diff --git a/package.json b/package.json
index 04ef933..e0ea85a 100644
--- a/package.json
+++ b/package.json
@@ -10,6 +10,7 @@
   "scripts": {
     "build": "tsc",
     "dev": "tsx src/index.ts",
+    "bird": "pnpm run build && node dist/index.js",
     "test": "vitest run",
     "test:watch": "vitest",
     "lint": "biome check .",
@@ -20,7 +21,9 @@
   },
   "dependencies": {
     "commander": "^12.1.0",
-    "devalue": "^5.1.0"
+    "devalue": "^5.1.0",
+    "json5": "^2.2.3",
+    "kleur": "^4.1.5"
   },
   "devDependencies": {
     "@biomejs/biome": "^1.9.4",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 8f20be6..e166e9f 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -14,6 +14,12 @@ importers:
       devalue:
         specifier: ^5.1.0
         version: 5.5.0
+      json5:
+        specifier: ^2.2.3
+        version: 2.2.3
+      kleur:
+        specifier: ^4.1.5
+        version: 4.1.5
     devDependencies:
       '@biomejs/biome':
         specifier: ^1.9.4
@@ -592,6 +598,15 @@ packages:
   get-tsconfig@4.13.0:
     resolution: {integrity: sha512-1VKTZJCwBrvbd+Wn3AOgQP/2Av+TfTCOlE4AcRJE72W1ksZXbAx8PPBR9RzgTeSPzlPMHrbANMH3LbltH73wxQ==}
 
+  json5@2.2.3:
+    resolution: {integrity: sha512-XmOWe7eyHYH14cLdVPoyg+GOH3rYX++KpzrylJwSW98t3Nk+U8XOl8FWKOgwtzdb8lXGf6zYwDUzeHMWfxasyg==}
+    engines: {node: '>=6'}
+    hasBin: true
+
+  kleur@4.1.5:
+    resolution: {integrity: sha512-o+NO+8WrRiQEE4/7nwRJhN1HWpVmJm511pBHUxPLtp0BUISzlBplORYSmTclCnJvQq2tKu/sgl3xVpkc7ZWuQQ==}
+    engines: {node: '>=6'}
+
   loupe@3.2.1:
     resolution: {integrity: sha512-CdzqowRJCeLU72bHvWqwRBBlLcMEtIvGrlvef74kMnV2AolS9Y8xUv1I0U/MNAWMhBlKIoyuEgoJ0t/bbwHbLQ==}
 
@@ -1130,6 +1145,10 @@ snapshots:
     dependencies:
       resolve-pkg-maps: 1.0.0
 
+  json5@2.2.3: {}
+
+  kleur@4.1.5: {}
+
   loupe@3.2.1: {}
 
   magic-string@0.30.21:
diff --git a/src/index.ts b/src/index.ts
index 3ceef0f..c4b4f47 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -10,6 +10,11 @@
  */
 
 import { Command } from 'commander';
+import JSON5 from 'json5';
+import kleur from 'kleur';
+import { homedir } from 'node:os';
+import { existsSync, readFileSync } from 'node:fs';
+import { join } from 'node:path';
 import { resolveCredentials } from './lib/cookies.js';
 import { extractTweetId } from './lib/extract-tweet-id.js';
 import { TwitterClient, type TweetData } from './lib/twitter-client.js';
@@ -17,19 +22,87 @@ import { SweetisticsClient } from './lib/sweetistics-client.js';
 
 const program = new Command();
 
+const isTty = process.stdout.isTTY;
+const wrap = (styler: (text: string) => string) => (text: string) => (isTty ? styler(text) : text);
+
+const colors = {
+  banner: wrap((t) => kleur.bold().blue(t)),
+  subtitle: wrap((t) => kleur.dim(t)),
+  section: wrap((t) => kleur.bold().white(t)),
+  bullet: wrap((t) => kleur.blue(t)),
+  command: wrap((t) => kleur.bold().cyan(t)),
+  option: wrap((t) => kleur.cyan(t)),
+  argument: wrap((t) => kleur.magenta(t)),
+  description: wrap((t) => kleur.white(t)),
+  muted: wrap((t) => kleur.gray(t)),
+  accent: wrap((t) => kleur.green(t)),
+};
+
+type BirdConfig = {
+  engine?: EngineMode;
+  chromeProfile?: string;
+  firefoxProfile?: string;
+  sweetisticsApiKey?: string;
+  sweetisticsBaseUrl?: string;
+};
+
+function readConfigFile(path: string): Partial<BirdConfig> {
+  if (!existsSync(path)) return {};
+  try {
+    const raw = readFileSync(path, 'utf8');
+    const parsed = JSON5.parse(raw) as Partial<BirdConfig>;
+    return parsed ?? {};
+  } catch (error) {
+    console.error(colors.muted(`⚠️  Failed to parse config at ${path}: ${error instanceof Error ? error.message : String(error)}`));
+    return {};
+  }
+}
+
+function loadConfig(): BirdConfig {
+  const globalPath = join(homedir(), '.config', 'bird', 'config.json5');
+  const localPath = join(process.cwd(), '.birdrc.json5');
+
+  return {
+    ...readConfigFile(globalPath),
+    ...readConfigFile(localPath),
+  };
+}
+
+const config = loadConfig();
+
+program.addHelpText('beforeAll', () => `${colors.banner('bird CLI')} ${colors.subtitle('— tweet from your terminal')}`);
+
 program.name('bird').description('Post tweets and replies via Twitter/X GraphQL API').version('0.1.0');
 
