spring-projects/spring-ai · error · RuntimeException

Unsupported value type for IN condition. Only supports…

Error message

Unsupported value type for IN condition. Only supports non-empty List of String or Number

What it means

buildInCondition requires the IN operand to be a non-empty List; passing any other value type (single scalar, null, map) or an empty List throws this RuntimeException. Qdrant's matchValues needs a collection of values to match against.

Solutions

1. Wrap scalar values in a List: in("genre", List.of("drama")).
2. Skip building the IN expression (or the whole filter) when the values collection is empty.
3. Coerce single values via Collections.singletonList before passing.
4. Guard call sites: if (values != null && !values.isEmpty()) { filter = Filter.builder().in(...) }.

Example fix

// before
Filter.builder().in("genre", selectedGenres).build(); // selectedGenres may be empty
// after
if (selectedGenres != null && !selectedGenres.isEmpty()) {
    filter = Filter.builder().in("genre", selectedGenres).build();
}

static boolean canBuildIn(Object operand) {
    return operand instanceof List<?> l && !l.isEmpty();
}
// usage: only add the IN expression when canBuildIn(values) is true

static boolean isNonEmptyList(Object v) {
    return v instanceof List<?> l && !l.isEmpty();
}

try {
    vectorStore.similaritySearch(req);
} catch (RuntimeException ex) {
    if (ex.getMessage() != null && ex.getMessage().contains("Unsupported value type for IN condition")) {
        log.warn("IN filter skipped: operand was not a non-empty list");
        return vectorStore.similaritySearch(reqWithoutIn);
    }
    throw ex;
}

When it happens

Trigger: Filter.builder().in("genre", "drama").build() (scalar instead of list) or in("genre", List.of()) (empty list) passed to the Qdrant vector store.

Common situations: Dynamic filter building where the values collection is optional and empty when no filters are selected — callers pass an empty list instead of omitting the expression entirely.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• Unsupported value in IN value list. Only supports String or…
• Invalid value type for EQ. Can either be a string or Number
• Invalid value type for NEQ. Can either be a string or Number
• Non AND/OR/NOT expression must have Value right argument!
• Unsupported expression type:

AI-assisted analysis of spring-projects/spring-ai@98a7beda4f (2026-09-11). Data as JSON: /api/errors/ea9a2e8aadd9420c. Report an issue: GitHub.

Appendix: source

Thrown at vector-stores/spring-ai-qdrant-store/src/main/java/org/springframework/ai/vectorstore/qdrant/QdrantFilterExpressionConverter.java:189

				for (Object valueObj : valueList) {
					stringValues.add(valueObj.toString());
				}
				return io.qdrant.client.ConditionFactory.matchKeywords(identifier, stringValues);
			}
			else if (firstValue instanceof Number) {
				// If the first value is a number, then all values should be numbers
				List<Long> longValues = new ArrayList<>();
				for (Object valueObj : valueList) {
					Long longValue = Long.parseLong(valueObj.toString());
					longValues.add(longValue);
				}
				return io.qdrant.client.ConditionFactory.matchValues(identifier, longValues);
			}
			else {
				throw new RuntimeException("Unsupported value in IN value list. Only supports String or Number");
			}
		}
		throw new RuntimeException(
				"Unsupported value type for IN condition. Only supports non-empty List of String or Number");

	}

	protected Condition buildNInCondition(Key key, Value value) {
		if (value.value() instanceof List valueList && !valueList.isEmpty()) {
			Object firstValue = valueList.get(0);
			String identifier = doKey(key);

			if (firstValue instanceof String) {
				// If the first value is a string, then all values should be strings
				List<String> stringValues = new ArrayList<>();
				for (Object valueObj : valueList) {
					stringValues.add(valueObj.toString());
				}
				return io.qdrant.client.ConditionFactory.matchExceptKeywords(identifier, stringValues);
			}
			else if (firstValue instanceof Number) {

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