Grammarly MCP Server

#!/usr/bin/env node import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js"; import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js"; import { config, log } from "./config"; import { type GrammarlyOptimizeInput, type GrammarlyOptimizeResult, type ProgressCallback, runGrammarlyOptimization, ToolInputSchema, ToolOutputSchema, } from "./grammarlyOptimizer"; /** * Format optimization result as human-readable markdown. */ export function formatAsMarkdown(result: GrammarlyOptimizeResult): string { const statusEmoji = result.thresholds_met ? "✅" : "⚠️"; const aiScore = result.ai_detection_percent !== null ? `${result.ai_detection_percent}%` : "N/A"; const plagiarismScore = result.plagiarism_percent !== null ? `${result.plagiarism_percent}%` : "N/A"; const lines: string[] = [ `# Grammarly Optimization Result ${statusEmoji}`, "", "## Summary", "", `| Metric | Value |`, `|--------|-------|`, `| AI Detection | ${aiScore} |`, `| Plagiarism | ${plagiarismScore} |`, `| Thresholds Met | ${result.thresholds_met ? "Yes" : "No"} |`, `| Iterations Used | ${result.iterations_used} |`, ]; if (result.live_url) { lines.push(`| Live Preview | [Browser Session](${result.live_url}) |`); } lines.push("", "## Notes", "", result.notes); if (result.history.length > 0) { lines.push("", "## Iteration History", ""); lines.push("| Iteration | AI % | Plagiarism % | Note |"); lines.push("|-----------|------|--------------|------|"); for (const entry of result.history) { const ai = entry.ai_detection_percent !== null ? `${entry.ai_detection_percent}%` : "N/A"; const plag = entry.plagiarism_percent !== null ? `${entry.plagiarism_percent}%` : "N/A"; // Truncate long notes for table readability const note = entry.note.length > 60 ? `${entry.note.slice(0, 57)}...` : entry.note; lines.push(`| ${entry.iteration} | ${ai} | ${plag} | ${note} |`); } } lines.push( "", "---", "", "## Final Text", "", "```", result.final_text, "```", ); return lines.join("\n"); } /** * Create and configure the MCP server. * * This server implements MCP specification 2025-11-25 with: * - registerTool() API (replaces deprecated tool()) * - Tool annotations for client hints * - Output schema for structured responses * - Tasks support for async operations (experimental) * - Progress notifications during long operations */ async function main(): Promise<void> { const server = new McpServer( { name: "grammarly-mcp", version: "0.1.0", }, { capabilities: { logging: {}, }, }, ); server.registerTool( "grammarly_optimize_text", { title: "Grammarly Text Optimizer", description: "Get AI detection and plagiarism scores from Grammarly, optionally rewriting text with the configured LLM to reduce scores. " + "Modes: 'score_only' (scores only), 'analyze' (scores + recommendations), 'optimize' (iterative rewriting to meet thresholds).", inputSchema: ToolInputSchema, outputSchema: ToolOutputSchema, annotations: { readOnlyHint: false, // Tool can rewrite text destructiveHint: false, // Non-destructive (original preserved in input) idempotentHint: false, // Each run may produce different results openWorldHint: true, // Interacts with Grammarly and external LLM APIs }, }, async (args, extra) => { const parsed = ToolInputSchema.parse(args) as GrammarlyOptimizeInput; log("info", "Received grammarly_optimize_text tool call", { mode: parsed.mode, max_ai_percent: parsed.max_ai_percent, max_plagiarism_percent: parsed.max_plagiarism_percent, max_iterations: parsed.max_iterations, }); // Create progress callback for MCP progress notifications. // Prefer a public accessor if available (MCP SDK >=1.25.x expected to expose a getter; // see README), and only fall back to the private `_meta` escape hatch when nothing // else exists. // Allow either the public getter (preferred) or fall back to legacy fields. type ProgressTokenCarrier = { getProgressToken?: () => unknown; progressToken?: unknown; meta?: { progressToken?: unknown }; /** legacy/private hook */ // biome-ignore lint/style/useNamingConvention: external SDK uses _meta for request metadata _meta?: { progressToken?: unknown }; }; const progressTokenCarrier = extra as unknown as ProgressTokenCarrier; const progressTokenCandidate = typeof progressTokenCarrier.getProgressToken === "function" ? progressTokenCarrier.getProgressToken() : (progressTokenCarrier.progressToken ?? progressTokenCarrier.meta?.progressToken ?? // Legacy/private path: keep guarded to avoid hard-coupling to internals. progressTokenCarrier._meta?.progressToken); const progressToken = typeof progressTokenCandidate === "string" || typeof progressTokenCandidate === "number" ? progressTokenCandidate : undefined; const onProgress: ProgressCallback = async (message, progress) => { if (extra.sendNotification && progressToken) { try { await extra.sendNotification({ method: "notifications/progress", params: { progressToken, progress: progress ?? 0, total: 100, message, }, }); } catch (err) { log("debug", "Failed to send progress notification", { error: err instanceof Error ? err.message : err, }); } } log("debug", `Progress: ${message}`, { progress }); }; const result = await runGrammarlyOptimization(config, parsed, onProgress); const validatedOutput = ToolOutputSchema.parse(result); // Format output based on response_format preference // Use result (GrammarlyOptimizeResult) for formatting, validatedOutput for structuredContent const textSummary = parsed.response_format === "markdown" ? formatAsMarkdown(result) : JSON.stringify(validatedOutput, null, 2); return { content: [ { type: "text", text: textSummary, }, ], structuredContent: validatedOutput, }; }, ); const transport = new StdioServerTransport(); log("info", "Starting Grammarly Browser Use MCP server over stdio"); const timeoutMs = config.connectTimeoutMs; const connectPromise = server.connect(transport); let timeoutHandle: NodeJS.Timeout | undefined; const timeoutPromise = new Promise<never>((_, reject) => { timeoutHandle = setTimeout(() => { reject(new Error(`Server connect timed out after ${timeoutMs}ms`)); }, timeoutMs); }); try { await Promise.race([connectPromise, timeoutPromise]); } catch (error: unknown) { if (timeoutHandle) { clearTimeout(timeoutHandle); } log("error", "Failed to start MCP server", { message: error instanceof Error ? error.message : String(error), }); // Attempt to clean up the transport if it exposes a close method. const maybeClose = (transport as { close?: () => unknown }).close; if (typeof maybeClose === "function") { try { await maybeClose(); } catch { // Ignore cleanup errors } } process.exit(1); } finally { if (timeoutHandle) { clearTimeout(timeoutHandle); } } } // Top-level await is supported in Node 18+ ESM. void main().catch((error: unknown) => { if (error instanceof Error) { console.error("Fatal error:", error.message); console.error(error.stack ?? "(no stack trace)"); } else { console.error("Fatal error (non-Error):", error); } process.exit(1); });