Add McpApp, ProxyApp, middleware, context features, and sampling support

.gitignore

@@ -1 +1,39 @@
+# Build directories
 build*/
+out/
+cmake-build-*/
+
+# IDE files
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# Compiled objects
+*.o
+*.obj
+*.a
+*.lib
+*.so
+*.dll
+*.dylib
+
+# Executables
+*.exe
+*.out
+
+# CMake generated
+CMakeCache.txt
+CMakeFiles/
+cmake_install.cmake
+Makefile
+compile_commands.json
+
+# Package managers
+vcpkg_installed/
+_deps/
+
+# OS files
+.DS_Store
+Thumbs.db

CMakeLists.txt

@@ -15,9 +15,12 @@ option(FASTMCPP_ENABLE_LOCAL_WS_TEST "Enable local WebSocket server test (depend
 add_library(fastmcpp_core
     src/types.cpp
     src/util/schema_build.cpp
+    src/app.cpp
+    src/proxy.cpp
     src/mcp/handler.cpp
     src/resources/resource.cpp
     src/resources/manager.cpp
+    src/resources/template.cpp
     src/prompts/prompt.cpp
     src/prompts/manager.cpp
     src/tools/tool.cpp
@@ -142,6 +145,18 @@ if(FASTMCPP_BUILD_TESTS)
   target_link_libraries(fastmcpp_tools PRIVATE fastmcpp_core)
   add_test(NAME fastmcpp_tools COMMAND fastmcpp_tools)
 
+  add_executable(fastmcpp_tools_transform tests/tools/test_tool_transform.cpp)
+  target_link_libraries(fastmcpp_tools_transform PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_tools_transform COMMAND fastmcpp_tools_transform)
+
+  add_executable(fastmcpp_tools_transform_ext tests/tools/test_tool_transform_extended.cpp)
+  target_link_libraries(fastmcpp_tools_transform_ext PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_tools_transform_ext COMMAND fastmcpp_tools_transform_ext)
+
+  add_executable(fastmcpp_tools_manager tests/tools/test_tool_manager.cpp)
+  target_link_libraries(fastmcpp_tools_manager PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_tools_manager COMMAND fastmcpp_tools_manager)
+
   add_executable(fastmcpp_integration tests/integration.cpp)
   target_link_libraries(fastmcpp_integration PRIVATE fastmcpp_core)
   add_test(NAME fastmcpp_integration COMMAND fastmcpp_integration)
@@ -222,6 +237,10 @@ if(FASTMCPP_BUILD_TESTS)
   target_link_libraries(fastmcpp_resources_advanced PRIVATE fastmcpp_core)
   add_test(NAME fastmcpp_resources_advanced COMMAND fastmcpp_resources_advanced)
 
+  add_executable(fastmcpp_resources_templates tests/resources/templates.cpp)
+  target_link_libraries(fastmcpp_resources_templates PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_resources_templates COMMAND fastmcpp_resources_templates)
+
   add_executable(fastmcpp_server_basic tests/server/basic.cpp)
   target_link_libraries(fastmcpp_server_basic PRIVATE fastmcpp_core)
   add_test(NAME fastmcpp_server_basic COMMAND fastmcpp_server_basic)
@@ -250,6 +269,21 @@ if(FASTMCPP_BUILD_TESTS)
   add_executable(fastmcpp_server_context_meta tests/server/context_meta.cpp)
   target_link_libraries(fastmcpp_server_context_meta PRIVATE fastmcpp_core)
   add_test(NAME fastmcpp_server_context_meta COMMAND fastmcpp_server_context_meta)
+  add_executable(fastmcpp_server_context_full tests/server/test_context_full.cpp)
+  target_link_libraries(fastmcpp_server_context_full PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_server_context_full COMMAND fastmcpp_server_context_full)
+
+  add_executable(fastmcpp_server_context_sse_integration tests/server/test_context_sse_integration.cpp)
+  target_link_libraries(fastmcpp_server_context_sse_integration PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_server_context_sse_integration COMMAND fastmcpp_server_context_sse_integration)
+
+  add_executable(fastmcpp_server_context_sampling tests/server/test_context_sampling.cpp)
+  target_link_libraries(fastmcpp_server_context_sampling PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_server_context_sampling COMMAND fastmcpp_server_context_sampling)
+
+  add_executable(fastmcpp_server_session tests/server/test_server_session.cpp)
+  target_link_libraries(fastmcpp_server_session PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_server_session COMMAND fastmcpp_server_session)
 
   add_executable(fastmcpp_server_security_limits tests/server/security_limits.cpp)
   target_link_libraries(fastmcpp_server_security_limits PRIVATE fastmcpp_core)
@@ -301,13 +335,28 @@ if(FASTMCPP_BUILD_TESTS)
   target_link_libraries(fastmcpp_server_middleware PRIVATE fastmcpp_core)
   add_test(NAME fastmcpp_server_middleware COMMAND fastmcpp_server_middleware)
 
