feat: activate buddy system in open build (#346)

scripts/build.ts

@@ -3,7 +3,7 @@
  * distributable JS file using Bun's bundler.
  *
  * Handles:
- * - bun:bundle feature() flags → all false (disables internal-only features)
+ * - bun:bundle feature() flags for the open build
  * - MACRO.* globals → inlined version/build-time constants
  * - src/ path aliases
  */
@@ -14,8 +14,9 @@ import { noTelemetryPlugin } from './no-telemetry-plugin'
 const pkg = JSON.parse(readFileSync('./package.json', 'utf-8'))
 const version = pkg.version
 
-// Feature flags — all disabled for the open build.
-// These gate Anthropic-internal features (voice, proactive, kairos, etc.)
+// Feature flags for the open build.
+// Most Anthropic-internal features stay off; open-build features can be
+// selectively enabled here when their full source exists in the mirror.
 const featureFlags: Record<string, boolean> = {
   VOICE_MODE: false,
   PROACTIVE: false,
@@ -37,7 +38,7 @@ const featureFlags: Record<string, boolean> = {
   TRANSCRIPT_CLASSIFIER: false,
   WEB_BROWSER_TOOL: false,
   MESSAGE_ACTIONS: false,
-  BUDDY: false,
+  BUDDY: true,
   CHICAGO_MCP: false,
   COWORKER_TYPE_TELEMETRY: false,
 }
@@ -110,7 +111,7 @@ export async function handleBgFlag() { throw new Error("Background sessions are
         build.onLoad(
           { filter: /.*/, namespace: 'bun-bundle-shim' },
           () => ({
-            contents: `export function feature(name) { return false; }`,
+            contents: `const featureFlags = ${JSON.stringify(featureFlags)};\nexport function feature(name) { return featureFlags[name] ?? false; }`,
             loader: 'js',
           }),
         )

src/buddy/CompanionSprite.tsx

@@ -1,5 +1,4 @@
 import { c as _c } from "react-compiler-runtime";
-import { feature } from 'bun:bundle';
 import figures from 'figures';
 import React, { useEffect, useRef, useState } from 'react';
 import { useTerminalSize } from '../hooks/useTerminalSize.js';
@@ -11,6 +10,7 @@ import { getGlobalConfig } from '../utils/config.js';
 import { isFullscreenActive } from '../utils/fullscreen.js';
 import type { Theme } from '../utils/theme.js';
 import { getCompanion } from './companion.js';
+import { isBuddyEnabled } from './feature.js';
 import { renderFace, renderSprite, spriteFrameCount } from './sprites.js';
 import { RARITY_COLORS } from './types.js';
 const TICK_MS = 500;
@@ -165,7 +165,7 @@ function spriteColWidth(nameWidth: number): number {
 // Narrow terminals: 0 — REPL.tsx stacks the one-liner on its own row
 // (above input in fullscreen, below in scrollback), so no reservation.
 export function companionReservedColumns(terminalColumns: number, speaking: boolean): number {
-  if (!feature('BUDDY')) return 0;
+  if (!isBuddyEnabled()) return 0;
   const companion = getCompanion();
   if (!companion || getGlobalConfig().companionMuted) return 0;
   if (terminalColumns < MIN_COLS_FOR_FULL_SPRITE) return 0;
@@ -212,7 +212,7 @@ export function CompanionSprite(): React.ReactNode {
     return () => clearTimeout(timer);
     // eslint-disable-next-line react-hooks/exhaustive-deps -- tick intentionally captured at reaction-change, not tracked
   }, [reaction, setAppState]);
-  if (!feature('BUDDY')) return null;
+  if (!isBuddyEnabled()) return null;
   const companion = getCompanion();
   if (!companion || getGlobalConfig().companionMuted) return null;
   const color = RARITY_COLORS[companion.rarity];
@@ -337,7 +337,7 @@ export function CompanionFloatingBubble() {
     t3 = $[4];
   }
   useEffect(t2, t3);
-  if (!feature("BUDDY") || !reaction) {
+  if (!isBuddyEnabled() || !reaction) {
     return null;
   }
   const companion = getCompanion();

