alibaba/spring-ai-alibaba · error

Feedback list contains non-Message item, ignoring. Type

Error message

Feedback list contains non-Message item, ignoring. Type: {}

What it means

InterruptionHook.apply logs a warning while converting interruption feedback: an element of the feedback list was not a Message instance and is skipped. The hook tolerates mixed input (List<Message>, UserMessage, String) and proceeds with the valid subset.

Solutions

1. Pass only Message instances (or plain String) as interruption feedback
2. Fix the client code that serializes feedback into thread state
3. Ignore safely — the invalid item is skipped, valid ones still apply

When it happens

Trigger: Thrown at spring-ai-alibaba-agent-framework/src/main/java/com/alibaba/cloud/ai/graph/agent/hook/InterruptionHook.java:96 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of alibaba/spring-ai-alibaba@f82da0b50f (2026-09-09). Data as JSON: /api/errors/f107787e1894cc06. Report an issue: GitHub.

Appendix: source

Thrown at spring-ai-alibaba-agent-framework/src/main/java/com/alibaba/cloud/ai/graph/agent/hook/InterruptionHook.java:96

		// it will either see the old value (before removal) or set a new value (after removal)
		// The remove() operation is atomic, preventing race conditions
		Object feedback = agentThreadState.remove(INTERRUPTION_FEEDBACK_KEY);
		
		if (feedback == null) {
			log.debug("No interruption feedback found in state, continue reasoning with no updates.");
			return CompletableFuture.completedFuture(Map.of());
		}

		List<Message> feedbackMessages = new ArrayList<>();
		
		// Check if feedback is List<Message>, UserMessage, or String
		if (feedback instanceof List<?> feedbackList) {
			// Check if all elements in the list are Message instances
			for (Object item : feedbackList) {
				if (item instanceof Message) {
					feedbackMessages.add((Message) item);
				} else {
					log.warn("Feedback list contains non-Message item, ignoring. Type: {}", 
							item != null ? item.getClass().getName() : "null");
				}
			}
			if (feedbackMessages.isEmpty()) {
				log.warn("Feedback list is empty or contains no valid Message instances, stop and wait for more input.");
				return CompletableFuture.completedFuture(Map.of());
			}
		} else if (feedback instanceof UserMessage) {
			feedbackMessages.add((UserMessage) feedback);
		} else if (feedback instanceof String) {
			feedbackMessages.add(new UserMessage((String) feedback));
		} else {
			log.warn("Interruption feedback is neither List<Message>, UserMessage nor String, stop and wait for more input. Type: {}",
					feedback.getClass().getName());
			return CompletableFuture.completedFuture(Map.of());
		}
		
		// Get current messages list

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