+const formatExample = (command: string, description: string) =>
+  `${colors.command(`  ${command}`)}\n${colors.muted(`    ${description}`)}`;
+
+program.addHelpText(
+  'afterAll',
+  () => `\n${colors.section('Examples')}\n${[
+    formatExample('bird whoami', 'Show the logged-in account via GraphQL cookies'),
+    formatExample('bird --firefox-profile default-release whoami', 'Use Firefox profile cookies'),
+    formatExample('bird tweet "hello from bird"', 'Send a tweet'),
+    formatExample('bird replies https://x.com/user/status/1234567890123456789', 'Check replies to a tweet'),
+  ].join('\n\n')}`,
+);
+
 // Global options for authentication
 program
   .option('--auth-token <token>', 'Twitter auth_token cookie')
   .option('--ct0 <token>', 'Twitter ct0 cookie')
-  .option('--chrome-profile <name>', 'Chrome profile name for cookie extraction')
+  .option('--chrome-profile <name>', 'Chrome profile name for cookie extraction', config.chromeProfile)
+  .option('--firefox-profile <name>', 'Firefox profile name for cookie extraction', config.firefoxProfile)
   .option('--sweetistics-api-key <key>', 'Sweetistics API key (or set SWEETISTICS_API_KEY)')
-  .option('--sweetistics-base-url <url>', 'Sweetistics base URL', process.env.SWEETISTICS_BASE_URL || 'https://sweetistics.com')
+  .option(
+    '--sweetistics-base-url <url>',
+    'Sweetistics base URL',
+    config.sweetisticsBaseUrl || process.env.SWEETISTICS_BASE_URL || 'https://sweetistics.com',
+  )
   .option(
     '--engine <engine>',
     'Engine: graphql | sweetistics | auto',
-    process.env.BIRD_ENGINE || 'auto',
+    process.env.BIRD_ENGINE || config.engine || 'auto',
   );
 
 type EngineMode = 'graphql' | 'sweetistics' | 'auto';
@@ -92,7 +165,10 @@ program
   .argument('<text>', 'Tweet text')
   .action(async (text: string) => {
     const opts = program.opts();
-    const sweetistics = resolveSweetisticsConfig(opts);
+    const sweetistics = resolveSweetisticsConfig({
+      sweetisticsApiKey: opts.sweetisticsApiKey || config.sweetisticsApiKey,
+      sweetisticsBaseUrl: opts.sweetisticsBaseUrl || config.sweetisticsBaseUrl,
+    });
     const engine = resolveEngineMode(opts.engine);
     const useSweetistics = shouldUseSweetistics(engine, Boolean(sweetistics.apiKey));
 
@@ -125,7 +201,8 @@ program
     const { cookies, warnings } = await resolveCredentials({
       authToken: opts.authToken,
       ct0: opts.ct0,
-      chromeProfile: opts.chromeProfile,
+      chromeProfile: opts.chromeProfile || config.chromeProfile,
+      firefoxProfile: opts.firefoxProfile || config.firefoxProfile,
     });
 
     for (const warning of warnings) {
@@ -161,7 +238,10 @@ program
   .argument('<text>', 'Reply text')
   .action(async (tweetIdOrUrl: string, text: string) => {
     const opts = program.opts();
-    const sweetistics = resolveSweetisticsConfig(opts);
+    const sweetistics = resolveSweetisticsConfig({
+      sweetisticsApiKey: opts.sweetisticsApiKey || config.sweetisticsApiKey,
+      sweetisticsBaseUrl: opts.sweetisticsBaseUrl || config.sweetisticsBaseUrl,
+    });
     const engine = resolveEngineMode(opts.engine);
     const useSweetistics = shouldUseSweetistics(engine, Boolean(sweetistics.apiKey));
     const tweetId = extractTweetId(tweetIdOrUrl);
@@ -195,7 +275,8 @@ program
     const { cookies, warnings } = await resolveCredentials({
       authToken: opts.authToken,
       ct0: opts.ct0,
-      chromeProfile: opts.chromeProfile,
+      chromeProfile: opts.chromeProfile || config.chromeProfile,
+      firefoxProfile: opts.firefoxProfile || config.firefoxProfile,
     });
 
     for (const warning of warnings) {
@@ -233,7 +314,10 @@ program
   .option('--json', 'Output as JSON')
   .action(async (tweetIdOrUrl: string, cmdOpts: { json?: boolean }) => {
     const opts = program.opts();
-    const sweetistics = resolveSweetisticsConfig(opts);
+    const sweetistics = resolveSweetisticsConfig({
+      sweetisticsApiKey: opts.sweetisticsApiKey || config.sweetisticsApiKey,
+      sweetisticsBaseUrl: opts.sweetisticsBaseUrl || config.sweetisticsBaseUrl,
+    });
     const engine = resolveEngineMode(opts.engine);
     const useSweetistics = shouldUseSweetistics(engine, Boolean(sweetistics.apiKey));
 