src/buddy/feature.ts

@@ -0,0 +1,3 @@
+export function isBuddyEnabled(): boolean {
+  return true
+}

src/buddy/observer.ts

@@ -0,0 +1,65 @@
+import type { Message } from '../types/message.js'
+import { getGlobalConfig } from '../utils/config.js'
+import { getUserMessageText } from '../utils/messages.js'
+import { getCompanion } from './companion.js'
+
+const DIRECT_REPLIES = [
+  'I am observing.',
+  'I am helping from the corner.',
+  'I saw that.',
+  'Still here.',
+  'Watching closely.',
+] as const
+
+const PET_REPLIES = [
+  'happy chirp',
+  'tiny victory dance',
+  'quietly approves',
+  'wiggles with joy',
+  'looks pleased',
+] as const
+
+function hashString(s: string): number {
+  let h = 2166136261
+  for (let i = 0; i < s.length; i++) {
+    h ^= s.charCodeAt(i)
+    h = Math.imul(h, 16777619)
+  }
+  return h >>> 0
+}
+
+function pickDeterministic<T>(items: readonly T[], seed: string): T {
+  return items[hashString(seed) % items.length]!
+}
+
+export async function fireCompanionObserver(
+  messages: Message[],
+  onReaction: (reaction: string | undefined) => void,
+): Promise<void> {
+  const companion = getCompanion()
+  if (!companion || getGlobalConfig().companionMuted) return
+
+  const lastUser = [...messages].reverse().find(msg => msg.type === 'user')
+  if (!lastUser) return
+
+  const text = getUserMessageText(lastUser)?.trim()
+  if (!text) return
+
+  const lower = text.toLowerCase()
+  const companionName = companion.name.toLowerCase()
+
+  if (lower.includes('/buddy')) {
+    onReaction(pickDeterministic(PET_REPLIES, text + companion.name))
+    return
+  }
+
+  if (
+    lower.includes(companionName) ||
+    lower.includes('buddy') ||
+    lower.includes('companion')
+  ) {
+    onReaction(
+      `${companion.name}: ${pickDeterministic(DIRECT_REPLIES, text + companion.personality)}`,
+    )
+  }
+}

src/buddy/prompt.ts

@@ -1,8 +1,8 @@
-import { feature } from 'bun:bundle'
 import type { Message } from '../types/message.js'
 import type { Attachment } from '../utils/attachments.js'
 import { getGlobalConfig } from '../utils/config.js'
 import { getCompanion } from './companion.js'
+import { isBuddyEnabled } from './feature.js'
 
 export function companionIntroText(name: string, species: string): string {
   return `# Companion
@@ -15,7 +15,7 @@ When the user addresses ${name} directly (by name), its bubble will answer. Your
 export function getCompanionIntroAttachment(
   messages: Message[] | undefined,
 ): Attachment[] {
-  if (!feature('BUDDY')) return []
+  if (!isBuddyEnabled()) return []
   const companion = getCompanion()
   if (!companion || getGlobalConfig().companionMuted) return []
 

src/buddy/useBuddyNotification.tsx

@@ -1,10 +1,10 @@
 import { c as _c } from "react-compiler-runtime";
-import { feature } from 'bun:bundle';
 import React, { useEffect } from 'react';
 import { useNotifications } from '../context/notifications.js';
 import { Text } from '../ink.js';
 import { getGlobalConfig } from '../utils/config.js';
 import { getRainbowColor } from '../utils/thinking.js';
+import { isBuddyEnabled } from './feature.js';
 
