diff --git a/plugins/cockpit/hooks/companion/affinity.ts b/plugins/cockpit/hooks/companion/affinity.ts
new file mode 100644
index 0000000..4f741af
--- /dev/null
+++ b/plugins/cockpit/hooks/companion/affinity.ts
@@ -0,0 +1,49 @@
+import { clamp } from './mood'
+import type { Affinity } from './types'
+
+const DAY = 86_400_000
+
+export const GAIN = 0.01
+export const DAILY_CAP = 0.05
+export const LOSS = 0.03
+const IDLE_GRACE_DAYS = 7
+const IDLE_HALF_LIFE_DAYS = 30
+
+// 升階門檻；降階門檻 = 升階門檻 − 0.05，形成遲滯
+export const UP = [0.3, 0.55, 0.8]
+export const HYSTERESIS = 0.05
+
+export const dayKey = (ms: number) => new Date(ms).toISOString().slice(0, 10)
+
+export const initialAffinity = (now: number): Affinity => ({ value: 0, stage: 0, dayKey: dayKey(now), dayGain: 0, lastSeen: now })
+
+export function stageFor(value: number, current: number): number {
+  let s = current
+  while (s < UP.length && value >= UP[s]!) s++
+  while (s > 0 && value < UP[s - 1]! - HYSTERESIS) s--
+  return s
+}
+
+// 離開超過 7 天後，以 30 天半衰期回到 0
+export function idleDecay(a: Affinity, now: number): Affinity {
+  const idleDays = (now - a.lastSeen) / DAY
+  if (idleDays <= IDLE_GRACE_DAYS) return a
+  const value = a.value * Math.pow(0.5, (idleDays - IDLE_GRACE_DAYS) / IDLE_HALF_LIFE_DAYS)
+  return { ...a, value, stage: stageFor(value, a.stage) }
+}
+
+export function interact(prev: Affinity, kind: 'meaningful' | 'negative', now: number): Affinity {
+  let a = idleDecay(prev, now)
+  const key = dayKey(now)
+  if (a.dayKey !== key) a = { ...a, dayKey: key, dayGain: 0 }
+  let { value, dayGain } = a
+  if (kind === 'meaningful') {
+    const gain = Math.max(0, Math.min(GAIN, DAILY_CAP - dayGain))
+    value += gain
+    dayGain += gain
+  } else {
+    value -= LOSS
+  }
+  value = clamp(value)
+  return { value, dayGain, dayKey: key, lastSeen: now, stage: stageFor(value, a.stage) }
+}
diff --git a/plugins/cockpit/hooks/companion/band.test.ts b/plugins/cockpit/hooks/companion/band.test.ts
new file mode 100644
index 0000000..6d7f89a
--- /dev/null
+++ b/plugins/cockpit/hooks/companion/band.test.ts
@@ -0,0 +1,74 @@
+import { describe, expect, test } from 'claude-code/testing'
+
+import { bandLines, fit, lineWidth } from '../hud/format'
+import type { HudData } from '../hud/format'
+import { fitCompanion } from './band'
+import type { View } from './core'
+
+const DATA: HudData = {
+  model: 'claude-opus-5-5[1m]',
+  cwd: '/home/dev/work/luopan',
+  home: '/home/dev',
+  git: { branch: 'issue-3', dirty: 1, ahead: 0, behind: 0 },
+  usage: { fiveHour: { percent: 42 }, sevenDay: { percent: 71 }, ctxPercent: 31 },
+  sys: { cpu: 23 },
+  tzOffsetMin: 480,
+}
+
+const VIEW: View = {
+  core: { id: 'miko', name: '月見ミコ', facts: {} as never, neuroticism: 50, baseline: { p: 0, a: 0, d: 0 } },
+  mood: { p: 0.5, a: 0, d: -0.5 },
+  label: '放鬆',
+  kaomoji: '(´ᴗ`)',
+  affinity: 0.35,
+  stage: '熟悉',
+  todos: 2,
+}
+
+const text = (v: View, cols: number, compact = false, bubble?: string) => fitCompanion(v, cols, compact, bubble).map(s => s.text).join('')
+
+describe('角色行', () => {
+  test('寬版顯示顏文字、名字、心情、PAD 條、階段、待辦、氣泡', () => {
+    expect(text(VIEW, 200, false, '早安')).toBe('(´ᴗ`) 月見ミコ 放鬆 · P▰▰▱ A▰▰▱ D▰▱▱ · 熟悉 · ☐2 · 💬 早安')
+  })
+
+  test('緊湊模式只剩「顏文字 名字 心情」', () => {
+    expect(text(VIEW, 200, true)).toBe('(´ᴗ`) 月見ミコ 放鬆')
+  })
+
+  test('寬度不足時依序捨棄氣泡、待辦、PAD、階段，不換行', () => {
+    const full = text(VIEW, 200, false, '早安')
+    let prev = full.length