+  add_executable(fastmcpp_server_middleware_pipeline tests/server/test_middleware_pipeline.cpp)
+  target_link_libraries(fastmcpp_server_middleware_pipeline PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_server_middleware_pipeline COMMAND fastmcpp_server_middleware_pipeline)
+
   add_executable(fastmcpp_stdio_client tests/transports/stdio_client.cpp)
   target_link_libraries(fastmcpp_stdio_client PRIVATE fastmcpp_core)
   add_test(NAME fastmcpp_stdio_client COMMAND fastmcpp_stdio_client)
 
   add_executable(fastmcpp_stdio_failure tests/transports/stdio_failure.cpp)
   target_link_libraries(fastmcpp_stdio_failure PRIVATE fastmcpp_core)
   add_test(NAME fastmcpp_stdio_failure COMMAND fastmcpp_stdio_failure)
+
+  # App mounting tests
+  add_executable(fastmcpp_app_mounting tests/app/mounting.cpp)
+  target_link_libraries(fastmcpp_app_mounting PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_app_mounting COMMAND fastmcpp_app_mounting)
+
+  # Proxy tests
+  add_executable(fastmcpp_proxy_basic tests/proxy/basic.cpp)
+  target_link_libraries(fastmcpp_proxy_basic PRIVATE fastmcpp_core)
+  add_test(NAME fastmcpp_proxy_basic COMMAND fastmcpp_proxy_basic)
+
   set_tests_properties(fastmcpp_stdio_client PROPERTIES
     LABELS "conformance"
     WORKING_DIRECTORY "$<TARGET_FILE_DIR:fastmcpp_stdio_client>"