 // Local date, not UTC — 24h rolling wave across timezones. Sustained Twitter
 // buzz instead of a single UTC-midnight spike, gentler on soul-gen load.
@@ -50,7 +50,7 @@ export function useBuddyNotification() {
   let t1;
   if ($[0] !== addNotification || $[1] !== removeNotification) {
     t0 = () => {
-      if (!feature("BUDDY")) {
+      if (!isBuddyEnabled()) {
         return;
       }
       const config = getGlobalConfig();
@@ -80,7 +80,7 @@ export function findBuddyTriggerPositions(text: string): Array<{
   start: number;
   end: number;
 }> {
-  if (!feature('BUDDY')) return [];
+  if (!isBuddyEnabled()) return [];
   const triggers: Array<{
     start: number;
     end: number;

src/commands.ts

@@ -59,6 +59,7 @@ import usage from './commands/usage/index.js'
 import theme from './commands/theme/index.js'
 import vim from './commands/vim/index.js'
 import { feature } from 'bun:bundle'
+import { isBuddyEnabled } from './buddy/feature.js'
 // Dead code elimination: conditional imports
 /* eslint-disable @typescript-eslint/no-require-imports */
 const proactive =
@@ -117,7 +118,7 @@ const forkCmd = feature('FORK_SUBAGENT')
       require('./commands/fork/index.js') as typeof import('./commands/fork/index.js')
     ).default
   : null
-const buddy = feature('BUDDY')
+const buddy = isBuddyEnabled()
   ? (
       require('./commands/buddy/index.js') as typeof import('./commands/buddy/index.js')
     ).default

