diff --git a/index.ts b/index.ts
index 4d962d1..27a681f 100644
--- a/index.ts
+++ b/index.ts
@@ -1,995 +1,274 @@
 #!/usr/bin/env bun
 
-import * as readline from "node:readline";
-import { loadConfig, saveConfig } from "./src/config";
-import {
-  isGitRepo,
-  getRepoRoot,
-  getStagedFiles,
-  getUnstagedFiles,
-  getStagedDiff,
-  getRecentCommits,
-  stageFiles,
-  commit,
-} from "./src/git";
-import { selectFiles } from "./src/selector";
+// gai — AI-powered git commit and PR helper
+// v0.2.0
+
+import { runCLI, registerCommands, formatHelp, type CommandDef, type ParsedArgs } from "./src/cli";
+import { handleCommit } from "./src/commands/commit";
+import { handlePR } from "./src/commands/pr";
+import { handleConfig } from "./src/commands/config";
+import { handleExplain } from "./src/commands/explain";
+import { handleReview } from "./src/commands/review";
+import { handleChangelog } from "./src/commands/changelog";
+import { handleSuggest } from "./src/commands/suggest";
+import { setColorEnabled } from "./src/terminal";
+import { BOLD, GREEN, CYAN, DIM, RESET } from "./src/terminal";
+import { isStdinTTY, initTTY } from "./src/tty";
 import { BACK, selectOne } from "./src/menu";
-import type { PromptBack } from "./src/menu";
-import { collectProjectContext } from "./src/context";
-import { buildPrompt, SYSTEM_PROMPT } from "./src/prompt";
-import { generateCommitMessage } from "./src/ai";
-import { copyToClipboard } from "./src/clipboard";
-import { BOLD, GREEN, YELLOW, CYAN, RED, DIM, RESET } from "./src/terminal";
-import type { Config } from "./src/types";
-import {
-  getDefaultBranch,
-  getBranchName,
-  getBranchPushStatus,
-  pushCurrentBranch,
-  getBranchCommits,
-  getBranchDiff,
-  detectPlatform,
-  getRemoteHostname,
-  createPR,
-} from "./src/pr";
-import type { Platform } from "./src/pr";
-import { PR_SYSTEM_PROMPT, buildPRPrompt } from "./src/prompt";
-import { generatePRMessage } from "./src/ai";
 
-const args = process.argv.slice(2);
+// ── Interactive Menu (default, no subcommand) ─────────────────────────
 
