Files
whetstone_DSL/editor/src/MCPBridge.h
Bill 80b5a199cb Sprint 7 Phase 7b: MCP server with tools, resources, and prompts (Steps 207-213)
- Step 207: MCPServer.h — MCP protocol core with JSON-RPC 2.0 stdio transport,
  initialize/initialized handshake, capabilities (tools, resources, prompts)
- Step 208: 5 AST tools — whetstone_get_ast, whetstone_mutate, whetstone_batch_mutate,
  whetstone_get_scope, whetstone_get_call_hierarchy
- Step 209: 5 annotation/generation tools — whetstone_suggest_annotations,
  whetstone_apply_annotation, whetstone_generate_code, whetstone_run_pipeline,
  whetstone_project_language
- Step 210: 5 MCP resources — ast, diagnostics, libraries, annotations, settings
- Step 211: 4 MCP prompts — annotate_module, cross_language_projection,
  security_audit, refactor_memory
- Step 212: MCPBridge.h — stdio transport with Content-Length framing,
  bridges MCP to Whetstone JSON-RPC
- Step 213: MCP server tests — 90/90 assertions pass

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-02-10 07:45:11 -07:00

78 lines
2.5 KiB
C++

#pragma once
// Step 212: MCP Bridge
//
// Translates between the MCP stdio transport and Whetstone's internal
// JSON-RPC handler. In embedded mode, directly calls processAgentRequest.
// In standalone mode, would connect via WebSocket to a running editor.
#include <string>
#include <iostream>
#include <nlohmann/json.hpp>
#include "MCPServer.h"
using json = nlohmann::json;
class MCPBridge {
public:
// Set up the bridge with a direct RPC handler (embedded mode)
void setRequestHandler(MCPServer::RpcCallback handler) {
server_.setRpcCallback(std::move(handler));
}
// Set up the resource reader
void setResourceReader(MCPServer::ResourceReader reader) {
server_.setResourceReader(std::move(reader));
}
MCPServer& server() { return server_; }
// Process a single JSON-RPC message string, return response string
std::string processMessage(const std::string& message) {
try {
json request = json::parse(message);
json response = server_.handleRequest(request);
if (response.is_null()) return ""; // notifications have no response
return response.dump();
} catch (const json::parse_error& e) {
json error = {
{"jsonrpc", "2.0"},
{"id", nullptr},
{"error", {{"code", -32700}, {"message", "Parse error"}}}
};
return error.dump();
}
}
// Run the stdio transport loop (for standalone mcp_main.cpp)
// Reads JSON-RPC messages from stdin, writes responses to stdout.
// MCP uses Content-Length framing over stdio.
void runStdio() {
std::string line;
while (std::getline(std::cin, line)) {
// MCP stdio transport: Content-Length header followed by JSON body
if (line.find("Content-Length:") == 0) {
int length = 0;
try {
length = std::stoi(line.substr(15));
} catch (...) {
continue;
}
// Skip empty line after headers
std::getline(std::cin, line);
// Read body
std::string body(length, '\0');
std::cin.read(&body[0], length);
std::string response = processMessage(body);
if (!response.empty()) {
std::cout << "Content-Length: " << response.size() << "\r\n\r\n" << response;
std::cout.flush();
}
}
}
}
private:
MCPServer server_;
};