spring-projects/spring-ai · info

No complete methods found in the provided complete objects:

Error message

No complete methods found in the provided complete objects: <completeObjects>

What it means

SyncStatelessMcpCompleteProvider scans the supplied completeObjects for methods annotated with @McpComplete (sync/stateless signature, non-reactive return type, bidirectional parameters) and builds SyncCompletionSpecification entries. When the resulting list is empty it logs this warning; nothing is thrown, and the server simply registers zero completion providers. It exists to surface a likely wiring mistake: you handed the provider objects that contain no usable completion methods.

Source

Thrown at mcp/mcp-annotations/src/main/java/org/springframework/ai/mcp/annotation/provider/complete/SyncStatelessMcpCompleteProvider.java:93

					var completeAnnotation = mcpCompleteMethod.getAnnotation(McpComplete.class);
					var completeRef = CompleteAdapter.asCompleteReference(completeAnnotation, mcpCompleteMethod);

					BiFunction<McpTransportContext, CompleteRequest, CompleteResult> methodCallback = SyncStatelessMcpCompleteMethodCallback
						.builder()
						.method(mcpCompleteMethod)
						.bean(completeObject)
						.complete(completeAnnotation)
						.build();

					return new SyncCompletionSpecification(completeRef, methodCallback);
				})
				.toList())
			.flatMap(List::stream)
			.toList();

		if (completeSpecs.isEmpty()) {
			if (logger.isWarnEnabled()) {
				logger.warn("No complete methods found in the provided complete objects: " + this.completeObjects);
			}
		}

		return completeSpecs;
	}

	/**
	 * Returns the methods of the given bean class.
	 * @param bean the bean instance
	 * @return the methods of the bean class
	 */
	protected Method[] doGetClassMethods(Object bean) {
		return bean.getClass().getDeclaredMethods();
	}

}

View on GitHub (pinned to 98a7beda4f)

Solutions

1. Verify each object passed to the provider has at least one public method annotated with @McpComplete with a sync (non-reactive) return type and no bidirectional parameters
2. Move @McpComplete methods into the class itself rather than a superclass or interface (only getDeclaredMethods is scanned)
3. If you use reactive (Mono/Flux) completion methods, use the Async stateless complete provider instead of the sync one
4. Check annotation scanning/import configuration so the beans actually reach the provider (e.g. @McpTool-compatible registration), and confirm the warn is not just an informational log from an optional feature
5. If completions are intentionally unused, remove the completeObjects registration instead of registering empty holders

Example fix

// before
new SyncStatelessMcpCompleteProvider(List.of(new CompletionService())); // no @McpComplete methods inside

// after
class CompletionService {
    @McpComplete(prompt = "code-completion")
    public CompleteResult complete(CompleteRequest request) { ... }
}
new SyncStatelessMcpCompleteProvider(List.of(new CompletionService()));

long found = Arrays.stream(completeObject.getClass().getDeclaredMethods())
    .filter(m -> m.isAnnotationPresent(McpComplete.class))
    .count();
if (found == 0) throw new IllegalStateException(
    completeObject.getClass().getName() + " has no @McpComplete methods");

static boolean hasCompleteMethods(Object bean) {
    return Arrays.stream(bean.getClass().getDeclaredMethods())
        .anyMatch(m -> m.isAnnotationPresent(McpComplete.class));
}

When it happens

Trigger: Calling getCompleteSpecifications() when none of the completeObjects have a method passing all filters: annotated with @McpComplete, non-reactive return type (McpPredicates.filterReactiveReturnTypeMethod), and no bidirectional parameters (filterMethodWithBidirectionalParameters). Also triggered by methods declared on a superclass/interface (only getDeclaredMethods is scanned) or reactive methods accidentally given to the sync provider.

Common situations: Registering a plain Spring bean that forgot @McpComplete annotations; annotating methods on a parent class; passing reactive completion methods to the synchronous stateless provider; using annotation auto-configuration where no completion beans exist at all; bean proxies hiding annotated methods when annotations lack @Inherited-compatible placement.

Understand the failure class

Background: EmptyResultError / "no results found": when an API or scraper succeeds but returns zero rows — this error's family across 9 libraries.

Related errors

• No async complete methods found in the provided complete obj
• No complete methods found in the provided complete objects:
• No elicitation methods found
• Multiple elicitation methods found: <count>
• No elicitation methods found

AI-assisted analysis of spring-projects/spring-ai@98a7beda4f (2026-09-11). Data as JSON: /api/errors/6bbc662d920c2f3a. Report an issue: GitHub.