-function showHelp() {
-  console.log(`
-${BOLD}gai${RESET} — AI-powered git commit message generator
-
-${BOLD}Usage:${RESET}
-  gai                Open interactive menu
-  gai commit         Generate commit message for staged/changed files
-  gai commit --auto  Auto-stage all changed files
-  gai commit -d      Generate message without committing
-  gai pr             Create a PR with AI-generated title and body
-  gai pr --draft     Create a draft PR
-  gai config         Configure API settings
-  gai --help         Show this help message
-  gai --version      Show version
-
-${BOLD}Configuration:${RESET}
-  Set via ${CYAN}gai config${RESET} or environment variables:
-    GAI_API_KEY      OpenAI-compatible API key
-    GAI_API_BASE     API base URL (default: https://api.deepseek.com/v1)
-    GAI_MODEL        Model name (default: deepseek-chat)
-    GAI_MAX_TOKENS   Max tokens (default: 500)
-    GAI_TEMPERATURE  Temperature (default: 0.7)
-`);
-}
-
-function ask(question: string): Promise<string> {
-  const rl = readline.createInterface({
-    input: process.stdin,
-    output: process.stdout,
-  });
-  return new Promise((resolve) => {
-    rl.question(question, (answer) => {
-      rl.close();
-      resolve(answer.trim());
-    });
-  });
-}
-
-type ConfigKey = keyof Config;
-
-interface ConfigField {
-  key: ConfigKey;
-  label: string;
-  format: (config: Config) => string;
-  initialEditValue: (config: Config) => string;
-  parse: (value: string) => { value: Config[ConfigKey] } | { error: string };
-}
-
-const CONFIG_FIELDS: ConfigField[] = [
-  {
-    key: "apiKey",
-    label: "API Key",
-    format: (config) =>
-      config.apiKey ? `****${config.apiKey.slice(-4)}` : `${YELLOW}(not set)${RESET}`,
-    initialEditValue: () => "",
-    parse: (value) => ({ value }),
-  },
-  {
-    key: "apiBase",
-    label: "API Base",
-    format: (config) => config.apiBase,
-    initialEditValue: (config) => config.apiBase,
-    parse: (value) => ({ value }),
-  },
-  {
-    key: "model",
-    label: "Model",
-    format: (config) => config.model,
-    initialEditValue: (config) => config.model,
-    parse: (value) => ({ value }),
-  },
-  {
-    key: "maxTokens",
-    label: "Max Tokens",
-    format: (config) => String(config.maxTokens),
-    initialEditValue: (config) => String(config.maxTokens),
-    parse: (value) => {
-      const parsed = Number(value);
-      if (!Number.isInteger(parsed) || parsed <= 0) {
-        return { error: "Max Tokens must be a positive integer." };
-      }
-      return { value: parsed };
-    },
-  },
-  {
-    key: "temperature",
-    label: "Temperature",
-    format: (config) => String(config.temperature),
-    initialEditValue: (config) => String(config.temperature),
-    parse: (value) => {
-      const parsed = Number(value);
-      if (!Number.isFinite(parsed)) {
-        return { error: "Temperature must be a finite number." };
-      }
-      return { value: parsed };
-    },
-  },
-];
-
-function visibleLength(value: string) {
-  return value.replace(/\x1b\[[0-9;]*m/g, "").length;
-}
-
-function clearLine() {
-  process.stdout.write("\r\x1b[2K");
-}
-
-function moveUp(lines: number) {
-  if (lines > 0) process.stdout.write(`\x1b[${lines}A`);
-}
-
-function renderConfigPage(
-  config: Config,
-  cursor: number,
-  previousLines: number,
-  status: string | null,
-  editState: { buffer: string; cursor: number } | null,
-) {
-  if (previousLines > 0) {
-    for (let i = 0; i < previousLines; i++) {
-      clearLine();
-      process.stdout.write("\n");
-    }
-    moveUp(previousLines);
-  }
-
-  const labelWidth = Math.max(...CONFIG_FIELDS.map((field) => field.label.length)) + 2;
-  const lines = [
-    "",
-    `  ${BOLD}Configuration${RESET}`,
-    editState
-      ? `  ${DIM}editing · enter save · esc cancel · ctrl+c cancel${RESET}`
-      : `  ${DIM}↑/↓ navigate · space edit · ←/backspace back · ctrl+c cancel${RESET}`,
-    "",
-  ];
-
-  let activeValueOffset = 0;
-  for (let i = 0; i < CONFIG_FIELDS.length; i++) {
-    const field = CONFIG_FIELDS[i]!;
-    const active = i === cursor;
-    const pointer = active ? `${CYAN}❯${RESET}` : " ";
-    const marker = active ? `${GREEN}●${RESET}` : `${DIM}○${RESET}`;
-    const label = active ? `${BOLD}${field.label}${RESET}` : field.label;
-    const padding = " ".repeat(Math.max(1, labelWidth - visibleLength(field.label)));
-    const value = active && editState ? editState.buffer : field.format(config);
-    if (active && editState) {
-      activeValueOffset = visibleLength(`  ${pointer} ${marker} ${label}${padding}`);
-    }
-    lines.push(`  ${pointer} ${marker} ${label}${padding}${value}`);
-  }
-
-  if (status) {
-    lines.push("", `  ${status}`);
-  }
-
-  for (const line of lines) {
-    process.stdout.write(`${line}\n`);
-  }
-  if (editState) {
-    moveUp(lines.length - (4 + cursor));
-    const column = activeValueOffset + editState.cursor;
-    process.stdout.write(`\r${column > 0 ? `\x1b[${column}C` : ""}`);
-  } else {
-    moveUp(lines.length);
-  }
-  return lines.length;
-}
-
-async function handleConfig(): Promise<"done" | "back"> {
-  if (process.stdin.isTTY !== true) {
-    console.error(`  ${RED}Error: Configuration requires a TTY.${RESET}`);
-    process.exit(1);
-  }
-
-  let config = await loadConfig();
-  let cursor = 0;
-  let renderedLines = 0;
-  let escapeBuf = "";
-  let status: string | null = null;
-  let editState: { buffer: string; cursor: number } | null = null;
-  let renderedCursorRow = 0;
-  const wasRaw = process.stdin.isRaw;
-
-  if (wasRaw !== true) process.stdin.setRawMode(true);
-  process.stdin.resume();
-  process.stdout.write("\x1b[?25l");
-
-  const render = () => {
-    moveUp(renderedCursorRow);
-    renderedLines = renderConfigPage(config, cursor, renderedLines, status, editState);
-    renderedCursorRow = editState ? 4 + cursor : 0;
-    process.stdout.write(editState ? "\x1b[?25h" : "\x1b[?25l");
-  };
-
-  render();
-
-  return new Promise((resolve) => {
-    const finish = (value: "done" | "back") => {
-      process.stdin.setRawMode(wasRaw === true);
-      process.stdin.pause();
-      process.stdin.removeListener("data", onData);
-      moveUp(renderedCursorRow);
-      for (let i = 0; i < renderedLines; i++) {
-        clearLine();
-        process.stdout.write("\n");
-      }
-      moveUp(renderedLines);
-      process.stdout.write("\x1b[?25h");
-      resolve(value);
-    };
-
-    const saveEdit = async () => {
-      if (!editState) return;
-      const field = CONFIG_FIELDS[cursor]!;
-      const value = editState.buffer.trim();
-      editState = null;
-
-      if (value === "") {
-        status = `${DIM}No changes.${RESET}`;
-      } else {
-        const parsed = field.parse(value);
-        if ("error" in parsed) {
-          status = `${RED}${parsed.error}${RESET}`;
-        } else {
-          await saveConfig({ [field.key]: parsed.value } as Partial<Config>);
-          config = await loadConfig();
-          status = `${GREEN}${field.label} saved.${RESET}`;
-        }
-      }
-
-      render();
-    };
-
-    const onData = (data: Buffer) => {
-      const key = data.toString();
-      const UP = "\x1b[A";
-      const DOWN = "\x1b[B";
-      const LEFT = "\x1b[D";
-      const ALT_UP = "\x1bOA";
-      const ALT_DOWN = "\x1bOB";
-      const ALT_LEFT = "\x1bOD";
-      const SPACE = " ";
-      const ENTER = "\r";
-      const ESC = "\x1b";
-      const RIGHT = "\x1b[C";
-      const ALT_RIGHT = "\x1bOC";
-      const CTRL_C = "\x03";
-      const BACKSPACE = "\x7f";
-
-      if (editState) {
-        if (key === CTRL_C || key === ESC) {
-          editState = null;
-          status = `${DIM}No changes.${RESET}`;
-          render();
-          return;
-        }
-        if (key === ENTER) {
-          void saveEdit();
-          return;
-        }
-        if (key === "\x01") {
-          editState.cursor = 0;
-          render();
-          return;
-        }
-        if (key === "\x05") {
-          editState.cursor = editState.buffer.length;
-          render();
-          return;
-        }
-        if (key === "\x0b") {
-          editState.buffer = editState.buffer.slice(0, editState.cursor);
-          render();
-          return;
-        }
-        if (key === "\x15") {
-          editState.buffer = editState.buffer.slice(editState.cursor);
-          editState.cursor = 0;
-          render();
-          return;
-        }
-        if (key === BACKSPACE) {
-          if (editState.cursor > 0) {
-            editState.buffer =
-              editState.buffer.slice(0, editState.cursor - 1) +
-              editState.buffer.slice(editState.cursor);
-            editState.cursor--;