include/fastmcpp/app.hpp

@@ -0,0 +1,192 @@
+#pragma once
+
+#include "fastmcpp/client/types.hpp"
+#include "fastmcpp/prompts/manager.hpp"
+#include "fastmcpp/proxy.hpp"
+#include "fastmcpp/resources/manager.hpp"
+#include "fastmcpp/server/server.hpp"
+#include "fastmcpp/tools/manager.hpp"
+
+#include <memory>
+#include <optional>
+#include <string>
+#include <vector>
+
+namespace fastmcpp
+{
+
+/// Mounted app reference with prefix (direct mode)
+struct MountedApp
+{
+    std::string prefix; // Prefix for tools/prompts (e.g., "weather")
+    class McpApp* app;  // Non-owning pointer to mounted app
+};
+
+/// Proxy-mounted app with prefix (proxy mode)
+struct ProxyMountedApp
+{
+    std::string prefix;              // Prefix for tools/prompts
+    std::unique_ptr<ProxyApp> proxy; // Owning pointer to proxy wrapper
+};
+
+/// MCP Application - bundles server metadata with managers
+///
+/// Similar to Python's FastMCP class. Provides:
+/// - Server metadata (name, version, icons, etc.)
+/// - Tool, Resource, and Prompt managers
+/// - App mounting support with prefixes
+///
+/// Usage:
+/// ```cpp
+/// McpApp main_app("MainApp", "1.0");
+/// McpApp weather_app("WeatherApp", "1.0");
+///
+/// // Register tools on sub-app
+/// weather_app.tools().register_tool(get_forecast_tool);
+///
+/// // Mount sub-app with prefix
+/// main_app.mount(weather_app, "weather");
+///
+/// // Tools accessible as "weather_get_forecast"
+/// ```
+class McpApp
+{
+  public:
+    /// Construct app with metadata
+    explicit McpApp(std::string name = "fastmcpp_app", std::string version = "1.0.0",
+                    std::optional<std::string> website_url = std::nullopt,
+                    std::optional<std::vector<Icon>> icons = std::nullopt);
+
+    // Metadata accessors
+    const std::string& name() const
+    {
+        return server_.name();
+    }
+    const std::string& version() const
+    {
+        return server_.version();
+    }
+    const std::optional<std::string>& website_url() const
+    {
+        return server_.website_url();
+    }
+    const std::optional<std::vector<Icon>>& icons() const
+    {
+        return server_.icons();
+    }
+
+    // Manager accessors
+    tools::ToolManager& tools()
+    {
+        return tools_;
+    }
+    const tools::ToolManager& tools() const
+    {
+        return tools_;
+    }
+
+    resources::ResourceManager& resources()
+    {
+        return resources_;
+    }
+    const resources::ResourceManager& resources() const
+    {
+        return resources_;
+    }
+
+    prompts::PromptManager& prompts()
+    {
+        return prompts_;
+    }
+    const prompts::PromptManager& prompts() const
+    {
+        return prompts_;
+    }
+
+    server::Server& server()
+    {
+        return server_;
+    }
+    const server::Server& server() const
+    {
+        return server_;
+    }
+
+    // =========================================================================
+    // App Mounting
+    // =========================================================================
+
+    /// Mount another app with an optional prefix
+    ///
+    /// Tools are prefixed with underscore: "prefix_toolname"
+    /// Resources are prefixed in URI: "prefix+resource://..." or "resource://prefix/..."
+    /// Prompts are prefixed with underscore: "prefix_promptname"
+    ///
+    /// @param app The app to mount (must outlive this app in direct mode)
+    /// @param prefix Optional prefix (empty string = no prefix)
+    /// @param as_proxy If true, mount in proxy mode (uses MCP handler for communication)
+    void mount(McpApp& app, const std::string& prefix = "", bool as_proxy = false);
+
+    /// Get list of directly mounted apps
+    const std::vector<MountedApp>& mounted() const
+    {
+        return mounted_;
+    }
+
+    /// Get list of proxy-mounted apps
+    const std::vector<ProxyMountedApp>& proxy_mounted() const
+    {
+        return proxy_mounted_;
+    }
+
+    // =========================================================================
+    // Aggregated Lists (includes mounted apps)
+    // =========================================================================
+
+    /// List all tools including from mounted apps
+    /// Tools from mounted apps have prefix: "prefix_toolname"
+    std::vector<std::pair<std::string, const tools::Tool*>> list_all_tools() const;
+
+    /// List all tools as ToolInfo (works for both direct and proxy mounts)
+    std::vector<client::ToolInfo> list_all_tools_info() const;
+
+    /// List all resources including from mounted apps
+    std::vector<resources::Resource> list_all_resources() const;
+
+    /// List all resource templates including from mounted apps
+    std::vector<resources::ResourceTemplate> list_all_templates() const;
+
+    /// List all prompts including from mounted apps
+    std::vector<std::pair<std::string, const prompts::Prompt*>> list_all_prompts() const;
+
+    // =========================================================================
+    // Routing (dispatches to correct app based on prefix)
+    // =========================================================================
+
+    /// Invoke a tool by name (handles prefixed routing)
+    Json invoke_tool(const std::string& name, const Json& args) const;
+
+    /// Read a resource by URI (handles prefixed routing)
+    resources::ResourceContent read_resource(const std::string& uri,
+                                             const Json& params = Json::object()) const;
+
+    /// Get prompt messages by name (handles prefixed routing)
+    std::vector<prompts::PromptMessage> get_prompt(const std::string& name, const Json& args) const;
+
+  private:
+    server::Server server_;
+    tools::ToolManager tools_;
+    resources::ResourceManager resources_;
+    prompts::PromptManager prompts_;
+    std::vector<MountedApp> mounted_;
+    std::vector<ProxyMountedApp> proxy_mounted_;
+
+    // Prefix utilities
+    static std::string add_prefix(const std::string& name, const std::string& prefix);
+    static std::pair<std::string, std::string> strip_prefix(const std::string& name);
+    static std::string add_resource_prefix(const std::string& uri, const std::string& prefix);
+    static std::string strip_resource_prefix(const std::string& uri, const std::string& prefix);
+    static bool has_resource_prefix(const std::string& uri, const std::string& prefix);
+};
+
+} // namespace fastmcpp

include/fastmcpp/client/client.hpp

@@ -56,6 +56,37 @@ class LoopbackTransport : public ITransport
     std::shared_ptr<fastmcpp::server::Server> server_;
 };
 
+/// In-process transport that uses an MCP handler function
+/// This is useful for proxy mode mounting where we want to communicate
+/// with a mounted app via its MCP handler
+class InProcessMcpTransport : public ITransport
+{
+  public:
+    using HandlerFn = std::function<fastmcpp::Json(const fastmcpp::Json&)>;
+
+    explicit InProcessMcpTransport(HandlerFn handler) : handler_(std::move(handler)) {}
+
+    fastmcpp::Json request(const std::string& route, const fastmcpp::Json& payload) override
+    {
+        // Build JSON-RPC request
+        static int request_id = 0;
+        fastmcpp::Json jsonrpc_request = {
+            {"jsonrpc", "2.0"}, {"id", ++request_id}, {"method", route}, {"params", payload}};
+
+        // Call handler
+        fastmcpp::Json response = handler_(jsonrpc_request);
+
+        // Extract result or error
+        if (response.contains("error"))
+            throw fastmcpp::Error(response["error"].value("message", "Unknown error"));
+
+        return response.value("result", fastmcpp::Json::object());
+    }
+
+  private:
+    HandlerFn handler_;
+};
+
 // ============================================================================
 // Call Options
 // ============================================================================