McpServer (solon-ai-mcp 3.5.2-RC API)

public interface McpServer

Factory class for creating Model Context Protocol (MCP) servers. MCP servers expose tools, resources, and prompts to AI models through a standardized interface.

This class serves as the main entry point for implementing the server-side of the MCP specification. The server's responsibilities include:

Exposing tools that models can invoke to perform actions
Providing access to resources that give models context
Managing prompt templates for structured model interactions
Handling client connections and requests
Implementing capability negotiation

Thread Safety: Both synchronous and asynchronous server implementations are thread-safe. The synchronous server processes requests sequentially, while the asynchronous server can handle concurrent requests safely through its reactive programming model.

Error Handling: The server implementations provide robust error handling through the McpError class. Errors are properly propagated to clients while maintaining the server's stability. Server implementations should use appropriate error codes and provide meaningful error messages to help diagnose issues.

The class provides factory methods to create either:

McpAsyncServer for non-blocking operations with reactive responses
McpSyncServer for blocking operations with direct responses

Example of creating a basic synchronous server:


 McpServer.sync(transportProvider)
     .serverInfo("my-server", "1.0.0")
     .tool(new Tool("calculator", "Performs calculations", schema),
           (exchange, args) -> new CallToolResult("Result: " + calculate(args)))
     .build();

Example of creating a basic asynchronous server:


 McpServer.async(transportProvider)
     .serverInfo("my-server", "1.0.0")
     .tool(new Tool("calculator", "Performs calculations", schema),
           (exchange, args) -> Mono.fromSupplier(() -> calculate(args))
               .map(result -> new CallToolResult("Result: " + result)))
     .build();

Example with comprehensive asynchronous configuration:


 McpServer.async(transportProvider)
     .serverInfo("advanced-server", "2.0.0")
     .capabilities(new ServerCapabilities(...))
     // Register tools
     .tools(
         McpServerFeatures.AsyncToolSpecification.builder()
 			.tool(calculatorTool)
   	    .callTool((exchange, args) -> Mono.fromSupplier(() -> calculate(args.arguments()))
                 .map(result -> new CallToolResult("Result: " + result))))
.         .build(),
         McpServerFeatures.AsyncToolSpecification.builder()
 	        .tool((weatherTool)
          .callTool((exchange, args) -> Mono.fromSupplier(() -> getWeather(args.arguments()))
                 .map(result -> new CallToolResult("Weather: " + result))))
          .build()
     )
     // Register resources
     .resources(
         new McpServerFeatures.AsyncResourceSpecification(fileResource,
             (exchange, req) -> Mono.fromSupplier(() -> readFile(req))
                 .map(ReadResourceResult::new)),
         new McpServerFeatures.AsyncResourceSpecification(dbResource,
             (exchange, req) -> Mono.fromSupplier(() -> queryDb(req))
                 .map(ReadResourceResult::new))
     )
     // Add resource templates
     .resourceTemplates(
         new ResourceTemplate("file://{path}", "Access files"),
         new ResourceTemplate("db://{table}", "Access database")
     )
     // Register prompts
     .prompts(
         new McpServerFeatures.AsyncPromptSpecification(analysisPrompt,
             (exchange, req) -> Mono.fromSupplier(() -> generateAnalysisPrompt(req))
                 .map(GetPromptResult::new)),
         new McpServerFeatures.AsyncPromptRegistration(summaryPrompt,
             (exchange, req) -> Mono.fromSupplier(() -> generateSummaryPrompt(req))
                 .map(GetPromptResult::new))
     )
     .build();

Author:: Christian Tzolov, Dariusz Jędrzejczyk, Jihoon Kim
See Also:: McpAsyncServer, McpSyncServer, McpServerTransportProvider

Nested Class Summary

Nested Classes
Modifier and Type	Interface and Description
`static class`	`McpServer.AsyncSpecification<S extends McpServer.AsyncSpecification<S>>` Asynchronous server specification.
`static class`	`McpServer.SingleSessionAsyncSpecification`
`static class`	`McpServer.SingleSessionSyncSpecification`
`static class`	`McpServer.StatelessAsyncSpecification`
`static class`	`McpServer.StatelessSyncSpecification`
`static class`	`McpServer.StreamableServerAsyncSpecification`
`static class`	`McpServer.StreamableSyncSpecification`
`static class`	`McpServer.SyncSpecification<S extends McpServer.SyncSpecification<S>>` Synchronous server specification.