-            render();
-          }
-          return;
-        }
-        if (key === LEFT || key === ALT_LEFT) {
-          if (editState.cursor > 0) editState.cursor--;
-          render();
-          return;
-        }
-        if (key === RIGHT || key === ALT_RIGHT) {
-          if (editState.cursor < editState.buffer.length) editState.cursor++;
-          render();
-          return;
-        }
-        if (key.startsWith("\x1b[")) {
-          if (key === "\x1b[H" || key === "\x1b[1~") {
-            editState.cursor = 0;
-          } else if (key === "\x1b[F" || key === "\x1b[4~") {
-            editState.cursor = editState.buffer.length;
-          } else if (key === "\x1b[3~" && editState.cursor < editState.buffer.length) {
-            editState.buffer =
-              editState.buffer.slice(0, editState.cursor) +
-              editState.buffer.slice(editState.cursor + 1);
-          }
-          render();
-          return;
-        }
-        if (key >= " " && key !== "\x7f") {
-          editState.buffer =
-            editState.buffer.slice(0, editState.cursor) +
-            key +
-            editState.buffer.slice(editState.cursor);
-          editState.cursor += key.length;
-          render();
-        }
-        return;
-      }
-
-      const action = (() => {
-        if (key === UP || key === ALT_UP) return "up";
-        if (key === DOWN || key === ALT_DOWN) return "down";
-        if (key === LEFT || key === ALT_LEFT || key === BACKSPACE) return "back";
-        if (key === SPACE) return "edit";
-        if (key === CTRL_C) return "cancel";
-        if (key === "\x1b" || key.startsWith("\x1b[")) {
-          escapeBuf = key;
-          return null;
-        }
-        if (escapeBuf) {
-          const next = escapeBuf + key;
-          escapeBuf = /^[A-Za-z~]$/.test(key) || next.length > 8 ? "" : next;
-          if (next === UP || next === ALT_UP) return "up";
-          if (next === DOWN || next === ALT_DOWN) return "down";
-          if (next === LEFT || next === ALT_LEFT) return "back";
-        }
-        return null;
-      })();
-
-      if (action === "cancel") return finish("done");
-      if (action === "back") return finish("back");
-      if (action === "up" && cursor > 0) {
-        cursor--;
-        status = null;
-        render();
-      } else if (action === "down" && cursor < CONFIG_FIELDS.length - 1) {
-        cursor++;
-        status = null;
-        render();
-      } else if (action === "edit") {
-        const value = CONFIG_FIELDS[cursor]!.initialEditValue(config);
-        editState = { buffer: value, cursor: value.length };
-        status = null;
-        render();
-      }
-    };
-
-    process.stdin.on("data", onData);
-  });
-}
-
-async function confirmCommit(message: string): Promise<"y" | "n" | "e"> {
-  console.log(`\n  ${BOLD}Generated commit message:${RESET}`);
-  console.log(`    ${GREEN}${message}${RESET}\n`);
-  const answer = await ask(`  Use this message? [${GREEN}Y${RESET}/n/e] `);
-  const lower = answer.toLowerCase();
-  if (lower === "n") return "n";
-  if (lower === "e") return "e";
-  return "y";
-}
-
-async function editMessage(current: string): Promise<string | null> {
-  if (!process.stdin.isTTY) return null;
-
-  process.stdout.write(`  ${DIM}Edit message (Enter to confirm, Esc to abort):${RESET}\n`);
-
-  const savedRaw = process.stdin.isRaw;
-  process.stdin.setRawMode(true);
-  process.stdin.resume();
-
-  let buffer = current;
-  let cursor = current.length;
-  const ESC = "\x1b";
-  const ENTER = "\r";
-  const CTRL_C = "\x03";
-  const BACKSPACE = "\x7f";
-
-  function render() {
-    process.stdout.write("\x1b[2K\r  > " + buffer);
-    if (cursor < buffer.length) {
-      process.stdout.write(`\x1b[${buffer.length - cursor}D`);
-    }
-  }
-
-  process.stdout.write("  > ");
-  process.stdout.write(buffer);
-
-  return new Promise((resolve) => {
-    let escapeBuf = "";
-
-    function handleSeq(seq: string) {
-      if (seq === "\x1b[D" || seq === "\x1bOD") {
-        if (cursor > 0) {
-          cursor--;
-          process.stdout.write("\x1b[D");
-        }
-      } else if (seq === "\x1b[C" || seq === "\x1bOC") {
-        if (cursor < buffer.length) {
-          cursor++;
-          process.stdout.write("\x1b[C");
-        }
-      } else if (seq === "\x1b[H" || seq === "\x1b[1~" || seq === "\x1bOH") {
-        if (cursor > 0) {
-          process.stdout.write(`\x1b[${cursor}D`);
-          cursor = 0;
-        }
-      } else if (seq === "\x1b[F" || seq === "\x1b[4~" || seq === "\x1bOF") {
-        if (cursor < buffer.length) {
-          process.stdout.write(`\x1b[${buffer.length - cursor}C`);
-          cursor = buffer.length;
-        }
-      } else if (seq === "\x1b[3~") {
-        if (cursor < buffer.length) {
-          buffer = buffer.slice(0, cursor) + buffer.slice(cursor + 1);
-          render();
-        }
-      }
-    }
-
-    process.stdin.on("data", (data: Buffer) => {
-      const key = data.toString();
-
-      if (key === CTRL_C) {
-        process.stdin.setRawMode(savedRaw === true);
-        process.stdin.pause();
-        process.stdin.removeAllListeners("data");
-        process.stdout.write("\n");
-        resolve(null);
-        return;
-      }
-
-      if (key === ESC || key.startsWith("\x1b[")) {
-        escapeBuf = key;
-        if (key.length >= 3) {
-          handleSeq(key);
-          escapeBuf = "";
-        }
-        return;
-      }
-
-      if (escapeBuf) {
-        escapeBuf += key;
-        if (/^[A-Za-z~]$/.test(key)) {
-          handleSeq(escapeBuf);
-          escapeBuf = "";
-        } else if (escapeBuf.length > 8) {
-          escapeBuf = "";
-        }
-        return;
-      }
-
-      if (key === ENTER) {
-        process.stdin.setRawMode(savedRaw === true);
-        process.stdin.pause();
-        process.stdin.removeAllListeners("data");
-        process.stdout.write("\n");
-        const result = buffer.trim();
-        resolve(result || null);
-        return;
-      }
-
-      if (key === BACKSPACE) {
-        if (cursor > 0) {
-          buffer = buffer.slice(0, cursor - 1) + buffer.slice(cursor);
-          cursor--;
-          render();
-        }
-        return;
-      }
-
-      if (key === "\x01") {
-        if (cursor > 0) {
-          process.stdout.write(`\x1b[${cursor}D`);
-          cursor = 0;
-        }
-        return;
-      }
-      if (key === "\x05") {
-        if (cursor < buffer.length) {
-          process.stdout.write(`\x1b[${buffer.length - cursor}C`);
-          cursor = buffer.length;
-        }
-        return;
-      }
-      if (key === "\x0b") {
-        buffer = buffer.slice(0, cursor);
-        render();
-        return;
-      }
-      if (key === "\x15") {
-        buffer = buffer.slice(cursor);
-        cursor = 0;
-        render();
-        return;
-      }
-
-      if (key.charCodeAt(0) >= 32 && key.charCodeAt(0) < 127) {
-        buffer = buffer.slice(0, cursor) + key + buffer.slice(cursor);
-        cursor++;
-        render();
-      }
-    });
-  });
-}
-
-function printCommitResult(
-  result: { branch: string; hash: string; files: number; insertions: number; deletions: number },
-  msg: string,
-) {
-  console.log(`\n  ${GREEN}${BOLD}✔ Committed successfully!${RESET}`);
-
-  const id = result.branch && result.hash
-    ? `${YELLOW}[${result.branch} ${result.hash}]${RESET}`
-    : result.hash
-      ? `${YELLOW}${result.hash}${RESET}`
-      : "";
-  console.log(`    ${id}  ${msg}`);
-
-  const parts: string[] = [];
-  if (result.files > 0) parts.push(`${YELLOW}${result.files} file${result.files > 1 ? "s" : ""} changed${RESET}`);
-  if (result.insertions > 0) parts.push(`${GREEN}${result.insertions} insertion${result.insertions > 1 ? "s" : ""}(+)${RESET}`);
-  if (result.deletions > 0) parts.push(`${RED}${result.deletions} deletion${result.deletions > 1 ? "s" : ""}(-)${RESET}`);
-  if (parts.length > 0) console.log(`    ${parts.join(", ")}`);
-}
-
-interface MenuAction {
-  key: "commit" | "pr" | "config";
-  label: string;
-  description: string;
-}
-
-const MENU_ACTIONS: MenuAction[] = [
-  { key: "commit", label: "commit", description: "Generate AI commit message" },
-  { key: "pr", label: "pr", description: "Create a PR with AI-generated title" },
-  { key: "config", label: "config", description: "Configure API settings" },
-];
-
-async function showMenu(): Promise<void> {
-  if (!process.stdin.isTTY) {
-    console.error(`  ${RED}Error: Interactive menu requires a TTY.${RESET}`);
-    process.exit(1);
+async function showMenu(): Promise<number> {
+  if (!isStdinTTY()) {
+    console.error("Error: Interactive menu requires a TTY. Use --help for usage.");
+    return 1;
   }
 