@@ -267,7 +351,8 @@ program
     const { cookies, warnings } = await resolveCredentials({
       authToken: opts.authToken,
       ct0: opts.ct0,
-      chromeProfile: opts.chromeProfile,
+      chromeProfile: opts.chromeProfile || config.chromeProfile,
+      firefoxProfile: opts.firefoxProfile || config.firefoxProfile,
     });
 
     for (const warning of warnings) {
@@ -309,7 +394,10 @@ program
   .option('--json', 'Output as JSON')
   .action(async (tweetIdOrUrl: string, cmdOpts: { json?: boolean }) => {
     const opts = program.opts();
-    const sweetistics = resolveSweetisticsConfig(opts);
+    const sweetistics = resolveSweetisticsConfig({
+      sweetisticsApiKey: opts.sweetisticsApiKey || config.sweetisticsApiKey,
+      sweetisticsBaseUrl: opts.sweetisticsBaseUrl || config.sweetisticsBaseUrl,
+    });
     const engine = resolveEngineMode(opts.engine);
     const useSweetistics = shouldUseSweetistics(engine, Boolean(sweetistics.apiKey));
     const tweetId = extractTweetId(tweetIdOrUrl);
@@ -331,7 +419,8 @@ program
     const { cookies, warnings } = await resolveCredentials({
       authToken: opts.authToken,
       ct0: opts.ct0,
-      chromeProfile: opts.chromeProfile,
+      chromeProfile: opts.chromeProfile || config.chromeProfile,
+      firefoxProfile: opts.firefoxProfile || config.firefoxProfile,
     });
 
     for (const warning of warnings) {
@@ -362,7 +451,10 @@ program
   .option('--json', 'Output as JSON')
   .action(async (tweetIdOrUrl: string, cmdOpts: { json?: boolean }) => {
     const opts = program.opts();
-    const sweetistics = resolveSweetisticsConfig(opts);
+    const sweetistics = resolveSweetisticsConfig({
+      sweetisticsApiKey: opts.sweetisticsApiKey || config.sweetisticsApiKey,
+      sweetisticsBaseUrl: opts.sweetisticsBaseUrl || config.sweetisticsBaseUrl,
+    });
     const engine = resolveEngineMode(opts.engine);
     const useSweetistics = shouldUseSweetistics(engine, Boolean(sweetistics.apiKey));
     const tweetId = extractTweetId(tweetIdOrUrl);
@@ -384,7 +476,8 @@ program
     const { cookies, warnings } = await resolveCredentials({
       authToken: opts.authToken,
       ct0: opts.ct0,
-      chromeProfile: opts.chromeProfile,
+      chromeProfile: opts.chromeProfile || config.chromeProfile,
+      firefoxProfile: opts.firefoxProfile || config.firefoxProfile,
     });
 
     for (const warning of warnings) {
@@ -417,7 +510,10 @@ program
   .action(async (query: string, cmdOpts: { count?: string; json?: boolean }) => {
     const opts = program.opts();
     const count = parseInt(cmdOpts.count || '10', 10);
-    const sweetistics = resolveSweetisticsConfig(opts);
+    const sweetistics = resolveSweetisticsConfig({
+      sweetisticsApiKey: opts.sweetisticsApiKey || config.sweetisticsApiKey,
+      sweetisticsBaseUrl: opts.sweetisticsBaseUrl || config.sweetisticsBaseUrl,
+    });
     const engine = resolveEngineMode(opts.engine);
     const useSweetistics = shouldUseSweetistics(engine, Boolean(sweetistics.apiKey));
 
@@ -439,7 +535,8 @@ program
     const { cookies, warnings } = await resolveCredentials({
       authToken: opts.authToken,
       ct0: opts.ct0,
-      chromeProfile: opts.chromeProfile,
+      chromeProfile: opts.chromeProfile || config.chromeProfile,
+      firefoxProfile: opts.firefoxProfile || config.firefoxProfile,
     });
 
     for (const warning of warnings) {
@@ -516,6 +613,71 @@ program
     }
   });
 
+// Whoami command - show the logged-in account
+program
+  .command('whoami')
+  .description('Show which Twitter account the current credentials belong to')
+  .action(async () => {
+    const opts = program.opts();
+    const sweetistics = resolveSweetisticsConfig(opts);
+    const engine = resolveEngineMode(opts.engine);
+    const useSweetistics = shouldUseSweetistics(engine, Boolean(sweetistics.apiKey));
+
+    if (useSweetistics) {
+      if (!sweetistics.apiKey) {
+        console.error('❌ Sweetistics engine selected but no API key provided.');
+        process.exit(1);
+      }
+
+      const client = new SweetisticsClient({ baseUrl: sweetistics.baseUrl, apiKey: sweetistics.apiKey });
+      const result = await client.getCurrentUser();
+
+      if (result.success && result.user) {
+        const handle = result.user.username ? `@${result.user.username}` : '(no handle)';
+        const name = result.user.name || handle;
+        console.log(`🙋 Logged in via Sweetistics as ${handle} (${name})`);
+        console.log(`🪪 User ID: ${result.user.id}`);
+        if (result.user.email) {
+          console.log(`📧 ${result.user.email}`);
+        }
+        return;
+      }
+
+      console.error(`❌ Failed to determine Sweetistics user: ${result.error ?? 'Unknown error'}`);
+      process.exit(1);
+    }
+
+    const { cookies, warnings } = await resolveCredentials({
+      authToken: opts.authToken,
+      ct0: opts.ct0,
+      chromeProfile: opts.chromeProfile,
+    });
+
+    for (const warning of warnings) {
+      console.error(`⚠️  ${warning}`);
+    }
+
+    if (!cookies.authToken || !cookies.ct0) {
+      console.error('❌ Missing required credentials');
+      process.exit(1);
+    }
+
+    if (cookies.source) {
+      console.error(`📍 Using credentials from: ${cookies.source}`);
+    }
+
+    const client = new TwitterClient({ cookies });
+    const result = await client.getCurrentUser();
+
+    if (result.success && result.user) {
+      console.log(`🙋 Logged in as @${result.user.username} (${result.user.name})`);
+      console.log(`🪪 User ID: ${result.user.id}`);
+    } else {
+      console.error(`❌ Failed to determine current user: ${result.error ?? 'Unknown error'}`);
+      process.exit(1);
+    }
+  });
+
 // Check command - verify credentials
 program
   .command('check')
@@ -565,4 +727,10 @@ program
     }
   });
 
