efcore · error · NotSupportedException

Creating a container with full-text search or vector propert

Error message

Creating a container with full-text search or vector properties inside a collection navigation is currently not supported using EF Core; path: '{path}'. Create the container using other means (e.g. Microsoft.Azure.Cosmos SDK).

What it means

EF Core cannot create a Cosmos container that includes full-text search or vector embedding policies inside a non-unique owned navigation (a collection of owned entities). The Cosmos SDK requires vector/full-text policy paths to be deterministic, and collection-owned entities map to array paths (/Collection/[]), which the policy does not support for these feature types. The check is at CosmosClientWrapper.cs:420-424 during path building.

Source

Thrown at src/EFCore.Cosmos/Storage/Internal/CosmosClientWrapper.cs:422

                var complexProperty = complexType.ComplexProperty;
                AppendTypePathFromRoot(builder, complexProperty.DeclaringType);
                AppendComplexPropertySegment(builder, complexProperty);
                break;
            }
            case IReadOnlyEntityType entityType when entityType.IsOwned():
            {
                var ownership = entityType.FindOwnership()!;
                var containingPropertyName = ownership.GetNavigation(pointsToPrincipal: false)!
                        .TargetEntityType.GetContainingPropertyName()
                    ?? throw new UnreachableException("Containing property name should not be null for owned entity types.");

                AppendTypePathFromRoot(builder, ownership.PrincipalEntityType);
                builder.Append('/');
                AppendEscapedPathSegment(builder, containingPropertyName);

                if (!ownership.IsUnique)
                {
                    throw new NotSupportedException(
                        CosmosStrings.CreatingContainerWithFullTextOrVectorOnCollectionNotSupported(builder.ToString()));
                }

                break;
            }
        }
    }

    private static void AppendComplexPropertySegment(StringBuilder builder, IReadOnlyComplexProperty complexProperty)
    {
        builder.Append('/');
        AppendEscapedPathSegment(builder, complexProperty.GetJsonPropertyName());
        if (complexProperty.IsCollection)
        {
            builder.Append("/[]");
        }
    }

View on GitHub (pinned to dbf9771522)

Solutions

1. Move the vector/full-text property to a document-root entity type instead of an owned collection element. Model the collection as a separate entity with its own container or as a root document.
2. Create the container manually using the Microsoft.Azure.Cosmos SDK directly, bypassing EF Core's EnsureCreated, if your schema genuinely requires this structure.
3. Restructure so the owned relationship is unique (OwnsOne) rather than a collection, if semantically appropriate.

Example fix

// before
modelBuilder.Entity<Order>()
    .OwnsMany(o => o.Items, ib =>
    {
        ib.Property(i => i.Embedding).IsVectorProperty(DistanceFunction.Cosine, 128);
    });

// after — make Item a root entity in its own container
modelBuilder.Entity<Order>().OwnsMany(o => o.Items, ib => { /* no vector config */ });
modelBuilder.Entity<OrderItem>()
    .Property(i => i.Embedding)
    .IsVectorProperty(DistanceFunction.Cosine, 128);
// or create the container via the Cosmos SDK directly

// Validate that no owned collection element has vector or full-text properties.
foreach (var entityType in model.GetEntityTypes())
{
    var ownership = entityType.FindOwnership();
    if (ownership is not null && !ownership.IsUnique) // owned collection
    {
        foreach (var property in entityType.GetProperties())
        {
            if (property.FindTypeMapping() is CosmosVectorTypeMapping
                || property.GetIsFullTextSearchEnabled() == true)
                throw new InvalidOperationException($"Owned collection element {entityType.DisplayName()} has vector/full-text property {property.Name}.");
        }
    }
}

When it happens

Trigger: Using OwnsMany with an owned entity that has a vector property (IsVectorProperty) or a full-text property (IsFullTextSearch), then calling EnsureCreatedAsync/EnsureCreated to create the container. The path builder hits the non-unique ownership and throws NotSupportedException.

Common situations: Modeling an owned collection (e.g., Order.OwnsMany(o => o.Tags)) where each tag has an embedding for similarity search. Embedding search over items in a collection navigation. Full-text search inside a nested collection.

Related errors

• A vector index on '{entityType}' is defined over properties
• A full-text index on '{entityType}' is defined over multiple
• The requested configuration is not stored in the read-optimi
• The value '{value}' provided for argument '{argumentName}' m
• Ordering based on scoring function is not supported inside '

AI-assisted analysis of dotnet/efcore@dbf9771522 (2026-08-06). Data as JSON: /api/errors/71c48189407ff5ff. Report an issue: GitHub.