   while (true) {
     const selected = await selectOne({
       title: "gai",
-      subtitle: "Choose a workflow",
+      subtitle: "AI-powered git helper — choose a workflow",
       allowBack: false,
-      items: MENU_ACTIONS.map((action) => ({
-        label: action.label,
-        value: action.key,
-        description: action.description,
-      })),
+      items: [
+        { label: "commit", value: "commit", description: "Generate AI commit message" },
+        { label: "pr", value: "pr", description: "Create a PR with AI-generated title" },
+        { label: "explain", value: "explain", description: "Explain staged changes in plain language" },
+        { label: "review", value: "review", description: "AI code review of staged changes" },
+        { label: "changelog", value: "changelog", description: "Generate changelog from commits" },
+        { label: "suggest", value: "suggest", description: "Suggest branch name or commit type" },
+        { label: "amend", value: "amend", description: "Amend last commit with AI message" },
+        { label: "config", value: "config", description: "Configure API settings" },
+      ],
     });
 
-    if (selected === null || selected === BACK) return;
+    if (selected === null || selected === BACK) return 0;
 
-    const result =
-      selected === "commit"
-        ? await handleCommit(false, false)
-        : selected === "pr"
-          ? await handlePR(false)
-          : await handleConfig();
+    // Build synthetic args for subcommand handlers
+    const fakeArgs: ParsedArgs = {
+      command: selected,
+      flags: {},
+      positional: [],
+      raw: [],
+      subcommand: {
+        name: selected,
+        description: "",
+        handler: async () => 0,
+      },
+    };
 
-    if (result !== "back") return;
+    let result: number;
+    switch (selected) {
+      case "commit":
+        result = await handleCommit(fakeArgs);
+        break;
+      case "pr":
+        result = await handlePR(fakeArgs);
+        break;
+      case "config":
+        result = await handleConfig(fakeArgs);
+        break;
+      case "explain":
+        result = await handleExplain(fakeArgs);
+        break;
+      case "review":
+        result = await handleReview(fakeArgs);
+        break;
+      case "changelog":
+        result = await handleChangelog(fakeArgs);
+        break;
+      case "suggest":
+        result = await handleSuggest(fakeArgs);
+        break;
+      case "amend":
+        fakeArgs.flags["amend"] = true;
+        result = await handleCommit(fakeArgs);
+        break;
+      default:
+        result = 0;
+    }
+
+    // Return to menu unless they explicitly chose "back"
+    if (result !== 0) return result;
+    // Loop back to menu for another action
   }
 }
 
-async function selectPlatform(
-  hostname: string,
-): Promise<Platform | null | PromptBack> {
-  if (!process.stdin.isTTY) {
-    console.error(`  ${RED}Error: Platform selection requires a TTY.${RESET}`);
-    process.exit(1);
-  }
+// ── Command Definitions ────────────────────────────────────────────────
 
-  return selectOne({
-    title: "Select remote platform",
-    subtitle: `Remote ${hostname} could not be auto-detected`,
-    items: [
-      { label: "GitHub", value: "github" as Platform, description: "Use gh CLI" },
-      { label: "Gitea", value: "gitea" as Platform, description: "Use tea CLI" },
-      { label: "GitLab", value: "gitlab" as Platform, description: "Use glab CLI" },
+const commands = registerCommands(
+  {
+    name: "",
+    description: "Open interactive menu",
+    usage: "gai",
+    handler: async () => showMenu(),
+  } as CommandDef,
+
+  {
+    name: "help",
+    aliases: ["h"],
+    description: "Show help for gai or a specific command",
+    usage: "gai help [command]",
+    handler: async (args: ParsedArgs) => {
+      const commandsMap = registerCommands(...allCommandDefs);
+      const cmdName = args.positional[0] || undefined;
+      console.log(formatHelp(commandsMap, cmdName));
+      return 0;
+    },
+  } as CommandDef,
+
+  {
+    name: "commit",
+    aliases: ["c", "ci"],
+    description: "Generate AI commit message for staged changes",
+    usage: "gai commit [-a|--all] [-d|--dry-run] [-m|--message <msg>] [--amend]",
+    flags: [
+      { long: "all", short: "a", type: "boolean", description: "Auto-stage all changed files" },
+      { long: "auto", type: "boolean", description: "Alias for --all" },
+      { long: "dry-run", short: "d", type: "boolean", description: "Generate message without committing" },
+      { long: "message", short: "m", type: "string", description: "Use provided message (skip AI)" },
+      { long: "amend", type: "boolean", description: "Amend the last commit with AI-generated message" },
     ],
-  });
-}
+    examples: [
+      "gai commit",
+      "gai commit -a",
+      "gai commit -d",
+      "gai commit -m 'fix: typo in README'",
+      "gai commit --amend",
+      "git diff --staged | gai commit",
+    ],
+    handler: handleCommit,
+  },
 
-async function handleCommit(
-  autoMode: boolean,
-  dryRun: boolean,
-): Promise<"done" | "back"> {
-  if (!(await isGitRepo())) {
-    console.error(`  ${RED}Error: Not a git repository.${RESET}`);
-    process.exit(1);
-  }
+  {
+    name: "pr",
+    aliases: ["p"],
+    description: "Create a PR with AI-generated title and body",
+    usage: "gai pr [--draft]",
+    flags: [
+      { long: "draft", type: "boolean", description: "Create as draft PR" },
+    ],
+    examples: [
+      "gai pr",
+      "gai pr --draft",
+    ],
+    handler: handlePR,
+  },
 
-  const stagedFiles = await getStagedFiles();
-  const unstagedFiles = await getUnstagedFiles();
+  {
+    name: "config",
+    aliases: ["cfg"],
+    description: "Configure API settings",
+    usage: "gai config [get <key>|set <key> <value>|list]",
+    flags: [],
+    examples: [
+      "gai config",
+      "gai config list",
+      "gai config get model",
+      "gai config set model gpt-4o",
+    ],
+    handler: handleConfig,
+  },
 