+// Show help when invoked without any subcommand
+if (process.argv.length <= 2) {
+  program.outputHelp();
+  process.exit(0);
+}
+
 program.parse();
diff --git a/src/lib/cookies.ts b/src/lib/cookies.ts
index e1bce8a..1825902 100644
--- a/src/lib/cookies.ts
+++ b/src/lib/cookies.ts
@@ -5,7 +5,7 @@
 
 import { execSync } from 'node:child_process';
 import { createDecipheriv, pbkdf2Sync } from 'node:crypto';
-import { copyFileSync, existsSync, mkdtempSync, rmSync } from 'node:fs';
+import { copyFileSync, existsSync, mkdtempSync, readdirSync, rmSync } from 'node:fs';
 import { tmpdir } from 'node:os';
 import { join } from 'node:path';
 
@@ -34,6 +34,26 @@ function getChromeCookiesPath(profile?: string): string {
   return join(home, 'Library', 'Application Support', 'Google', 'Chrome', profileDir, 'Cookies');
 }
 
+function getFirefoxCookiesPath(profile?: string): string | null {
+  const home = process.env.HOME || '';
+  const profilesRoot = join(home, 'Library', 'Application Support', 'Firefox', 'Profiles');
+  if (!existsSync(profilesRoot)) return null;
+
+  if (profile) {
+    const candidate = join(profilesRoot, profile, 'cookies.sqlite');
+    return existsSync(candidate) ? candidate : null;
+  }
+
+  // Pick the default-release profile if present, otherwise first profile dir containing cookies.sqlite
+  const entries = readdirSync(profilesRoot, { withFileTypes: true });
+  const defaultRelease = entries.find((entry) => entry.isDirectory() && entry.name.endsWith('.default-release'));
+  const targetDir = defaultRelease?.name ?? entries.find((e) => e.isDirectory())?.name;
+  if (!targetDir) return null;
+
+  const candidate = join(profilesRoot, targetDir, 'cookies.sqlite');
+  return existsSync(candidate) ? candidate : null;
+}
+
 /**
  * Decrypt Chrome cookie value using macOS keychain
  * Chrome encrypts cookies with a key stored in the keychain
@@ -178,6 +198,74 @@ export async function extractCookiesFromChrome(profile?: string): Promise<Cookie
   return { cookies, warnings };
 }
 
+/**
+ * Extract Twitter cookies from Firefox browser using sqlite3 CLI
+ * @param profile - Firefox profile directory name (optional, auto-detected)
+ */
+export async function extractCookiesFromFirefox(profile?: string): Promise<CookieExtractionResult> {
+  const warnings: string[] = [];
+  const cookies: TwitterCookies = {
+    authToken: null,
+    ct0: null,
+    source: null,
+  };
+
+  const cookiesPath = getFirefoxCookiesPath(profile);
+
+  if (!cookiesPath) {
+    warnings.push('Firefox cookies database not found.');
+    return { cookies, warnings };
+  }
+
+  let tempDir: string | null = null;
+
+  try {
+    tempDir = mkdtempSync(join(tmpdir(), 'twitter-cli-'));
+    const tempDbPath = join(tempDir, 'cookies.sqlite');
+    copyFileSync(cookiesPath, tempDbPath);
+
+    const query = `SELECT name, value FROM moz_cookies WHERE host IN ('.x.com', '.twitter.com', 'x.com', 'twitter.com') AND name IN ('auth_token', 'ct0');`;
+
+    const result = execSync(`sqlite3 -separator '|' "${tempDbPath}" "${query}"`, {
+      encoding: 'utf8',
+      maxBuffer: 1024 * 1024,
+    }).trim();
+
+    if (result) {
+      for (const line of result.split('\n')) {
+        const [name, value] = line.split('|');
+        if (!name || !value) continue;
+        if (name === 'auth_token' && !cookies.authToken) {
+          cookies.authToken = value;
+        } else if (name === 'ct0' && !cookies.ct0) {
+          cookies.ct0 = value;
+        }
+      }
+    }
+
+    if (cookies.authToken || cookies.ct0) {
+      cookies.source = profile ? `Firefox profile "${profile}"` : 'Firefox default profile';
+    }
+  } catch (error) {
+    const message = error instanceof Error ? error.message : String(error);
+    warnings.push(`Failed to read Firefox cookies: ${message}`);
+  } finally {
+    if (tempDir) {
+      try {
+        rmSync(tempDir, { recursive: true, force: true });
+      } catch {
+        // ignore cleanup errors
+      }
+    }
+  }
+
+  if (!cookies.authToken && !cookies.ct0) {
+    warnings.push('No Twitter cookies found in Firefox. Make sure you are logged into x.com in Firefox.');
+  }
+
+  return { cookies, warnings };
+}
+
 /**
  * Resolve Twitter credentials from multiple sources
  * Priority: CLI args > environment variables > Chrome cookies
@@ -186,6 +274,7 @@ export async function resolveCredentials(options: {
   authToken?: string;
   ct0?: string;
   chromeProfile?: string;
+  firefoxProfile?: string;
 }): Promise<CookieExtractionResult> {
   const warnings: string[] = [];
   const cookies: TwitterCookies = {
@@ -245,12 +334,27 @@ export async function resolveCredentials(options: {
     }
   }
 
