The Java client (both v5.5.0 and v6.0.0) does not validate reserved property names

[mironnn]

TL;DR

The Java client (both v5.5.0 and v6.0.0) does not validate reserved property names like id, _id, or _additional at collection creation time, allowing schemas that may cause unexpected behavior. Should the client add validation like the Python client does?

Question

Should the Java client add validation for reserved property names?

Description

According to Weaviate documentation, the following property names are reserved and cannot be used:

• _additional
• id
• _id

However, both Java v5 and v6 clients do not validate these restrictions at the client side. This allows developers to create collection schemas that may cause issues, without any warning or error during schema creation.

Current Behavior

Java v5 (5.5.0)

The Java v5 client successfully creates collections with reserved property names in nested objects:

List<Property.NestedProperty> nestedProps = Arrays.asList(
    Property.NestedProperty.builder()
        .name("id")  // Reserved word - no validation error
        .dataType(Arrays.asList("text"))
        .build(),
    Property.NestedProperty.builder()
        .name("_additional")  // Reserved word - no validation error
        .dataType(Arrays.asList("text"))
        .build()
);

Property property = Property.builder()
    .name("metadata")
    .dataType(Arrays.asList("object"))
    .nestedProperties(nestedProps)
    .build();

Result: Collection created successfully without any client-side validation.

Java v6 (6.0.0)

The Java v6 client (with new functional API) also allows reserved names:

CollectionHandle<Map<String, Object>> collection = client.collections.create(
    className,
    col -> col.properties(
        Property.object("metadata", obj -> obj
            .nestedProperties(
                Property.text("id"),  // Reserved word - no validation error
                Property.text("_additional")  // Reserved word - no validation error
            )
        )
    )
);

Result: Collection created successfully without any client-side validation.

Comparison with Other Clients

Client	Version	Validates Reserved Words?	Behavior
Python	4.19.2	✅ Yes	Blocks reserved names via Pydantic validation
Go v5	5.6.0	❌ No	Allows all property names
Java v5	5.5.0	❌ No	Allows all property names
Java v6	6.0.0	❌ No	Allows all property names

Java v6 Test

CollectionHandle<Map<String, Object>> collection = client.collections.create(
    "TestNested",
    col -> col.properties(
        Property.object("metadata", obj -> obj
            .nestedProperties(
                Property.text("id")  // Should this be validated?
            )
        )
    )
);
// No error - collection created successfully

Environment

• Java v5 Client: io.weaviate:client:5.5.0
• Java v6 Client: io.weaviate:client6:6.0.0
• Java Version: 17
• Weaviate Server: 1.34.0

Related Issues

Link for issue in python client
Link for issue in go client