-  if (stagedFiles.length === 0 && unstagedFiles.length === 0) {
-    console.log(`  ${DIM}Nothing to commit. No staged or unstaged changes.${RESET}`);
-    return "done";
-  }
+  {
+    name: "explain",
+    aliases: ["x"],
+    description: "Explain staged changes in plain language",
+    usage: "gai explain [--unstaged]",
+    flags: [
+      { long: "unstaged", short: "u", type: "boolean", description: "Explain unstaged changes instead of staged" },
+      { long: "staged", short: "s", type: "boolean", description: "Explain staged changes (default)" },
+    ],
+    examples: [
+      "gai explain",
+      "gai explain --unstaged",
+      "git diff main..feature | gai explain",
+    ],
+    handler: handleExplain,
+  },
 
-  if (unstagedFiles.length > 0) {
-    if (autoMode) {
-      await stageFiles(unstagedFiles.map((f) => f.path));
-      console.log(
-        `  ${GREEN}Auto-staged ${unstagedFiles.length} file(s).${RESET}`,
-      );
-    } else {
-      const selected = await selectFiles(stagedFiles, unstagedFiles);
-      if (selected === BACK) return "back";
-      if (selected.length > 0) {
-        await stageFiles(selected);
-        console.log(
-          `  ${GREEN}Staged ${selected.length} file(s).${RESET}`,
-        );
-      }
-    }
-  }
+  {
+    name: "review",
+    aliases: ["r", "rv"],
+    description: "AI code review of staged changes",
+    usage: "gai review [--strict|--lenient] [--unstaged]",
+    flags: [
+      { long: "strict", type: "boolean", description: "Thorough review, flag minor issues" },
+      { long: "lenient", type: "boolean", description: "Focus only on major issues" },
+      { long: "unstaged", short: "u", type: "boolean", description: "Review unstaged changes instead of staged" },
+    ],
+    examples: [
+      "gai review",
+      "gai review --strict",
+      "gai review --unstaged",
+      "git diff main..feature | gai review",
+    ],
+    handler: handleReview,
+  },
 
-  const diff = await getStagedDiff();
-  if (!diff) {
-    console.log(`  ${DIM}Nothing to commit. No staged changes to commit.${RESET}`);
-    return "done";
-  }
+  {
+    name: "changelog",
+    aliases: ["cl", "log"],
+    description: "Generate changelog from recent commits",
+    usage: "gai changelog [--from <ref>] [--to <ref>] [--count <n>]",
+    flags: [
+      { long: "from", short: "f", type: "string", description: "Starting ref (tag or commit)" },
+      { long: "to", short: "t", type: "string", description: "Ending ref (default: HEAD)" },
+      { long: "count", short: "n", type: "string", description: "Number of recent commits (default: 20)" },
+    ],
+    examples: [
+      "gai changelog",
+      "gai changelog --from v1.0.0",
+      "gai changelog --from v1.0.0 --to v1.1.0",
+      "gai changelog -n 50",
+    ],
+    handler: handleChangelog,
+  },
 
-  const config = await loadConfig();
+  {
+    name: "suggest",
+    aliases: ["sg"],
+    description: "Suggest branch name or commit type based on changes",
+    usage: "gai suggest [branch|type]",
+    flags: [
+      { long: "unstaged", short: "u", type: "boolean", description: "Use unstaged changes" },
+    ],
+    examples: [
+      "gai suggest branch",
+      "gai suggest type",
+      "git diff | gai suggest branch",
+    ],
+    handler: handleSuggest,
+  },
+);
 
-  if (!config.apiKey) {
-    console.error(
-      `  ${RED}Error: API key not set. Run ${BOLD}gai config${RESET}${RED} to configure.${RESET}`,
-    );
-    process.exit(1);
-  }
+// Keep the defs accessible for help command
+const allCommandDefs = [...commands.values()].filter(
+  (c, i, arr) => arr.findIndex((x) => x.name === c.name) === i,
+);
 