+  // 4. Firefox cookies (fallback if still missing)
+  if (!cookies.authToken || !cookies.ct0) {
+    const firefoxResult = await extractCookiesFromFirefox(options.firefoxProfile);
+    warnings.push(...firefoxResult.warnings);
+
+    if (!cookies.authToken && firefoxResult.cookies.authToken) {
+      cookies.authToken = firefoxResult.cookies.authToken;
+      cookies.source = firefoxResult.cookies.source;
+    }
+    if (!cookies.ct0 && firefoxResult.cookies.ct0) {
+      cookies.ct0 = firefoxResult.cookies.ct0;
+      if (!cookies.source) cookies.source = firefoxResult.cookies.source;
+    }
+  }
+
   // Validation
   if (!cookies.authToken) {
-    warnings.push('Missing auth_token - provide via --auth-token, AUTH_TOKEN env var, or login to x.com in Chrome');
+    warnings.push('Missing auth_token - provide via --auth-token, AUTH_TOKEN env var, or login to x.com in Chrome/Firefox');
   }
   if (!cookies.ct0) {
-    warnings.push('Missing ct0 - provide via --ct0, CT0 env var, or login to x.com in Chrome');
+    warnings.push('Missing ct0 - provide via --ct0, CT0 env var, or login to x.com in Chrome/Firefox');
   }
 
   return { cookies, warnings };
diff --git a/src/lib/sweetistics-client.ts b/src/lib/sweetistics-client.ts
index d128acb..609a937 100644
--- a/src/lib/sweetistics-client.ts
+++ b/src/lib/sweetistics-client.ts
@@ -39,6 +39,18 @@ export interface SweetisticsReadResult {
   error?: string;
 }
 
+export interface SweetisticsUserResult {
+  success: boolean;
+  user?: {
+    id: string;
+    username?: string | null;
+    name?: string | null;
+    email?: string | null;
+    profileImageUrl?: string | null;
+  };
+  error?: string;
+}
+
 type TrpcResponseEnvelope = { result?: { data?: unknown; error?: unknown } };
 
 function normalizeBaseUrl(value: string): string {
@@ -244,6 +256,80 @@ export class SweetisticsClient {
     return { success: true, tweets };
   }
 
+  async getCurrentUser(): Promise<SweetisticsUserResult> {
+    const headers = {
+      authorization: `Bearer ${this.apiKey}`,
+      'content-type': 'application/json',
+      ...(this.userAgent ? { 'user-agent': this.userAgent } : {}),
+    } satisfies Record<string, string>;
+
+    let response = await fetch(`${this.baseUrl}/api/trpc/user.getCurrent?batch=1`, {
+      method: 'POST',
+      headers,
+      body: JSON.stringify({ 0: { json: null } }),
+    });
+
+    // Some deployments only allow GET for queries; fall back if POST is not allowed
+    if (response.status === 405) {
+      response = await fetch(`${this.baseUrl}/api/trpc/user.getCurrent?input=${encodeURIComponent('null')}`, {
+        method: 'GET',
+        headers,
+      });
+    }
+
+    if (!response.ok) {
+      return { success: false, error: `HTTP ${response.status}` };
+    }
+
+    let body: any;
+    try {
+      body = await response.json();
+    } catch (error) {
+      return {
+        success: false,
+        error: `Sweetistics response parse failed: ${error instanceof Error ? error.message : String(error)}`,
+      };
+    }
+
+    const envelope = Array.isArray(body) ? body[0] : body;
+    const maybeError = envelope?.error?.message || envelope?.result?.error?.message;
+    if (maybeError) {
+      return { success: false, error: String(maybeError) };
+    }
+
+    let data = envelope?.result?.data?.json ?? envelope?.result?.data ?? envelope?.json ?? envelope;
+
+    try {
+      if (typeof data === 'string') {
+        data = devalueParse(data);
+      } else if (data && typeof data === 'object' && 'json' in (data as Record<string, unknown>)) {
+        const inner = (data as Record<string, unknown>).json;
+        data = typeof inner === 'string' ? devalueParse(inner) : inner;
+      }
+    } catch (error) {
+      return {
+        success: false,
+        error: `Sweetistics response decode failed: ${error instanceof Error ? error.message : String(error)}`,
+      };
+    }
+
+    const user = data && typeof data === 'object' ? data : null;
+    if (!user || typeof (user as any).id !== 'string') {
+      return { success: false, error: 'Malformed user payload from Sweetistics' };
+    }
+
+    return {
+      success: true,
+      user: {
+        id: String((user as any).id),
+        username: (user as any).username ?? (user as any).twitterUsername ?? null,
+        name: (user as any).name ?? null,
+        email: (user as any).email ?? null,
+        profileImageUrl: (user as any).profileImageUrl ?? null,
+      },
+    };
+  }
+
   private async fetchConversation(
     tweetId: string,
     options: { excludeRoot: boolean },
diff --git a/src/lib/twitter-client.ts b/src/lib/twitter-client.ts
index c78cd65..c2b56cc 100644
--- a/src/lib/twitter-client.ts
+++ b/src/lib/twitter-client.ts
@@ -81,6 +81,16 @@ export interface SearchResult {
   error?: string;
 }
 
