NCP - Natural Context Provider

/** * Context-Aware Credential Prompter * * Collects sensitive credentials using appropriate method based on context: * Priority: * 1. MCP Elicitation (if available) - Best for AI clients * 2. Native OS dialogs - Fallback for MCP server mode * 3. Terminal readline - For CLI usage */ import { createInterface } from 'readline'; import { showNativeDialog } from './native-dialog.js'; import { collectCredential as collectViaElicitation, ElicitationServer } from './elicitation-helper.js'; import { logger } from './logger.js'; export interface CredentialPromptOptions { name: string; // Human-readable name (e.g., "Bearer Token", "API Key") description?: string; // Additional context hidden?: boolean; // Hide input (default: true for credentials) example?: string; // Example value to show user elicitationServer?: ElicitationServer; // Optional elicitation server for MCP protocol } /** * Detect if we're running in terminal mode vs MCP server mode */ function isTerminalMode(): boolean { // Check if stdin is a TTY (interactive terminal) if (!process.stdin.isTTY) { return false; } // Check if explicitly running as MCP server if (process.env.MCP_SERVER_MODE === 'true') { return false; } return true; } /** * Check if elicitation is available and supported */ function hasElicitationSupport(server?: ElicitationServer): boolean { if (!server) { return false; } // Check if the server has the elicitInput method if (typeof server.elicitInput !== 'function') { return false; } // We're in MCP server mode if elicitation server is provided return true; } /** * Prompt for credential in terminal using readline * Uses hidden input for secure credential entry */ async function promptInTerminal(options: CredentialPromptOptions): Promise<string | null> { return new Promise((resolve) => { const prompt = options.description ? `🔐 ${options.name}\n ${options.description}\n Enter value${options.hidden !== false ? ' (hidden)' : ''}: ` : `🔐 Enter ${options.name}${options.hidden !== false ? ' (hidden)' : ''}: `; if (options.hidden !== false) { // Use raw mode for hidden input const stdin = process.stdin; let input = ''; // Show prompt process.stdout.write(prompt); // Set raw mode to capture keystrokes without echo if (stdin.isTTY) { stdin.setRawMode(true); } stdin.resume(); stdin.setEncoding('utf8'); const onData = (char: string) => { switch (char) { case '\n': case '\r': case '\u0004': // Ctrl-D (EOF) // Cleanup stdin.pause(); if (stdin.isTTY) { stdin.setRawMode(false); } stdin.removeListener('data', onData); // New line after hidden input process.stdout.write('\n'); // Resolve with input or null if empty if (!input || input.trim().length === 0) { resolve(null); } else { resolve(input.trim()); } break; case '\u0003': // Ctrl-C // Cleanup and cancel stdin.pause(); if (stdin.isTTY) { stdin.setRawMode(false); } stdin.removeListener('data', onData); process.stdout.write('\n'); resolve(null); break; case '\u007f': // Backspace case '\b': // Backspace if (input.length > 0) { input = input.slice(0, -1); // No visual feedback for hidden input } break; default: // Add character to input (only printable characters) if (char.charCodeAt(0) >= 32) { input += char; } break; } }; stdin.on('data', onData); } else { // Regular visible input using readline const rl = createInterface({ input: process.stdin, output: process.stdout }); rl.question(prompt, (answer) => { rl.close(); if (!answer || answer.trim().length === 0) { resolve(null); } else { resolve(answer.trim()); } }); } }); } /** * Prompt for credential using native OS dialog * More appropriate when used as MCP server by AI clients */ async function promptWithDialog(options: CredentialPromptOptions): Promise<string | null> { const exampleText = options.example ? `\n\nExample: ${options.example}` : ''; const descriptionText = options.description ? `\n${options.description}` : ''; const message = `Enter your ${options.name}${descriptionText}${exampleText}\n\nThe value will be stored securely in your NCP profile configuration.`; try { const result = await showNativeDialog({ title: `${options.name} Required`, message, buttons: ['OK', 'Cancel'], icon: 'question', timeoutSeconds: 120 // 2 minutes for user to fetch credential }); if (result.cancelled || result.timedOut) { logger.info(`User ${result.timedOut ? 'timed out' : 'cancelled'} credential prompt for ${options.name}`); return null; } // For dialogs, we need a secondary input method // Fall back to terminal input if dialog doesn't support text input logger.info('Dialog confirmed, falling back to terminal input for actual credential'); return await promptInTerminal(options); } catch (error: any) { logger.error(`Dialog failed for ${options.name}: ${error.message}`); // Fallback to terminal return await promptInTerminal(options); } } /** * Prompt user for a credential using context-appropriate method * * Priority chain: * 1. MCP Elicitation (if elicitationServer provided) - MCP protocol standard * 2. Native OS dialog (if not terminal mode) - Fallback for MCP server * 3. Terminal readline (if terminal mode) - CLI usage * * @param options Credential prompt configuration * @returns The credential value, or null if user cancelled */ export async function promptForCredential(options: CredentialPromptOptions): Promise<string | null> { try { // Priority 1: Use MCP elicitation if available (MCP protocol standard) if (hasElicitationSupport(options.elicitationServer)) { logger.debug(`Using MCP elicitation for ${options.name}`); try { const credential = await collectViaElicitation( options.elicitationServer!, options.name, options.name.toUpperCase().replace(/\s+/g, '_'), options.example ); if (credential) { return credential; } // User cancelled or elicitation failed, try fallback logger.warn(`Elicitation failed or cancelled for ${options.name}, trying fallback`); } catch (error: any) { logger.warn(`Elicitation error for ${options.name}: ${error.message}, trying fallback`); } } // Priority 2/3: Fall back to dialog or terminal based on context if (isTerminalMode()) { logger.debug(`Using terminal mode for ${options.name}`); return await promptInTerminal(options); } else { logger.debug(`Using dialog mode for ${options.name}`); return await promptWithDialog(options); } } catch (error: any) { logger.error(`Failed to prompt for ${options.name}: ${error.message}`); return null; } } /** * Prompt for multiple credentials sequentially * Stops if user cancels any prompt * * @param credentials Array of credential prompts * @returns Map of credential names to values, or null if any cancelled */ export async function promptForCredentials( credentials: CredentialPromptOptions[] ): Promise<Record<string, string> | null> { const results: Record<string, string> = {}; for (const cred of credentials) { const value = await promptForCredential(cred); if (value === null) { logger.info(`Credential collection cancelled at ${cred.name}`); return null; } results[cred.name] = value; } return results; }