src/commands/buddy/buddy.tsx

@@ -0,0 +1,185 @@
+import type { LocalJSXCommandContext, LocalJSXCommandOnDone } from '../../types/command.js'
+import { getGlobalConfig, saveGlobalConfig } from '../../utils/config.js'
+import { companionUserId, getCompanion, rollWithSeed } from '../../buddy/companion.js'
+import type { StoredCompanion } from '../../buddy/types.js'
+import { COMMON_HELP_ARGS, COMMON_INFO_ARGS } from '../../constants/xml.js'
+
+const NAME_PREFIXES = [
+  'Byte',
+  'Echo',
+  'Glint',
+  'Miso',
+  'Nova',
+  'Pixel',
+  'Rune',
+  'Static',
+  'Vector',
+  'Whisk',
+] as const
+
+const NAME_SUFFIXES = [
+  'bean',
+  'bit',
+  'bud',
+  'dot',
+  'ling',
+  'loop',
+  'moss',
+  'patch',
+  'puff',
+  'spark',
+] as const
+
+const PERSONALITIES = [
+  'Curious and quietly encouraging',
+  'A patient little watcher with strong debugging instincts',
+  'Playful, observant, and suspicious of flaky tests',
+  'Calm under pressure and fond of clean diffs',
+  'A tiny terminal gremlin who likes successful builds',
+] as const
+
+const PET_REACTIONS = [
+  'leans into the headpat',
+  'does a proud little bounce',
+  'emits a content beep',
+  'looks delighted',
+  'wiggles happily',
+] as const
+
+function hashString(s: string): number {
+  let h = 2166136261
+  for (let i = 0; i < s.length; i++) {
+    h ^= s.charCodeAt(i)
+    h = Math.imul(h, 16777619)
+  }
+  return h >>> 0
+}
+
+function pickDeterministic<T>(items: readonly T[], seed: string): T {
+  return items[hashString(seed) % items.length]!
+}
+
+function titleCase(s: string): string {
+  return s.charAt(0).toUpperCase() + s.slice(1)
+}
+
+function createStoredCompanion(): StoredCompanion {
+  const userId = companionUserId()
+  const { bones } = rollWithSeed(`${userId}:buddy`)
+  const prefix = pickDeterministic(NAME_PREFIXES, `${userId}:prefix`)
+  const suffix = pickDeterministic(NAME_SUFFIXES, `${userId}:suffix`)
+  const personality = pickDeterministic(PERSONALITIES, `${userId}:personality`)
+
+  return {
+    name: `${prefix}${suffix}`,
+    personality: `${personality}.`,
+    hatchedAt: Date.now(),
+  }
+}
+
+function setCompanionReaction(
+  context: LocalJSXCommandContext,
+  reaction: string | undefined,
+  pet = false,
+): void {
+  context.setAppState(prev => ({
+    ...prev,
+    companionReaction: reaction,
+    companionPetAt: pet ? Date.now() : prev.companionPetAt,
+  }))
+}
+
+function showHelp(onDone: LocalJSXCommandOnDone): void {
+  onDone(
+    'Usage: /buddy [status|mute|unmute]\n\nRun /buddy with no args to hatch your companion the first time, then pet it on later runs.',
+    { display: 'system' },
+  )
+}
+
+export async function call(
+  onDone: LocalJSXCommandOnDone,
+  context: LocalJSXCommandContext,
+  args?: string,
+): Promise<null> {
+  const arg = args?.trim().toLowerCase() ?? ''
+
+  if (COMMON_HELP_ARGS.includes(arg) || arg === '') {
+    const existing = getCompanion()
+    if (arg !== '' || existing) {
+      if (arg !== '') {
+        showHelp(onDone)
+        return null
+      }
+    }
+  }
+
+  if (COMMON_HELP_ARGS.includes(arg)) {
+    showHelp(onDone)
+    return null
+  }
+
+  if (COMMON_INFO_ARGS.includes(arg) || arg === 'status') {
+    const companion = getCompanion()
+    if (!companion) {
+      onDone('No buddy hatched yet. Run /buddy to hatch one.', {
+        display: 'system',
+      })
+      return null
+    }
+    onDone(
+      `${companion.name} is your ${titleCase(companion.rarity)} ${companion.species}. ${companion.personality}`,
+      { display: 'system' },
+    )
+    return null
+  }
+
+  if (arg === 'mute' || arg === 'unmute') {
+    const muted = arg === 'mute'
+    saveGlobalConfig(current => ({
+      ...current,
+      companionMuted: muted,
+    }))
+    if (muted) {
+      setCompanionReaction(context, undefined)
+    }
+    onDone(`Buddy ${muted ? 'muted' : 'unmuted'}.`, { display: 'system' })
+    return null
+  }
+
+  if (arg !== '') {
+    showHelp(onDone)
+    return null
+  }
+
+  let companion = getCompanion()
+  if (!companion) {
+    const stored = createStoredCompanion()
+    saveGlobalConfig(current => ({
+      ...current,
+      companion: stored,
+      companionMuted: false,
+    }))
+    companion = {
+      ...rollWithSeed(`${companionUserId()}:buddy`).bones,
+      ...stored,
+    }
+    setCompanionReaction(
+      context,
+      `${companion.name} the ${companion.species} has hatched.`,
+      true,
+    )
+    onDone(
+      `${companion.name} the ${companion.species} is now your buddy. Run /buddy again to pet them.`,
+      { display: 'system' },
+    )
+    return null
+  }
+
+  const reaction = `${companion.name} ${pickDeterministic(
+    PET_REACTIONS,
+    `${Date.now()}:${companion.name}`,
+  )}`
+  setCompanionReaction(context, reaction, true)
+  onDone(undefined, { display: 'skip' })
+  return null
+}

src/commands/buddy/index.ts

@@ -0,0 +1,12 @@
+import type { Command } from '../../commands.js'
+
+const buddy = {
+  type: 'local-jsx',
+  name: 'buddy',
+  description: 'Hatch, pet, and manage your Open Claude companion',
+  immediate: true,
+  argumentHint: '[status|mute|unmute|help]',
+  load: () => import('./buddy.js'),
+} satisfies Command
+
+export default buddy