+export interface CurrentUserResult {
+  success: boolean;
+  user?: {
+    id: string;
+    username: string;
+    name: string;
+  };
+  error?: string;
+}
+
 export interface TwitterClientOptions {
   cookies: TwitterCookies;
   userAgent?: string;
@@ -683,6 +693,130 @@ export class TwitterClient {
     }
   }
 
+  /**
+   * Fetch the account associated with the current cookies
+   */
+  async getCurrentUser(): Promise<CurrentUserResult> {
+    const candidateUrls = [
+      'https://x.com/i/api/account/settings.json',
+      'https://api.twitter.com/1.1/account/settings.json',
+      'https://x.com/i/api/account/verify_credentials.json?skip_status=true&include_entities=false',
+      'https://api.twitter.com/1.1/account/verify_credentials.json?skip_status=true&include_entities=false',
+    ];
+
+    let lastError: string | undefined;
+
+    for (const url of candidateUrls) {
+      try {
+        const response = await fetch(url, {
+          method: 'GET',
+          headers: this.getHeaders(),
+        });
+
+        if (!response.ok) {
+          const text = await response.text();
+          lastError = `HTTP ${response.status}: ${text.slice(0, 200)}`;
+          continue;
+        }
+
+        let data: any;
+        try {
+          data = await response.json();
+        } catch (error) {
+          lastError = error instanceof Error ? error.message : String(error);
+          continue;
+        }
+
+        const username =
+          typeof data?.screen_name === 'string'
+            ? data.screen_name
+            : typeof data?.user?.screen_name === 'string'
+              ? data.user.screen_name
+              : null;
+
+        const name =
+          typeof data?.name === 'string'
+            ? data.name
+            : typeof data?.user?.name === 'string'
+              ? data.user.name
+              : username ?? '';
+
+        const userId =
+          typeof data?.user_id === 'string'
+            ? data.user_id
+            : typeof data?.user_id_str === 'string'
+              ? data.user_id_str
+              : typeof data?.user?.id_str === 'string'
+                ? data.user.id_str
+                : typeof data?.user?.id === 'string'
+                  ? data.user.id
+                  : null;
+
+        if (username && userId) {
+          return {
+            success: true,
+            user: {
+              id: userId,
+              username,
+              name: name || username,
+            },
+          };
+        }
+
+        lastError = 'Could not determine current user from response';
+      } catch (error) {
+        lastError = error instanceof Error ? error.message : String(error);
+      }
+    }
+
+    // Fallback: scrape the authenticated settings page (HTML) for screen_name/user_id
+    const profilePages = ['https://x.com/settings/account', 'https://twitter.com/settings/account'];
+    for (const page of profilePages) {
+      try {
+        const response = await fetch(page, {
+          headers: {
+            cookie: `auth_token=${this.authToken}; ct0=${this.ct0}`,
+            'user-agent': this.userAgent,
+          },
+        });
+
+        if (!response.ok) {
+          lastError = `HTTP ${response.status} (settings page)`;
+          continue;
+        }
+
+        const html = await response.text();
+        const usernameMatch = html.match(/"screen_name":"([^"]+)"/);
+        const idMatch = html.match(/"user_id"\s*:\s*"(\d+)"/);
+        const nameMatch = html.match(/"name":"([^"\\]*(?:\\.[^"\\]*)*)"/);
+
+        const username = usernameMatch?.[1];
+        const userId = idMatch?.[1];
+        const name = nameMatch?.[1]?.replace(/\\"/g, '"');
+
+        if (username && userId) {
+          return {
+            success: true,
+            user: {
+              id: userId,
+              username,
+              name: name || username,
+            },
+          };
+        }
+
+        lastError = 'Could not parse settings page for user info';
+      } catch (error) {
+        lastError = error instanceof Error ? error.message : String(error);
+      }
+    }
+
+    return {
+      success: false,
+      error: lastError ?? 'Unknown error fetching current user',
+    };
+  }
+
   /**
    * Get replies to a tweet by ID
    */
diff --git a/tests/cookies.test.ts b/tests/cookies.test.ts
index 6f1ef79..211e646 100644
--- a/tests/cookies.test.ts
+++ b/tests/cookies.test.ts
@@ -98,9 +98,11 @@ describe('cookies', () => {
       const result = await resolveCredentials({});
 
       expect(result.warnings).toContain(
-        'Missing auth_token - provide via --auth-token, AUTH_TOKEN env var, or login to x.com in Chrome',
+        'Missing auth_token - provide via --auth-token, AUTH_TOKEN env var, or login to x.com in Chrome/Firefox',
+      );
+      expect(result.warnings).toContain(
+        'Missing ct0 - provide via --ct0, CT0 env var, or login to x.com in Chrome/Firefox',
       );
-      expect(result.warnings).toContain('Missing ct0 - provide via --ct0, CT0 env var, or login to x.com in Chrome');
     });
   });
 });
diff --git a/tests/sweetistics-client.test.ts b/tests/sweetistics-client.test.ts
index ee3c2ad..96c3bfc 100644
--- a/tests/sweetistics-client.test.ts
+++ b/tests/sweetistics-client.test.ts
@@ -53,12 +53,10 @@ describe('SweetisticsClient', () => {
       ok: true,
       status: 200,
       json: async () => ({
-        success: true,
-        tweet: {
-          id: '1',
-          text: 'hi',
-          author: { username: 'u', name: 'User' },
-        },
+        id: '1',
+        text: 'hi',
+        author: { username: 'u', name: 'User' },
+        metrics: { likeCount: 5 },
       }),
     });
     globalThis.fetch = fetchMock as unknown as typeof fetch;
@@ -69,17 +67,35 @@ describe('SweetisticsClient', () => {
     expect(result.success).toBe(true);
     expect(result.tweet?.id).toBe('1');
     const [url, init] = fetchMock.mock.calls[0];
-    expect(url).toBe('https://api.example.com/api/twitter/tweet/1');
+    expect(url).toBe('https://api.example.com/api/tweets/1');
     expect((init as RequestInit).headers).toMatchObject({ authorization: 'Bearer sweet-test' });
   });
 
