This version is still in development and is not considered stable yet. For the latest snapshot version, please use Spring AI 1.0.1! |
Stateless MCP Servers
Stateless MCP servers are designed for simplified deployments where session state is not maintained between requests. These servers are ideal for microservices architectures and cloud-native deployments.
Set the spring.ai.mcp.server.protocol=STATELESS property
|
Use the Streamable-HTTP clients to connect to the stateless servers. |
The stateless servers don’t support message requests to the MCP client (e.g., elicitation, sampling, ping). |
Stateless WebMVC Server
Use the spring-ai-starter-mcp-server-webmvc
dependency:
<dependency>
<groupId>org.springframework.ai</groupId>
<artifactId>spring-ai-starter-mcp-server-webmvc</artifactId>
</dependency>
and set the spring.ai.mcp.server.protocol
property to STATLESS
.
spring.ai.mcp.server.protocol=STATLESS
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Stateless operation with Spring MVC transport
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No session state management
-
Simplified deployment model
-
Optimized for cloud-native environments
Stateless WebFlux Server
Use the spring-ai-starter-mcp-server-webflux
dependency:
<dependency>
<groupId>org.springframework.ai</groupId>
<artifactId>spring-ai-starter-mcp-server-webflux</artifactId>
</dependency>
and set the spring.ai.mcp.server.protocol
property to STATLESS
.
-
Reactive stateless operation with WebFlux transport
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No session state management
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Non-blocking request processing
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Optimized for high-throughput scenarios
Configuration Properties
Common Properties
All Common properties are prefixed with spring.ai.mcp.server
:
Property | Description | Default |
---|---|---|
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Enable/disable the stateless MCP server |
|
|
MCP server protocol |
Must be set to |
|
Enable/disable the conversion of Spring AI ToolCallbacks into MCP Tool specs |
|
|
Server name for identification |
|
|
Server version |
|
|
Optional instructions for client interaction |
|
|
Server type (SYNC/ASYNC) |
|
|
Enable/disable resource capabilities |
|
|
Enable/disable tool capabilities |
|
|
Enable/disable prompt capabilities |
|
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Enable/disable completion capabilities |
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|
Response MIME type per tool name |
|
|
Request timeout duration |
|
Features and Capabilities
The MCP Server Boot Starter allows servers to expose tools, resources, and prompts to clients. It automatically converts custom capability handlers registered as Spring beans to sync/async specifications based on the server type:
Tools
Allows servers to expose tools that can be invoked by language models. The MCP Server Boot Starter provides:
-
Change notification support
-
Spring AI Tools are automatically converted to sync/async specifications based on the server type
-
Automatic tool specification through Spring beans:
@Bean
public ToolCallbackProvider myTools(...) {
List<ToolCallback> tools = ...
return ToolCallbackProvider.from(tools);
}
or using the low-level API:
@Bean
public List<McpStatelessServerFeatures.SyncToolSpecification> myTools(...) {
List<McpStatelessServerFeatures.SyncToolSpecification> tools = ...
return tools;
}
The auto-configuration will automatically detect and register all tool callbacks from:
-
Individual
ToolCallback
beans -
Lists of
ToolCallback
beans -
ToolCallbackProvider
beans
Tools are de-duplicated by name, with the first occurrence of each tool name being used.
You can disable the automatic detection and registration of all tool callbacks by setting the tool-callback-converter to false .
|
Tool Context Support is not applicable for stateless servers. |
Resources
Provides a standardized way for servers to expose resources to clients.
-
Static and dynamic resource specifications
-
Optional change notifications
-
Support for resource templates
-
Automatic conversion between sync/async resource specifications
-
Automatic resource specification through Spring beans:
@Bean
public List<McpStatelessServerFeatures.SyncResourceSpecification> myResources(...) {
var systemInfoResource = new McpSchema.Resource(...);
var resourceSpecification = new McpStatelessServerFeatures.SyncResourceSpecification(systemInfoResource, (context, request) -> {
try {
var systemInfo = Map.of(...);
String jsonContent = new ObjectMapper().writeValueAsString(systemInfo);
return new McpSchema.ReadResourceResult(
List.of(new McpSchema.TextResourceContents(request.uri(), "application/json", jsonContent)));
}
catch (Exception e) {
throw new RuntimeException("Failed to generate system info", e);
}
});
return List.of(resourceSpecification);
}
Prompts
Provides a standardized way for servers to expose prompt templates to clients.
-
Change notification support
-
Template versioning
-
Automatic conversion between sync/async prompt specifications
-
Automatic prompt specification through Spring beans:
@Bean
public List<McpStatelessServerFeatures.SyncPromptSpecification> myPrompts() {
var prompt = new McpSchema.Prompt("greeting", "A friendly greeting prompt",
List.of(new McpSchema.PromptArgument("name", "The name to greet", true)));
var promptSpecification = new McpStatelessServerFeatures.SyncPromptSpecification(prompt, (context, getPromptRequest) -> {
String nameArgument = (String) getPromptRequest.arguments().get("name");
if (nameArgument == null) { nameArgument = "friend"; }
var userMessage = new PromptMessage(Role.USER, new TextContent("Hello " + nameArgument + "! How can I assist you today?"));
return new GetPromptResult("A personalized greeting message", List.of(userMessage));
});
return List.of(promptSpecification);
}
Completion
Provides a standardized way for servers to expose completion capabilities to clients.
-
Support for both sync and async completion specifications
-
Automatic registration through Spring beans:
@Bean
public List<McpStatelessServerFeatures.SyncCompletionSpecification> myCompletions() {
var completion = new McpStatelessServerFeatures.SyncCompletionSpecification(
new McpSchema.PromptReference(
"ref/prompt", "code-completion", "Provides code completion suggestions"),
(exchange, request) -> {
// Implementation that returns completion suggestions
return new McpSchema.CompleteResult(List.of("python", "pytorch", "pyside"), 10, true);
}
);
return List.of(completion);
}
Usage Examples
Stateless Server Configuration
spring:
ai:
mcp:
server:
protocol: STATELESS
name: stateless-mcp-server
version: 1.0.0
type: ASYNC
instructions: "This stateless server is optimized for cloud deployments"
streamable-http:
mcp-endpoint: /api/mcp
Creating a Spring Boot Application with MCP Server
@Service
public class WeatherService {
@Tool(description = "Get weather information by city name")
public String getWeather(String cityName) {
// Implementation
}
}
@SpringBootApplication
public class McpServerApplication {
private static final Logger logger = LoggerFactory.getLogger(McpServerApplication.class);
public static void main(String[] args) {
SpringApplication.run(McpServerApplication.class, args);
}
@Bean
public ToolCallbackProvider weatherTools(WeatherService weatherService) {
return MethodToolCallbackProvider.builder().toolObjects(weatherService).build();
}
}
The auto-configuration will automatically register the tool callbacks as MCP tools. You can have multiple beans producing ToolCallbacks, and the auto-configuration will merge them.