fix: make Cursor hooks transactional

src/plugins/guard-template.ts

@@ -0,0 +1,190 @@
+import { PROTECTED_RUNTIME_READER } from './runtime-reader-template.js';
+
+export interface GuardScriptOptions {
+  readonly failClosed?: boolean;
+  readonly successOutput?: string;
+}
+
+export function generateGuardScript(
+  agentName: string,
+  agentId: string,
+  options: GuardScriptOptions = {},
+): string {
+  const failClosed = options.failClosed ?? false;
+  const successOutput = options.successOutput ?? '';
+  return `#!/usr/bin/env node
+'use strict';
+
+// Elydora agent guard for ${agentName}. Generated by @elydora/sdk.
+const fs = require('node:fs');
+const path = require('node:path');
+const os = require('node:os');
+
+const AGENT_NAME = ${JSON.stringify(agentName)};
+const AGENT_ID = ${JSON.stringify(agentId)};
+const SUCCESS_OUTPUT = ${JSON.stringify(successOutput)};
+const FAIL_CLOSED = ${JSON.stringify(failClosed)};
+const ELYDORA_DIR = path.join(os.homedir(), '.elydora');
+const CONFIG_PATH = path.join(ELYDORA_DIR, AGENT_ID, 'config.json');
+const STATUS_CACHE_PATH = path.join(ELYDORA_DIR, AGENT_ID, 'status-cache.json');
+const CACHE_TTL_MS = 60000;
+
+${PROTECTED_RUNTIME_READER}
+
+function validateStatus(value, source) {
+  if (!['active', 'frozen', 'revoked'].includes(value)) {
+    throw new Error(source + ' contains an invalid agent status');
+  }
+  return value;
+}
+
+function blockAgent(status) {
+  const state = status === 'frozen' ? 'frozen' : 'revoked';
+  const message = 'Agent "' + AGENT_NAME + '" is ' + state + ' in Elydora.';
+  if (SUCCESS_OUTPUT) {
+    process.stdout.write(JSON.stringify({
+      permission: 'deny',
+      userMessage: message,
+      agentMessage: message + ' Tool execution is blocked.',
+    }) + '\\n');
+  }
+  process.stderr.write('[Elydora guard] ' + message + ' Tool execution blocked.\\n');
+  process.exitCode = 2;
+}
+
+function readStatusCache() {
+  let raw;
+  try {
+    raw = fs.readFileSync(STATUS_CACHE_PATH, 'utf-8');
+  } catch (error) {
+    if (error.code === 'ENOENT') return undefined;
+    throw new Error('Failed to read status cache: ' + error.message);
+  }
+  let cache;
+  try {
+    cache = JSON.parse(raw);
+  } catch (error) {
+    throw new Error('Status cache is invalid JSON: ' + error.message);
+  }
+  if (!cache || typeof cache !== 'object' || !Number.isFinite(cache.cached_at)) {
+    throw new Error('Status cache has an invalid shape');
+  }
+  const age = Date.now() - cache.cached_at;
+  if (age < 0) throw new Error('Status cache timestamp is in the future');
+  return { status: validateStatus(cache.status, 'Status cache'), age };
+}
+
+function writeStatusCache(status) {
+  const temporaryPath = STATUS_CACHE_PATH + '.' + process.pid + '.tmp';
+  try {
+    fs.writeFileSync(temporaryPath, JSON.stringify({
+      status,
+      cached_at: Date.now(),
+    }), { encoding: 'utf-8', mode: 0o600, flag: 'wx' });
+    try {
+      fs.renameSync(temporaryPath, STATUS_CACHE_PATH);
+    } catch (error) {
+      if (process.platform !== 'win32' || !['EEXIST', 'EPERM'].includes(error.code)) throw error;
+      try { fs.unlinkSync(STATUS_CACHE_PATH); } catch (unlinkError) {
+        if (unlinkError.code !== 'ENOENT') throw unlinkError;
+      }
+      fs.renameSync(temporaryPath, STATUS_CACHE_PATH);
+    }
+  } finally {
+    try { fs.unlinkSync(temporaryPath); } catch (error) {
+      if (error.code !== 'ENOENT') throw error;
+    }
+  }
+}
+
+async function readInput() {
+  const chunks = [];
+  for await (const chunk of process.stdin) chunks.push(chunk);
+  const raw = Buffer.concat(chunks).toString('utf-8').trim();
+  if (!raw) {
+    if (FAIL_CLOSED) throw new Error('Hook input is empty');
+    return;
+  }
+  try {
+    JSON.parse(raw);
+  } catch (error) {
+    if (FAIL_CLOSED) throw new Error('Hook input is invalid JSON: ' + error.message);
+  }
+}
+
+function readConfig() {
+  const raw = readProtectedFile(
+    CONFIG_PATH,
+    'Agent config',
+    MAX_PROTECTED_CONFIG_BYTES,
+  ).toString('utf-8');
+  let config;
+  try {
+    config = JSON.parse(raw);
+  } catch (error) {
+    throw new Error('Agent config is invalid JSON: ' + error.message);
+  }
+  if (!config || typeof config !== 'object') throw new Error('Agent config must be an object');
+  if (config.agent_id !== AGENT_ID
+      || (config.agent_name !== undefined && config.agent_name !== AGENT_NAME)) {
+    throw new Error('Agent config identity does not match the generated guard');
+  }
+  return config;
+}
+
+async function main() {
+  await readInput();
+  let config;
+  try {
+    config = readConfig();
+  } catch (error) {
+    if (FAIL_CLOSED) throw new Error('Failed to read agent config: ' + error.message);
+    process.stderr.write('[Elydora guard] Failed to read agent config: ' + error.message + '\\n');
+    return;
+  }
+
+  try {
+    const cache = readStatusCache();
+    if (cache && cache.age < CACHE_TTL_MS) {
+      if (cache.status !== 'active') blockAgent(cache.status);
+      return;
+    }
+  } catch (error) {
+    if (FAIL_CLOSED) throw error;
+    process.stderr.write('[Elydora guard] ' + error.message + '\\n');
+  }
+
+  const baseUrl = String(config.base_url || 'https://api.elydora.com').replace(/\\\/+$/, '');
+  const token = config.token || '';
+  const controller = new AbortController();
+  const timeout = setTimeout(() => controller.abort(), 3000);
+  try {
+    const headers = { Accept: 'application/json' };
+    if (token) headers.Authorization = 'Bearer ' + token;
+    const response = await fetch(baseUrl + '/v1/agents/' + encodeURIComponent(AGENT_ID), {
+      headers,
+      signal: controller.signal,
+    });
+    if (!response.ok) throw new Error('Agent status API returned HTTP ' + response.status);
+    const data = await response.json();
+    const status = validateStatus(data && data.agent && data.agent.status, 'Agent status API');
+    writeStatusCache(status);
+    if (status !== 'active') blockAgent(status);
+  } catch (error) {
+    if (FAIL_CLOSED) throw new Error('Failed to resolve agent status: ' + error.message);
+    process.stderr.write('[Elydora guard] Failed to resolve agent status: ' + error.message + '\\n');
+  } finally {
+    clearTimeout(timeout);
+  }
+}
+
+main().then(() => {
+  if ((!process.exitCode || process.exitCode === 0) && SUCCESS_OUTPUT) {
+    process.stdout.write(SUCCESS_OUTPUT);
+  }
+}).catch((error) => {
+  process.stderr.write('[Elydora guard] ' + (error.stack || error.message || String(error)) + '\\n');
+  process.exitCode = 1;
+});
+`;
+}