   it('fetches replies', async () => {
+    const conversationPayload = {
+      tweetIds: ['1', '2'],
+      tweets: {
+        1: {
+          id: '1',
+          text: 'root',
+          author: { username: 'root', name: 'Root' },
+          conversationId: 'c1',
+        },
+        2: {
+          id: '2',
+          text: 'reply',
+          author: { username: 'reply', name: 'Reply' },
+          conversationId: 'c1',
+          inReplyToStatusId: '1',
+        },
+      },
+    };
+
     const fetchMock = vi.fn().mockResolvedValue({
       ok: true,
       status: 200,
       json: async () => ({
-        success: true,
-        tweets: [{ id: '2', text: 'reply', author: { username: 'r', name: 'Reply' } }],
+        result: { data: conversationPayload },
       }),
     });
     globalThis.fetch = fetchMock as unknown as typeof fetch;
@@ -90,17 +106,24 @@ describe('SweetisticsClient', () => {
     expect(result.success).toBe(true);
     expect(result.tweets?.[0].id).toBe('2');
     const [url, init] = fetchMock.mock.calls[0];
-    expect(url).toBe('https://api.example.com/api/twitter/tweet/1/replies');
+    expect(url).toContain('/api/trpc/tweets.getConversation');
     expect((init as RequestInit).headers).toMatchObject({ authorization: 'Bearer sweet-test' });
   });
 
   it('fetches thread', async () => {
+    const conversationPayload = {
+      tweetIds: ['1', '2'],
+      tweets: {
+        1: { id: '1', text: 'root', author: { username: 'root', name: 'Root' }, conversationId: 'c1' },
+        2: { id: '2', text: 'reply', author: { username: 'reply', name: 'Reply' }, conversationId: 'c1' },
+      },
+    };
+
     const fetchMock = vi.fn().mockResolvedValue({
       ok: true,
       status: 200,
       json: async () => ({
-        success: true,
-        tweets: [{ id: '1', text: 'root', author: { username: 'u', name: 'User' } }],
+        result: { data: conversationPayload },
       }),
     });
     globalThis.fetch = fetchMock as unknown as typeof fetch;
@@ -109,20 +132,32 @@ describe('SweetisticsClient', () => {
     const result = await client.thread('1');
 
     expect(result.success).toBe(true);
-    expect(result.tweets?.length).toBe(1);
+    expect(result.tweets?.length).toBe(2);
     const [url, init] = fetchMock.mock.calls[0];
-    expect(url).toBe('https://api.example.com/api/twitter/tweet/1/thread');
+    expect(url).toContain('/api/trpc/tweets.getConversation');
     expect((init as RequestInit).headers).toMatchObject({ authorization: 'Bearer sweet-test' });
   });
 
   it('searches tweets', async () => {
+    const searchPayload = {
+      tweets: {
+        items: [
+          {
+            id: '3',
+            text: 'needle',
+            authorUsername: 'n',
+            authorName: 'Needle',
+            createdAt: '2024-01-01',
+            metrics: { replyCount: 1, retweetCount: 2, likeCount: 3 },
+          },
+        ],
+      },
+    };
+
     const fetchMock = vi.fn().mockResolvedValue({
       ok: true,
       status: 200,
-      json: async () => ({
-        success: true,
-        tweets: [{ id: '3', text: 'needle', author: { username: 'n', name: 'Needle' } }],
-      }),
+      json: async () => [{ result: { data: searchPayload } }],
     });
     globalThis.fetch = fetchMock as unknown as typeof fetch;
 
@@ -131,22 +166,76 @@ describe('SweetisticsClient', () => {
 
     expect(result.success).toBe(true);
     expect(result.tweets?.[0].id).toBe('3');
-    const [url] = fetchMock.mock.calls[0];
-    expect(url).toBe('https://api.example.com/api/twitter/search?q=needle&count=5');
-    const [, init] = fetchMock.mock.calls[0];
+    const [url, init] = fetchMock.mock.calls[0];
+    expect(url).toContain('/api/trpc/search.execute');
     expect((init as RequestInit).headers).toMatchObject({ authorization: 'Bearer sweet-test' });
   });
 