src/components/PromptInput/PromptInput.tsx

@@ -13,6 +13,7 @@ import { getCwd } from 'src/utils/cwd.js';
 import { isQueuedCommandEditable, popAllEditable } from 'src/utils/messageQueueManager.js';
 import stripAnsi from 'strip-ansi';
 import { companionReservedColumns } from '../../buddy/CompanionSprite.js';
+import { isBuddyEnabled } from '../../buddy/feature.js';
 import { findBuddyTriggerPositions, useBuddyNotification } from '../../buddy/useBuddyNotification.js';
 import { FastModePicker } from '../../commands/fast/fast.js';
 import { isUltrareviewEnabled } from '../../commands/review/ultrareviewEnabled.js';
@@ -309,7 +310,7 @@ function PromptInput({
   const {
     companion: _companion,
     companionMuted
-  } = feature('BUDDY') ? getGlobalConfig() : {
+  } = isBuddyEnabled() ? getGlobalConfig() : {
     companion: undefined,
     companionMuted: undefined
   };
@@ -1786,7 +1787,7 @@ function PromptInput({
       }
       switch (footerItemSelected) {
         case 'companion':
-          if (feature('BUDDY')) {
+          if (isBuddyEnabled()) {
             selectFooterItem(null);
             void onSubmit('/buddy');
           }
@@ -1981,8 +1982,7 @@ function PromptInput({
     });
   }, [effortNotificationText, addNotification, removeNotification]);
   useBuddyNotification();
-  const companionSpeaking = feature('BUDDY') ?
-  // biome-ignore lint/correctness/useHookAtTopLevel: feature() is a compile-time constant
+  const companionSpeaking = isBuddyEnabled() ?
   useAppState(s => s.companionReaction !== undefined) : false;
   const {
     columns,

