spring-projects/spring-ai · error · IllegalArgumentException

Either prompt or uri must be provided

Error message

Either prompt or uri must be provided

What it means

Builder-state validation in AbstractMcpCompleteMethodCallback.Builder.validate: a completion callback was registered with neither a prompt reference nor a URI, so there is no completion target to bind the annotated method to.

Solutions

1. Set prompt(...) on the builder for prompt-completion methods
2. Set uri(...) on the builder for resource-completion methods

When it happens

Trigger: Thrown at mcp/mcp-annotations/src/main/java/org/springframework/ai/mcp/annotation/method/complete/AbstractMcpCompleteMethodCallback.java:491 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of spring-projects/spring-ai@98a7beda4f (2026-09-11). Data as JSON: /api/errors/2641ece8cb6af091. Report an issue: GitHub.

Appendix: source

Thrown at mcp/mcp-annotations/src/main/java/org/springframework/ai/mcp/annotation/method/complete/AbstractMcpCompleteMethodCallback.java:491

		@SuppressWarnings("unchecked")
		public T uriTemplateManagerFactory(McpUriTemplateManagerFactory uriTemplateManagerFactory) {
			this.uriTemplateManagerFactory = uriTemplateManagerFactory;
			return (T) this;
		}

		/**
		 * Validate the builder state.
		 * @throws IllegalArgumentException if the builder state is invalid
		 */
		protected void validate() {
			if (this.method == null) {
				throw new IllegalArgumentException("Method must not be null");
			}
			if (this.bean == null) {
				throw new IllegalArgumentException("Bean must not be null");
			}
			if ((this.prompt == null || this.prompt.isEmpty()) && (this.uri == null || this.uri.isEmpty())) {
				throw new IllegalArgumentException("Either prompt or uri must be provided");
			}
			if ((this.prompt != null && !this.prompt.isEmpty()) && (this.uri != null && !this.uri.isEmpty())) {
				throw new IllegalArgumentException("Only one of prompt or uri can be provided");
			}
			if (this.uriTemplateManagerFactory == null) {
				this.uriTemplateManagerFactory = new DefaultMcpUriTemplateManagerFactory();
			}
		}

		/**
		 * Build the callback.
		 * @return A new callback instance
		 */
		public abstract R build();

	}

}

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