-  it('propagates Sweetistics error message', async () => {
+  it('fetches current user', async () => {
     const fetchMock = vi.fn().mockResolvedValue({
-      ok: false,
-      status: 500,
-      json: async () => ({ success: false, error: 'boom' }),
+      ok: true,
+      status: 200,
+      json: async () => [{ result: { data: { json: { id: 'u1', username: 'tester', name: 'Test User' } } } }],
     });
     globalThis.fetch = fetchMock as unknown as typeof fetch;
 
     const client = new SweetisticsClient({ baseUrl: 'https://api.example.com', apiKey: 'sweet-test' });
-    const result = await client.read('1');
+    const result = await client.getCurrentUser();
+
+    expect(result.success).toBe(true);
+    expect(result.user?.id).toBe('u1');
+    expect(result.user?.username).toBe('tester');
+    const [url, init] = fetchMock.mock.calls[0];
+    expect(url).toBe('https://api.example.com/api/trpc/user.getCurrent?batch=1');
+    expect((init as RequestInit).headers).toMatchObject({ authorization: 'Bearer sweet-test' });
+  });
+
+  it('falls back to GET when POST is not allowed', async () => {
+    const fetchMock = vi
+      .fn()
+      .mockResolvedValueOnce({ ok: false, status: 405, json: async () => ({}) })
+      .mockResolvedValueOnce({
+        ok: true,
+        status: 200,
+        json: async () => ({ result: { data: { json: { id: 'u2', username: 'fallback' } } } }),
+      });
+
+    globalThis.fetch = fetchMock as unknown as typeof fetch;
+
+    const client = new SweetisticsClient({ baseUrl: 'https://api.example.com', apiKey: 'sweet-test' });
+    const result = await client.getCurrentUser();
+
+    expect(result.success).toBe(true);
+    expect(result.user?.id).toBe('u2');
+    expect(fetchMock).toHaveBeenCalledTimes(2);
+    expect(fetchMock.mock.calls[1][0]).toContain('input=null');
+  });
+
+  it('propagates Sweetistics user errors', async () => {
+    const fetchMock = vi.fn().mockResolvedValue({
+      ok: true,
+      status: 200,
+      json: async () => [{ result: { error: { message: 'bad key' } } }],
+    });
+    globalThis.fetch = fetchMock as unknown as typeof fetch;
+
+    const client = new SweetisticsClient({ baseUrl: 'https://api.example.com', apiKey: 'sweet-test' });
+    const result = await client.getCurrentUser();
+
+    expect(result.success).toBe(false);
+    expect(result.error).toBe('bad key');
+  });
+
+  it('propagates Sweetistics error message', async () => {
+    const fetchMock = vi.fn().mockResolvedValue({
+      ok: true,
+      status: 500,
+      json: async () => [{ error: { message: 'boom' } }],
+    });
+    globalThis.fetch = fetchMock as unknown as typeof fetch;
+
+    const client = new SweetisticsClient({ baseUrl: 'https://api.example.com', apiKey: 'sweet-test' });
+    const result = await client.search('needle', 1);
 
     expect(result.success).toBe(false);
     expect(result.error).toBe('boom');
diff --git a/tests/twitter-client.test.ts b/tests/twitter-client.test.ts
index b366d7c..dd44f29 100644
--- a/tests/twitter-client.test.ts
+++ b/tests/twitter-client.test.ts
@@ -296,4 +296,82 @@ describe('TwitterClient', () => {
       expect(result.error).toContain('HTTP 404');
     });
   });
+
+  describe('getCurrentUser', () => {
+    let mockFetch: ReturnType<typeof vi.fn>;
+
+    beforeEach(() => {
+      mockFetch = vi.fn();
+      global.fetch = mockFetch as any;
+    });
+
+    it('returns mapped user details when present', async () => {
+      mockFetch.mockResolvedValue({
+        ok: true,
+        status: 200,
+        json: async () => ({
+          user_id: '12345',
+          screen_name: 'tester',
+          name: 'Test User',
+        }),
+      });
+
+      const client = new TwitterClient({ cookies: validCookies });
+      const result = await client.getCurrentUser();
+
+      expect(result.success).toBe(true);
+      expect(result.user).toEqual({ id: '12345', username: 'tester', name: 'Test User' });
+      expect(mockFetch).toHaveBeenCalledWith(expect.stringContaining('account/settings'), expect.any(Object));
+    });
+
+    it('returns error when response lacks identifiers', async () => {
+      mockFetch.mockImplementation(async () => ({
+        ok: true,
+        status: 200,
+        json: async () => ({ language: 'en' }),
+        text: async () => '{"language":"en"}',
+      }));
+
+      const client = new TwitterClient({ cookies: validCookies });
+      const result = await client.getCurrentUser();
+
+      expect(result.success).toBe(false);
+      expect(result.error).toContain('Could not');
+    });
+
+    it('surfaces HTTP errors', async () => {
+      mockFetch.mockImplementation(async () => ({
+        ok: false,
+        status: 401,
+        text: async () => 'Unauthorized',
+      }));
+
+      const client = new TwitterClient({ cookies: validCookies });
+      const result = await client.getCurrentUser();
+
+      expect(result.success).toBe(false);
+      expect(result.error).toContain('HTTP 401');
+    });
+
+    it('uses HTML fallback when API endpoints 404', async () => {
+      mockFetch
+        .mockResolvedValueOnce({ ok: false, status: 404, text: async () => 'not found' })
+        .mockResolvedValueOnce({ ok: false, status: 404, text: async () => 'not found' })
+        .mockResolvedValueOnce({ ok: false, status: 404, text: async () => 'not found' })
+        .mockResolvedValueOnce({ ok: false, status: 404, text: async () => 'not found' })
+        .mockResolvedValueOnce({
+          ok: true,
+          status: 200,
+          text: async () => '<html>"screen_name":"fallback","user_id":"999"</html>',
+        });
+
+      const client = new TwitterClient({ cookies: validCookies });
+      const result = await client.getCurrentUser();
+
+      expect(result.success).toBe(true);
+      expect(result.user?.username).toBe('fallback');
+      expect(result.user?.id).toBe('999');
+      expect(mockFetch).toHaveBeenCalledTimes(5);
+    });
+  });
 });