-  const MAX_DIFF_SIZE = 15000;
-  const truncatedDiff =
-    diff.length > MAX_DIFF_SIZE
-      ? diff.substring(0, MAX_DIFF_SIZE) + "\n... (truncated)"
-      : diff;
-
-  const repoRoot = await getRepoRoot();
-  const projectCtx = await collectProjectContext(repoRoot);
-  const recentCommits = await getRecentCommits(10);
-
-  const userPrompt = buildPrompt({
-    readme: projectCtx.readme,
-    packageDescription: projectCtx.packageDescription,
-    structure: projectCtx.structure,
-    recentCommits,
-    diff: truncatedDiff,
-  });
-
-  console.log("\n  Generating commit message...");
-
-  let message: string;
-  try {
-    message = await generateCommitMessage(config, SYSTEM_PROMPT, userPrompt);
-  } catch (err) {
-    console.error(
-      `  ${RED}AI request failed: ${err instanceof Error ? err.message : err}${RESET}`,
-    );
-    process.exit(1);
-  }
-
-  if (dryRun) {
-    console.log(`\n  ${BOLD}Generated commit message:${RESET}`);
-    console.log(`    ${GREEN}${message}${RESET}`);
-    await copyToClipboard(message);
-    console.log(`\n  ${DIM}(dry-run, message copied to clipboard)${RESET}`);
-    return "done";
-  }
-
-  const action = await confirmCommit(message);
-
-  if (action === "y") {
-    try {
-      const result = await commit(message);
-      printCommitResult(result, message);
-    } catch (err) {
-      console.error(
-        `  ${RED}Commit failed: ${err instanceof Error ? err.message : err}${RESET}`,
-      );
-      process.exit(1);
-    }
-  } else if (action === "e") {
-    const edited = await editMessage(message);
-    if (edited) {
-      try {
-        const result = await commit(edited);
-        printCommitResult(result, edited);
-      } catch (err) {
-        console.error(
-          `  ${RED}Commit failed: ${err instanceof Error ? err.message : err}${RESET}`,
-        );
-        process.exit(1);
-      }
-    } else {
-      console.log("  Aborted.");
-    }
-  } else {
-    const copied = await copyToClipboard(message);
-    console.log(
-      copied
-        ? `  Aborted. Message copied to clipboard.`
-        : `  Aborted. Message: ${message}`,
-    );
-  }
-
-  return "done";
-}
-
-async function handlePR(draft: boolean): Promise<"done" | "back"> {
-  const config = await loadConfig();
-
-  if (!config.apiKey) {
-    console.error(
-      `  ${RED}Error: API key not set. Run ${BOLD}gai config${RESET}${RED} to configure.${RESET}`,
-    );
-    process.exit(1);
-  }
-
-  if (!(await isGitRepo())) {
-    console.error(`  ${RED}Error: Not a git repository.${RESET}`);
-    process.exit(1);
-  }
-
-  let platform = await detectPlatform();
-  if (!platform) {
-    const hostname = (await getRemoteHostname()) || "unknown";
-    const chosen = await selectPlatform(hostname);
-    if (chosen === BACK) return "back";
-    if (!chosen) {
-      console.log("  Aborted.");
-      process.exit(0);
-    }
-    platform = chosen;
-  }
-
-  const platformLabel =
-    platform === "github" ? "GitHub" : platform === "gitlab" ? "GitLab" : "Gitea";
-  console.log(`  Using: ${CYAN}${platformLabel}${RESET}`);
-
-  const baseBranch = await getDefaultBranch();
-  const branchName = await getBranchName();
-
-  if (branchName === baseBranch) {
-    console.error(
-      `  ${RED}Error: You are on the default branch (${baseBranch}). Switch to a feature branch first.${RESET}`,
-    );
-    process.exit(1);
-  }
-
-  console.log(
-    `  Branch: ${CYAN}${branchName}${RESET} → base: ${CYAN}${baseBranch}${RESET}`,
-  );
-
-  const commits = await getBranchCommits(baseBranch);
-
-  if (commits.length === 0) {
-    const choice = await selectOne({
-      title: "No commits to compare",
-      subtitle: `No commits on ${branchName} compared to ${baseBranch}. Commit something first.`,
-      items: [{ label: "Back", value: "back" as const }],
-    });
-    if (choice === null) process.exit(0);
-    return "done";
-  }
-
-  console.log(
-    `  ${commits.length} commit${commits.length > 1 ? "s" : ""} on this branch`,
-  );
-
-  const pushStatus = await getBranchPushStatus();
-  if (!pushStatus.pushed) {
-    const target = pushStatus.upstream ?? `origin/${branchName}`;
-    const answer = await ask(
-      `  Branch is not pushed to ${CYAN}${target}${RESET}. Push now? [${GREEN}Y${RESET}/n] `,
-    );
-
-    if (answer.toLowerCase() === "n") {
-      console.log("  Aborted.");
-      return "done";
-    }
-
-    console.log(`  Pushing ${CYAN}${branchName}${RESET}...`);
-    try {
-      await pushCurrentBranch(branchName, pushStatus.upstream);
-      console.log(`  ${GREEN}Pushed ${branchName}.${RESET}`);
-    } catch (err) {
-      console.error(
-        `  ${RED}Push failed: ${err instanceof Error ? err.message : err}${RESET}`,
-      );
-      process.exit(1);
-    }
-  }
-
-  const diff = await getBranchDiff(baseBranch);
-  if (!diff) {
-    console.error(`  ${RED}Error: No diff from base branch.${RESET}`);
-    process.exit(1);
-  }
-
-  const MAX_DIFF_SIZE = 15000;
-  const truncatedDiff =
-    diff.length > MAX_DIFF_SIZE
-      ? diff.substring(0, MAX_DIFF_SIZE) + "\n... (truncated)"
-      : diff;
-
-  const repoRoot = await getRepoRoot();
-  const projectCtx = await collectProjectContext(repoRoot);
-
-  const userPrompt = buildPRPrompt({
-    readme: projectCtx.readme,
-    packageDescription: projectCtx.packageDescription,
-    structure: projectCtx.structure,
-    branchName,
-    baseBranch,
-    branchCommits: commits,
-    diff: truncatedDiff,
-  });
-
-  console.log("\n  Generating PR title...");
-
-  let title: string;
-  let body: string;
-  try {
-    const result = await generatePRMessage(config, PR_SYSTEM_PROMPT, userPrompt);
-    title = result.title;
-    body = result.body;
-  } catch (err) {
-    console.error(
-      `  ${RED}AI request failed: ${err instanceof Error ? err.message : err}${RESET}`,
-    );
-    process.exit(1);
-  }
-
-  console.log(`\n  ${BOLD}Generated PR:${RESET}`);
-  console.log(`    Title: ${GREEN}${title}${RESET}`);
-  if (body) {
-    console.log(
-      `    Body:  ${DIM}${body.replace(/\n/g, "\n           ")}${RESET}`,
-    );
-  }
-  console.log("");
-
-  const answer = await ask(`  Create this PR? [${GREEN}Y${RESET}/n/e] `);
-  const lower = answer.toLowerCase();
-
-  if (lower === "n") {
-    console.log("  Aborted.");
-    return "done";
-  }
-
-  if (lower === "e") {
-    const newTitle = await ask("  Title: ");
-    const newBody = await ask("  Body (optional): ");
-    if (!newTitle.trim()) {
-      console.log("  Aborted.");
-      return "done";
-    }
-    title = newTitle;
-    body = newBody;
-  }
-
-  console.log(`\n  Creating PR...`);
-
-  try {
-    const url = await createPR(platform, title, body, baseBranch, draft);
-    console.log(`  ${GREEN}${BOLD}✔ PR created!${RESET}`);
-    console.log(`    ${CYAN}${url}${RESET}`);
-  } catch (err) {
-    console.error(
-      `  ${RED}PR creation failed: ${err instanceof Error ? err.message : err}${RESET}`,
-    );
-    process.exit(1);
-  }
-
-  return "done";
-}
-
-async function main() {
-  if (args.includes("--help") || args.includes("-h")) {
-    showHelp();
-    return;
-  }
-
-  if (args.includes("--version") || args.includes("-v")) {
-    console.log("gai v0.1.0");
-    return;
-  }
-
-  const subcommand = args[0];
-
-  if (subcommand === "config") {
-    await handleConfig();
-    return;
-  }
-
-  if (subcommand === "help") {
-    showHelp();
-    return;
-  }
-
-  if (subcommand === "commit") {
-    const autoMode = args.includes("--auto") || args.includes("-a");
-    const dryRun = args.includes("--dry-run") || args.includes("-d");
-    await handleCommit(autoMode, dryRun);
-    return;
-  }
-
-  if (subcommand === "pr") {
-    const draft = args.includes("--draft");
-    await handlePR(draft);
-    return;
-  }
-
-  if (!subcommand) {
-    await showMenu();
-    return;
-  }
-
-  console.error(`  ${RED}Unknown command: ${subcommand}${RESET}`);
-  showHelp();
-  process.exit(1);
-}
+// ── Main ───────────────────────────────────────────────────────────────
 
 process.on("SIGINT", () => {
-  process.stdout.write("\x1b[?25h");
+  process.stdout.write("\x1b[?25h"); // ensure cursor is shown
   process.stdout.write("\n");
   process.exit(130);
 });
 
