Package org.springframework.ai.mcp

Class AsyncMcpToolCallbackProvider

java.lang.Object
org.springframework.ai.mcp.AsyncMcpToolCallbackProvider
All Implemented Interfaces:
ToolCallbackProvider
public class AsyncMcpToolCallbackProvider extends Object implements ToolCallbackProvider
Implementation of ToolCallbackProvider that discovers and provides MCP tools asynchronously from one or more MCP servers.

This class acts as a tool provider for Spring AI, automatically discovering tools from multiple MCP servers and making them available as Spring AI tools. It:

  • Connects to MCP servers through async clients
  • Lists and retrieves available tools from each server asynchronously
  • Creates AsyncMcpToolCallback instances for each discovered tool
  • Validates tool names to prevent duplicates across all servers

Example usage with a single client: 


 McpAsyncClient mcpClient = // obtain MCP client
 ToolCallbackProvider provider = new AsyncMcpToolCallbackProvider(mcpClient);

 // Get all available tools
 ToolCallback[] tools = provider.getToolCallbacks();
Example usage with multiple clients: 

 List<McpAsyncClient> mcpClients = // obtain multiple MCP clients
 ToolCallbackProvider provider = new AsyncMcpToolCallbackProvider(mcpClients);

 // Get tools from all clients
 ToolCallback[] tools = provider.getToolCallbacks();

 // Or use the reactive API
 Flux<ToolCallback> toolsFlux = AsyncMcpToolCallbackProvider.asyncToolCallbacks(mcpClients);
Since:
1.0.0
Author:
Christian Tzolov
See Also:

  • Constructor Details

    • AsyncMcpToolCallbackProvider

      public AsyncMcpToolCallbackProvider(List<io.modelcontextprotocol.client.McpAsyncClient> mcpClients)
      Creates a new AsyncMcpToolCallbackProvider instance with a list of MCP clients.
      Parameters:
      mcpClients - the list of MCP clients to use for discovering tools. Each client typically connects to a different MCP server, allowing tool discovery from multiple sources.
      Throws:
      IllegalArgumentException - if mcpClients is null

    • AsyncMcpToolCallbackProvider

      public AsyncMcpToolCallbackProvider(io.modelcontextprotocol.client.McpAsyncClient... mcpClients)

  • Method Details

    • getToolCallbacks

      public ToolCallback[] getToolCallbacks()
      Discovers and returns all available tools from the configured MCP servers.

      This method:

      1. Retrieves the list of tools from each MCP server asynchronously
      2. Creates a AsyncMcpToolCallback for each discovered tool
      3. Validates that there are no duplicate tool names across all servers

      Note: While the underlying tool discovery is asynchronous, this method blocks until all tools are discovered from all servers.

      Specified by:
      getToolCallbacks in interface ToolCallbackProvider
      Returns:
      an array of tool callbacks, one for each discovered tool
      Throws:
      IllegalStateException - if duplicate tool names are found

    • asyncToolCallbacks

      public static reactor.core.publisher.Flux<ToolCallback> asyncToolCallbacks(List<io.modelcontextprotocol.client.McpAsyncClient> mcpClients)
      Creates a reactive stream of tool callbacks from multiple MCP clients.

      This utility method provides a reactive way to work with tool callbacks from multiple MCP clients in a single operation. It:

      1. Takes a list of MCP clients as input
      2. Creates a provider instance to manage all clients
      3. Retrieves tools from all clients asynchronously
      4. Combines them into a single reactive stream
      5. Ensures there are no naming conflicts between tools from different clients

      Unlike getToolCallbacks(), this method provides a fully reactive way to work with tool callbacks, making it suitable for non-blocking applications. Any errors during tool discovery will be propagated through the returned Flux.

      Parameters:
      mcpClients - the list of MCP clients to create callbacks from
      Returns:
      a Flux of tool callbacks from all provided clients