src/screens/REPL.tsx

@@ -275,6 +275,8 @@ const WebBrowserPanelModule = feature('WEB_BROWSER_TOOL') ? require('../tools/We
 import { IssueFlagBanner } from '../components/PromptInput/IssueFlagBanner.js';
 import { useIssueFlagBanner } from '../hooks/useIssueFlagBanner.js';
 import { CompanionSprite, CompanionFloatingBubble, MIN_COLS_FOR_FULL_SPRITE } from '../buddy/CompanionSprite.js';
+import { isBuddyEnabled } from '../buddy/feature.js';
+import { fireCompanionObserver } from '../buddy/observer.js';
 import { DevBar } from '../components/DevBar.js';
 // Session manager removed - using AppState now
 import type { RemoteSessionConfig } from '../remote/RemoteSessionManager.js';
@@ -1302,7 +1304,7 @@ export function REPL({
       // Dismiss the companion bubble on scroll — it's absolute-positioned
       // at bottom-right and covers transcript content. Scrolling = user is
       // trying to read something under it.
-      if (feature('BUDDY')) {
+      if (isBuddyEnabled()) {
         setAppState(prev => prev.companionReaction === undefined ? prev : {
           ...prev,
           companionReaction: undefined
@@ -2806,7 +2808,7 @@ export function REPL({
     })) {
       onQueryEvent(event);
     }
-    if (feature('BUDDY')) {
+    if (isBuddyEnabled()) {
       void fireCompanionObserver(messagesRef.current, reaction => setAppState(prev => prev.companionReaction === reaction ? prev : {
         ...prev,
         companionReaction: reaction
@@ -4567,7 +4569,7 @@ export function REPL({
     {feature('MESSAGE_ACTIONS') && isFullscreenEnvEnabled() && !disableMessageActions ? <MessageActionsKeybindings handlers={messageActionHandlers} isActive={cursor !== null} /> : null}
     <CancelRequestHandler {...cancelRequestProps} />
     <MCPConnectionManager key={remountKey} dynamicMcpConfig={dynamicMcpConfig} isStrictMcpConfig={strictMcpConfig}>
-      <FullscreenLayout scrollRef={scrollRef} overlay={toolPermissionOverlay} bottomFloat={feature('BUDDY') && companionVisible && !companionNarrow ? <CompanionFloatingBubble /> : undefined} modal={centeredModal} modalScrollRef={modalScrollRef} dividerYRef={dividerYRef} hidePill={!!viewedAgentTask} hideSticky={!!viewedTeammateTask} newMessageCount={unseenDivider?.count ?? 0} onPillClick={() => {
+      <FullscreenLayout scrollRef={scrollRef} overlay={toolPermissionOverlay} bottomFloat={isBuddyEnabled() && companionVisible && !companionNarrow ? <CompanionFloatingBubble /> : undefined} modal={centeredModal} modalScrollRef={modalScrollRef} dividerYRef={dividerYRef} hidePill={!!viewedAgentTask} hideSticky={!!viewedTeammateTask} newMessageCount={unseenDivider?.count ?? 0} onPillClick={() => {
         setCursor(null);
         jumpToNew(scrollRef.current);
       }} scrollable={<>
@@ -4592,8 +4594,8 @@ export function REPL({
         {showSpinner && <SpinnerWithVerb mode={streamMode} spinnerTip={spinnerTip} responseLengthRef={responseLengthRef} apiMetricsRef={apiMetricsRef} overrideMessage={spinnerMessage} spinnerSuffix={stopHookSpinnerSuffix} verbose={verbose} loadingStartTimeRef={loadingStartTimeRef} totalPausedMsRef={totalPausedMsRef} pauseStartTimeRef={pauseStartTimeRef} overrideColor={spinnerColor} overrideShimmerColor={spinnerShimmerColor} hasActiveTools={inProgressToolUseIDs.size > 0} leaderIsIdle={!isLoading} />}
         {!showSpinner && !isLoading && !userInputOnProcessing && !hasRunningTeammates && isBriefOnly && !viewedAgentTask && <BriefIdleStatus />}
         {isFullscreenEnvEnabled() && <PromptInputQueuedCommands />}
-      </>} bottom={<Box flexDirection={feature('BUDDY') && companionNarrow ? 'column' : 'row'} width="100%" alignItems={feature('BUDDY') && companionNarrow ? undefined : 'flex-end'}>
-        {feature('BUDDY') && companionNarrow && isFullscreenEnvEnabled() && companionVisible ? <CompanionSprite /> : null}
+      </>} bottom={<Box flexDirection={isBuddyEnabled() && companionNarrow ? 'column' : 'row'} width="100%" alignItems={isBuddyEnabled() && companionNarrow ? undefined : 'flex-end'}>
+        {isBuddyEnabled() && companionNarrow && isFullscreenEnvEnabled() && companionVisible ? <CompanionSprite /> : null}
         <Box flexDirection="column" flexGrow={1}>
           {permissionStickyFooter}
           {/* Immediate local-jsx commands (/btw, /sandbox, /assistant,
@@ -4997,7 +4999,7 @@ export function REPL({
           }} />}
           {"external" === 'ant' && <DevBar />}
         </Box>
-        {feature('BUDDY') && !(companionNarrow && isFullscreenEnvEnabled()) && companionVisible ? <CompanionSprite /> : null}
+        {isBuddyEnabled() && !(companionNarrow && isFullscreenEnvEnabled()) && companionVisible ? <CompanionSprite /> : null}
       </Box>} />
     </MCPConnectionManager>
   </KeybindingSetup>;

src/utils/attachments.ts

@@ -250,6 +250,7 @@ import { isInProcessTeammate } from './teammateContext.js'
 import { removeTeammateFromTeamFile } from './swarm/teamHelpers.js'
 import { unassignTeammateTasks } from './tasks.js'
 import { getCompanionIntroAttachment } from '../buddy/prompt.js'
+import { isBuddyEnabled } from '../buddy/feature.js'
 
 export const TODO_REMINDER_CONFIG = {
   TURNS_SINCE_WRITE: 10,
@@ -861,7 +862,7 @@ export async function getAttachments(
         ),
       ),
     ),
-    ...(feature('BUDDY')
+    ...(isBuddyEnabled()
         ? [
             maybe('companion_intro', () =>
               Promise.resolve(getCompanionIntroAttachment(messages)),