-main().catch((err) => {
-  console.error(`  ${RED}Unexpected error: ${err}${RESET}`);
-  process.exit(1);
-});
+const args = process.argv.slice(2);
+
+// Initialize TTY detection early (before any command handlers run)
+initTTY();
+
+// Apply --no-color early
+if (args.includes("--no-color")) {
+  setColorEnabled(false);
+}
+
+runCLI(args, commands)
+  .then((exitCode) => {
+    process.exit(exitCode);
+  })
+  .catch((err) => {
+    console.error(`\n  Unexpected error: ${err.message ?? err}\n`);
+    process.exit(1);
+  });
diff --git a/src/clipboard.ts b/src/clipboard.ts
index b42c988..7611d41 100644
--- a/src/clipboard.ts
+++ b/src/clipboard.ts
@@ -1,26 +1,26 @@
 export async function copyToClipboard(text: string): Promise<boolean> {
-  const commands: string[][] = [];
+    const commands: string[][] = [];
 
-  if (process.platform === "darwin") {
-    commands.push(["pbcopy"]);
-  } else if (process.platform === "linux") {
-    commands.push(["xclip", "-selection", "clipboard"]);
-    commands.push(["xsel", "--clipboard", "--input"]);
-  }
+    if (process.platform === "darwin") {
+        commands.push(["pbcopy"]);
+    } else if (process.platform === "linux") {
+        commands.push(["xclip", "-selection", "clipboard"]);
+        commands.push(["xsel", "--clipboard", "--input"]);
+    }
 
-  for (const cmd of commands) {
-    try {
-      const proc = Bun.spawn(cmd, {
-        stdin: "pipe",
-        stdout: "ignore",
-        stderr: "ignore",
-      });
-      proc.stdin.write(text);
-      proc.stdin.end();
-      const exitCode = await proc.exited;
-      if (exitCode === 0) return true;
-    } catch {}
-  }
+    for (const cmd of commands) {
+        try {
+            const proc = Bun.spawn(cmd, {
+                stdin: "pipe",
+                stdout: "ignore",
+                stderr: "ignore",
+            });
+            proc.stdin.write(text);
+            proc.stdin.end();
+            const exitCode = await proc.exited;
+            if (exitCode === 0) return true;
+        } catch {}
+    }
 
-  return false;
+    return false;
 }
diff --git a/src/menu.ts b/src/menu.ts
index 4d59295..63e1d79 100644
--- a/src/menu.ts
+++ b/src/menu.ts
@@ -1,4 +1,5 @@
 import { BOLD, GREEN, CYAN, DIM, RESET } from "./terminal";
+import { isStdinTTY } from "./tty";
 
 const UP = "\x1b[A";
 const DOWN = "\x1b[B";
@@ -38,13 +39,8 @@ interface MultiPromptOptions<T> extends BasePromptOptions {
   doneLabel?: string;
 }
 
-function hideCursor() {
-  process.stdout.write("\x1b[?25l");
-}
-
-function showCursor() {
-  process.stdout.write("\x1b[?25h");
-}
+function hideCursor() { process.stdout.write("\x1b[?25l"); }
+function showCursor() { process.stdout.write("\x1b[?25h"); }
 
 function moveUp(lines: number) {
   if (lines > 0) process.stdout.write(`\x1b[${lines}A`);
@@ -65,10 +61,10 @@ function padLabel(label: string, width: number) {
 function controls(mode: "single" | "multi", showBackHint = true) {
   if (mode === "single") {
     const backHint = showBackHint ? " · ←/backspace back" : "";
-    return `${DIM}↑/↓ navigate · enter/space select${backHint} · ctrl+c cancel${RESET}`;
+    return `${DIM()}↑/↓ navigate · enter/space select${backHint} · ctrl+c cancel${RESET()}`;
   }
   const backHint = showBackHint ? " · ←/backspace back" : "";
-  return `${DIM}↑/↓ navigate · space toggle · enter confirm${backHint} · ctrl+c cancel${RESET}`;
+  return `${DIM()}↑/↓ navigate · space toggle · enter confirm${backHint} · ctrl+c cancel${RESET()}`;
 }
 
 function renderPrompt(lines: string[], previousLines: number) {
@@ -79,10 +75,7 @@ function renderPrompt(lines: string[], previousLines: number) {
     }
     moveUp(previousLines);
   }
-
-  for (const line of lines) {
-    process.stdout.write(`${line}\n`);
-  }
+  for (const line of lines) process.stdout.write(`${line}\n`);
   moveUp(lines.length);
   return lines.length;
 }
@@ -98,28 +91,19 @@ function clearPrompt(lines: number) {
 function normalizeKey(key: string, escapeBuf: string) {
   if (key === UP || key === ALT_UP) return { action: "up", escapeBuf: "" };
   if (key === DOWN || key === ALT_DOWN) return { action: "down", escapeBuf: "" };
-  if (key === LEFT || key === ALT_LEFT || key === BACKSPACE) {
-    return { action: "back", escapeBuf: "" };
-  }
+  if (key === LEFT || key === ALT_LEFT || key === BACKSPACE) return { action: "back", escapeBuf: "" };
   if (key === SPACE) return { action: "space", escapeBuf: "" };
   if (key === ENTER) return { action: "enter", escapeBuf: "" };
   if (key === CTRL_C) return { action: "cancel", escapeBuf: "" };
 
-  if (key === "\x1b" || key.startsWith("\x1b[")) {
-    return { action: null, escapeBuf: key };
-  }
+  if (key === "\x1b" || key.startsWith("\x1b[")) return { action: null, escapeBuf: key };
 
   if (escapeBuf) {
     const next = escapeBuf + key;
     if (next === UP || next === ALT_UP) return { action: "up", escapeBuf: "" };
     if (next === DOWN || next === ALT_DOWN) return { action: "down", escapeBuf: "" };
-    if (next === LEFT || next === ALT_LEFT) {
-      return { action: "back", escapeBuf: "" };
-    }
-    return {
-      action: null,
-      escapeBuf: /^[A-Za-z~]$/.test(key) || next.length > 8 ? "" : next,
-    };
+    if (next === LEFT || next === ALT_LEFT) return { action: "back", escapeBuf: "" };
+    return { action: null, escapeBuf: /^[A-Za-z~]$/.test(key) || next.length > 8 ? "" : next };
   }
 
   return { action: null, escapeBuf: "" };
@@ -130,41 +114,35 @@ function createLines<T>(
   mode: "single" | "multi",
   cursor: number,
 ) {
-  const labelWidth = Math.max(
-    ...options.items.map((item) => visibleLength(item.label)),
-    0,
-  ) + 2;
-
+  const labelWidth = Math.max(...options.items.map((item) => visibleLength(item.label)), 0) + 2;
   const lines = [
     "",
-    `  ${BOLD}${options.title}${RESET}`,
+    `  ${BOLD()}${options.title}${RESET()}`,
   ];
 