Field Summary

Fields
Modifier and Type Field and Description

static McpSchema.Implementation DEFAULT_SERVER_INFO

Fields
Modifier and Type	Field and Description
`static McpSchema.Implementation`	`DEFAULT_SERVER_INFO`

Method Summary

All Methods Static Methods Default Methods
Modifier and Type	Method and Description
`static McpServer.AsyncSpecification<?>`	`async(McpServerTransportProvider transportProvider)` Starts building an asynchronous MCP server that provides non-blocking operations.
`static McpServer.StatelessAsyncSpecification`	`async(McpStatelessServerTransport transport)` Starts building an asynchronous MCP server that provides non-blocking operations.
`static McpServer.AsyncSpecification<?>`	`async(McpStreamableServerTransportProvider transportProvider)` Starts building an asynchronous MCP server that provides non-blocking operations.
`static McpServer.SingleSessionSyncSpecification`	`sync(McpServerTransportProvider transportProvider)` Starts building a synchronous MCP server that provides blocking operations.
`static McpServer.StatelessSyncSpecification`	`sync(McpStatelessServerTransport transport)` Starts building a synchronous MCP server that provides blocking operations.
`static McpServer.StreamableSyncSpecification`	`sync(McpStreamableServerTransportProvider transportProvider)` Starts building a synchronous MCP server that provides blocking operations.

- Field Detail
  - DEFAULT_SERVER_INFO
```
static final McpSchema.Implementation DEFAULT_SERVER_INFO
```
- Method Detail
  - sync
```
static McpServer.SingleSessionSyncSpecification sync(McpServerTransportProvider transportProvider)
```
    Starts building a synchronous MCP server that provides blocking operations. Synchronous servers block the current Thread's execution upon each request before giving the control back to the caller, making them simpler to implement but potentially less scalable for concurrent operations.
    
    Parameters:
    
    transportProvider - The transport layer implementation for MCP communication.
    
    Returns:
    
    A new instance of McpServer.SyncSpecification for configuring the server.
  - async
```
static McpServer.AsyncSpecification<?> async(McpServerTransportProvider transportProvider)
```
    Starts building an asynchronous MCP server that provides non-blocking operations. Asynchronous servers can handle multiple requests concurrently on a single Thread using a functional paradigm with non-blocking server transports, making them more scalable for high-concurrency scenarios but more complex to implement.
    
    Parameters:
    
    transportProvider - The transport layer implementation for MCP communication.
    
    Returns:
    
    A new instance of McpServer.AsyncSpecification for configuring the server.
  - sync
```
static McpServer.StreamableSyncSpecification sync(McpStreamableServerTransportProvider transportProvider)
```
    Starts building a synchronous MCP server that provides blocking operations. Synchronous servers block the current Thread's execution upon each request before giving the control back to the caller, making them simpler to implement but potentially less scalable for concurrent operations.
    
    Parameters:
    
    transportProvider - The transport layer implementation for MCP communication.
    
    Returns:
    
    A new instance of McpServer.SyncSpecification for configuring the server.
  - async
```
static McpServer.AsyncSpecification<?> async(McpStreamableServerTransportProvider transportProvider)
```
    Starts building an asynchronous MCP server that provides non-blocking operations. Asynchronous servers can handle multiple requests concurrently on a single Thread using a functional paradigm with non-blocking server transports, making them more scalable for high-concurrency scenarios but more complex to implement.
    
    Parameters:
    
    transportProvider - The transport layer implementation for MCP communication.
    
    Returns:
    
    A new instance of McpServer.AsyncSpecification for configuring the server.
  - async
```
static McpServer.StatelessAsyncSpecification async(McpStatelessServerTransport transport)
```
    Starts building an asynchronous MCP server that provides non-blocking operations. Asynchronous servers can handle multiple requests concurrently on a single Thread using a functional paradigm with non-blocking server transports, making them more scalable for high-concurrency scenarios but more complex to implement.
    
    Parameters:
    
    transport - The transport layer implementation for MCP communication.
    
    Returns:
    
    A new instance of McpServer.AsyncSpecification for configuring the server.
  - sync
```
static McpServer.StatelessSyncSpecification sync(McpStatelessServerTransport transport)
```
    Starts building a synchronous MCP server that provides blocking operations. Synchronous servers block the current Thread's execution upon each request before giving the control back to the caller, making them simpler to implement but potentially less scalable for concurrent operations.
    
    Parameters:
    
    transport - The transport layer implementation for MCP communication.
    
    Returns:
    
    A new instance of McpServer.SyncSpecification for configuring the server.

Interface McpServer

Nested Class Summary

Field Summary

Method Summary

Field Detail

DEFAULT_SERVER_INFO

Method Detail

sync

async

sync

async

async

sync