Can't make native image support local STDIO MCP server

[asm0dey]

Please do a quick search on GitHub issues first, there might be already a duplicate issue for the one you are about to create.
If the bug is trivial, just go ahead and create the issue. Otherwise, please take a few moments and fill in the following sections:

Bug description
When I call ./gradlew nativeCompile on this repository: https://github.com/asm0dey/git-mcp-spring/, I'm not getting any errors, however, when I'm trying to use the resulting binary as an mcp in LMStudio, it doesn't seem to work.
The usual Java build works there correctly

Environment
Linux amd64
Spring AI 2.0.0-SNAPSHOT
Spring Boot 4.0.1-SNAPSHOT
Java 25.0.1.r25-nik
Please provide as many details as possible: Spring AI version, Java version, which vector store you use if any, etc

Visually, the same behaviour reproduces on Spring Boot 3 and the latest stable version of Spring AI

Steps to reproduce
In LMStudio, add the following block to mcp:

    "git": {
      "command": "<path>/git-mcp-spring/build/native/nativeCompile/git-mcp-spring"
    }

Open a new chat, turn on the MCP server, and try to use it

OTOH, if you add it as:

    "git": {
      "command": "<path>/java",
    "args": {
      "-jar",
      "<path>/git-mcp-spring/build/libs/git-mcp-spring-0.0.1-SNAPSHOT.jar"
    }

It works roughly as expected - at least it can use the declared tools

Expected behavior
Tools should be available OOTB

Minimal Complete Reproducible example
Please provide a failing test or a minimal complete verifiable example that reproduces the issue.
Bug reports that are reproducible will take priority in resolution over reports that are not reproducible.

[joshlong]

hi - i took ur code, moved it to a simplified maven build so i could focus on what it was doing and put it here https://github.com/joshlong-attic/git-mcp-spring-and-graalvm

i added some graalvm native hints for the JGit library you're using and for the various types you created to be serialized. it seems to be fixed when i do things like use the git open and git logs equivalents from teh MCP inspector

#!/usr/bin/env bash
npx @modelcontextprotocol/inspector

i saw that you have a .json file with graalvm native image hints. but these are string-ly typed and fragile, and anyway Spring Boot's component model will find most of those for you anyway. the only custom code i had to write was to add a bean method and the class for that bean method. (shown below)

it's an instance of Spring AOT's BeanFactoryInitializationAotProcessor. In it, you get a chance to visit the Spring components as they're initializing and inspect them and their types. In this case, i used the chance to figure out what packages were in Spring Boot's "auto configuration" path. Then you cna do whatever you want to inspect them and ask questions about them with reflection. I wanted to discover all the code that used records or enums and register for reflection.

to discover these beans, i used another neat trick: the Spring Framework class ClassPathScanningCandidateComponentProvider can be used to discover types (using whatever predicate u want) in a given package. so i basically just had it told me about all the types in certain packages and then inspected them to discover if they are enums or records. If so, i added them to a collection and then programatically registered 'hints' that will get translated during the compilation into .json config values.

	@Bean
	static GitMcpBeanFactoryInitializationAotProcessor gitMcpBeanFactoryInitializationAotProcessor() {
		return new GitMcpBeanFactoryInitializationAotProcessor();
	}

	static class GitMcpBeanFactoryInitializationAotProcessor implements BeanFactoryInitializationAotProcessor {

		private final Logger log = LoggerFactory.getLogger(this.getClass());

		@Override
		public BeanFactoryInitializationAotContribution processAheadOfTime(
				ConfigurableListableBeanFactory beanFactory) {
			var typesForReflection = new HashSet<Class<?>>();
			var rootPackages = new HashSet<>(AutoConfigurationPackages.get(beanFactory));
			rootPackages.add("org.eclipse.jgit");

			for (var packageName : rootPackages) {
				for (var beanDefinition : this.find(packageName)) {
					var clzz = this.classFor(beanDefinition);
					if (clzz != null) {
						if (clzz.isEnum() || clzz.isRecord())
							typesForReflection.add(clzz);
					}
				}
			}

			return (ctx, code) -> {
				var reflection = ctx.getRuntimeHints().reflection();
				for (var clazz : typesForReflection) {
					log.info("registering {} for reflection.", clazz.getName());
					reflection.registerType(clazz, MemberCategory.values());
				}
			};
		}

		private Set<BeanDefinition> find(String pgk) {
			var cpp = new ClassPathScanningCandidateComponentProvider(false) {
				@Override
				protected boolean isCandidateComponent(MetadataReader metadataReader) throws IOException {
					return true;
				}

				@Override
				protected boolean isCandidateComponent(AnnotatedBeanDefinition beanDefinition) {
					return true;
				}
			};
			return cpp.findCandidateComponents(pgk);
		}

		private Class<?> classFor(BeanDefinition beanDefinition) {
			try {
				return Class.forName(beanDefinition.getBeanClassName());
			}
			catch (Throwable e) {
				// don't care..
			}
			return null;
		}

	}

i then ran the script i wrote (native.sh) and waited and then plugged in the full path to the native binary into the MCP inspector and it seemed happy. i dont know how to test all the endpoints so i'll leave that to you. Usefully, you get some pretty descriptive errors in the MCP inspector from Spring Boot if you get an exception.

i hope this helps and happy holidays!

[asm0dey]

Thank you so much, @joshlong! This is any amazing analysis and set of advises!

I guess this is resolved now then, obviously it was not any issue with spring ai, but with my code