-  if (options.subtitle) lines.push(`  ${DIM}${options.subtitle}${RESET}`);
+  if (options.subtitle) lines.push(`  ${DIM()}${options.subtitle}${RESET()}`);
   lines.push(`  ${controls(mode, options.allowBack !== false)}`, "");
 
   for (let i = 0; i < options.items.length; i++) {
     const item = options.items[i]!;
     const active = i === cursor;
-    const pointer = active ? `${CYAN}❯${RESET}` : " ";
+    const pointer = active ? `${CYAN()}❯${RESET()}` : " ";
     const marker = mode === "single"
-      ? active ? `${GREEN}●${RESET}` : `${DIM}○${RESET}`
-      : item.selected ? `${GREEN}◼${RESET}` : `${DIM}□${RESET}`;
-    const label = active ? `${BOLD}${item.label}${RESET}` : item.label;
+      ? active ? `${GREEN()}●${RESET()}` : `${DIM()}○${RESET()}`
+      : item.selected ? `${GREEN()}◼${RESET()}` : `${DIM()}□${RESET()}`;
+    const label = active ? `${BOLD()}${item.label}${RESET()}` : item.label;
     const description = item.description
-      ? active ? item.description : `${DIM}${item.description}${RESET}`
+      ? active ? item.description : `${DIM()}${item.description}${RESET()}`
       : "";
 
-    lines.push(
-      `  ${pointer} ${marker} ${padLabel(label, labelWidth)}${description}`,
-    );
+    lines.push(`  ${pointer} ${marker} ${padLabel(label, labelWidth)}${description}`);
   }
 
   return lines;
 }
 
 function ensureTTY(title: string) {
-  if (process.stdin.isTTY !== true) {
+  if (!isStdinTTY()) {
     throw new Error(`${title} requires a TTY.`);
   }
 }
@@ -184,12 +162,8 @@ export async function selectOne<T>(
   hideCursor();
 
   const render = () => {
-    renderedLines = renderPrompt(
-      createLines(options, "single", cursor),
-      renderedLines,
-    );
+    renderedLines = renderPrompt(createLines(options, "single", cursor), renderedLines);
   };
-
   render();
 
   return new Promise((resolve) => {
@@ -210,16 +184,10 @@ export async function selectOne<T>(
       escapeBuf = result.escapeBuf;
 
       if (result.action === "cancel") return finish(null);
-      if (result.action === "back" && options.allowBack !== false) {
-        return finish(BACK);
-      }
-      if (result.action === "up" && cursor > 0) {
-        cursor--;
-        render();
-      } else if (result.action === "down" && cursor < options.items.length - 1) {
-        cursor++;
-        render();
-      } else if (result.action === "space" || result.action === "enter") {
+      if (result.action === "back" && options.allowBack !== false) return finish(BACK);
+      if (result.action === "up" && cursor > 0) { cursor--; render(); }
+      else if (result.action === "down" && cursor < options.items.length - 1) { cursor++; render(); }
+      else if (result.action === "space" || result.action === "enter") {
         finish(options.items[cursor]!.value);
       }
     };
@@ -257,11 +225,8 @@ export async function selectMany<T>(
   const toggle = (index: number) => {
     const item = items[index]!;
     item.selected = !item.selected;
-
     if (options.selectAllLabel && index === 0) {
-      for (let i = 1; i < items.length; i++) {
-        items[i]!.selected = item.selected;
-      }
+      for (let i = 1; i < items.length; i++) items[i]!.selected = item.selected;
     } else {
       syncSelectAll();
     }
@@ -269,19 +234,10 @@ export async function selectMany<T>(
 
   const render = () => {
     renderedLines = renderPrompt(
-      createLines(
-        {
-          title: options.title,
-          subtitle: options.subtitle,
-          items,
-        },
-        "multi",
-        cursor,
-      ),
+      createLines({ title: options.title, subtitle: options.subtitle, items }, "multi", cursor),
       renderedLines,
     );
   };
-
   render();
 
   return new Promise((resolve) => {
@@ -302,24 +258,12 @@ export async function selectMany<T>(
       escapeBuf = result.escapeBuf;
 
       if (result.action === "cancel") return finish(null);
-      if (result.action === "back" && options.allowBack !== false) {
-        return finish(BACK);
-      }
-      if (result.action === "up" && cursor > 0) {
-        cursor--;
-        render();
-      } else if (result.action === "down" && cursor < items.length - 1) {
-        cursor++;
-        render();
-      } else if (result.action === "space") {
-        toggle(cursor);
-        render();
-      } else if (result.action === "enter") {
-        finish(
-          items
-            .filter((item) => item.selected && item.value !== null)
-            .map((item) => item.value as T),
-        );
+      if (result.action === "back" && options.allowBack !== false) return finish(BACK);
+      if (result.action === "up" && cursor > 0) { cursor--; render(); }
+      else if (result.action === "down" && cursor < items.length - 1) { cursor++; render(); }
+      else if (result.action === "space") { toggle(cursor); render(); }
+      else if (result.action === "enter") {
+        finish(items.filter((item) => item.selected && item.value !== null).map((item) => item.value as T));
       }
     };
 
diff --git a/src/selector.ts b/src/selector.ts
index 96019b1..2672130 100644
--- a/src/selector.ts
+++ b/src/selector.ts
@@ -1,5 +1,6 @@
 import type { FileEntry } from "./types";
 import { BOLD, GREEN, YELLOW, RESET } from "./terminal";
+import { isStdinTTY } from "./tty";
 import { BACK, selectMany } from "./menu";
 import type { PromptBack } from "./menu";
 
@@ -10,13 +11,13 @@ export async function selectFiles(
   if (unstagedFiles.length === 0) return [];
 
   if (stagedFiles.length > 0) {
-    process.stdout.write(`\n  ${BOLD}Staged files (will be included):${RESET}\n`);
+    process.stdout.write(`\n  ${BOLD()}Staged files (will be included):${RESET()}\n`);
     for (const f of stagedFiles) {
-      process.stdout.write(`    ${GREEN}✓${RESET} ${f.path} (${YELLOW}${f.label}${RESET})\n`);
+      process.stdout.write(`    ${GREEN()}✓${RESET()} ${f.path} (${YELLOW()}${f.label}${RESET()})\n`);
     }
   }
 
-  if (process.stdin.isTTY !== true) return [];
+  if (!isStdinTTY()) return [];
 
   const selected = await selectMany({
     title: "Select files to stage",
@@ -35,7 +36,7 @@ export async function selectFiles(
 
   if (selected.length > 0) {
     process.stdout.write(
-      `  ${GREEN}Staged ${selected.length} file(s):${RESET} ${selected.join(", ")}\n`,
+      `  ${GREEN()}Staged ${selected.length} file(s):${RESET()} ${selected.join(", ")}\n`,
     );
   }