+    for (const cols of [60, 50, 40, 34, 28, 22]) {
+      const t = text(VIEW, cols, false, '早安')
+      expect(t.includes('\n')).toBe(false)
+      expect(t.length <= prev).toBe(true)
+      prev = t.length
+    }
+    expect(text(VIEW, 40, false, '早安')).not.toContain('早安')
+    expect(text(VIEW, 36, false, '早安')).not.toContain('☐')
+    expect(text(VIEW, 30, false, '早安')).not.toContain('PAD')
+    expect(text(VIEW, 22, false, '早安')).toBe('(´ᴗ`) 月見ミコ 放鬆')
+    expect(lineWidth(fitCompanion(VIEW, 24))).toBeLessThanOrEqual(24)
+  })
+
+  test('沒有待辦時不顯示待辦數', () => {
+    expect(text({ ...VIEW, todos: 0 }, 200)).not.toContain('☐')
+  })
+})
+
+describe('band', () => {
+  test('沒有角色時只有第一行，且與現況逐字相同', () => {
+    for (const cols of [200, 100, 60]) {
+      const lines = bandLines(DATA, cols, false, null)
+      expect(lines.length).toBe(1)
+      expect(lines[0]).toEqual(fit(DATA, cols, false))
+    }
+  })
+
+  test('有角色時第一行不變，第二行是角色行', () => {
+    const lines = bandLines(DATA, 120, false, fitCompanion(VIEW, 120))
+    expect(lines.length).toBe(2)
+    expect(lines[0]).toEqual(fit(DATA, 120, false))
+  })
+})
diff --git a/plugins/cockpit/hooks/companion/band.ts b/plugins/cockpit/hooks/companion/band.ts
new file mode 100644
index 0000000..07a5efa
--- /dev/null
+++ b/plugins/cockpit/hooks/companion/band.ts
@@ -0,0 +1,33 @@
+import { bar, lineWidth } from '../hud/format'
+import type { Seg } from '../hud/format'
+import type { View } from './core'
+
+const axis = (v: number) => bar(((v + 1) / 2) * 100, 3)
+
+// 由完整版往下捨棄次要資訊：氣泡 → 待辦 → PAD 條 → 好感階段；緊湊版只留「顏文字 名字 心情」
+function line(v: View, level: number, compact: boolean, bubble?: string): Seg[] {
+  const out: Seg[] = [
+    { text: `${v.kaomoji} `, color: 'claude' },
+    { text: v.core.name, bold: true },
+    { text: ' ' },
+    { text: v.label, color: 'suggestion' },
+  ]
+  if (compact) return out
+  const dot = { text: ' · ', dim: true }
+  if (level < 3) out.push(dot, { text: `P${axis(v.mood.p)} A${axis(v.mood.a)} D${axis(v.mood.d)}`, dim: true })
+  if (level < 4) out.push(dot, { text: v.stage })
+  if (level < 2 && v.todos > 0) out.push(dot, { text: `☐${v.todos}`, color: 'warning' })
+  if (level < 1 && bubble) out.push(dot, { text: `💬 ${bubble}`, dim: true })
+  return out
+}
+
+export const COMPANION_MAX_LEVEL = 4
+
+export function fitCompanion(v: View, columns: number, compact = false, bubble?: string): Seg[] {
+  if (compact) return line(v, 0, true)
+  for (let level = 0; level <= COMPANION_MAX_LEVEL; level++) {
+    const l = line(v, level, false, bubble)
+    if (lineWidth(l) <= columns) return l
+  }
+  return line(v, 0, true)
+}
diff --git a/plugins/cockpit/hooks/companion/companion.test.ts b/plugins/cockpit/hooks/companion/companion.test.ts
new file mode 100644
index 0000000..274b4f3
--- /dev/null
+++ b/plugins/cockpit/hooks/companion/companion.test.ts
@@ -0,0 +1,217 @@
+import { describe, expect, test } from 'claude-code/testing'
+
+import { createCompanion } from './core'
+import { fakeClock, memoryFs } from './fs'
+import type { CompanionCore } from './types'
+
+// 測試用原創範例角色，不依賴網路或受版權保護的資料
+const MIKO: CompanionCore = {
+  id: 'miko',
+  name: '月見ミコ',
+  facts: {
+    birthday: { value: '3/3', source: 'test', kind: 'novel', confidence: 1 },
+    zodiac: 'unknown',
+    bloodType: 'unknown',
+    hair: 'unknown',
+    face: 'unknown',
+    height: 'unknown',
+    weight: 'unknown',
+    measurements: 'unknown',
+  },
+  neuroticism: 50,
+  baseline: { p: 0, a: 0, d: 0 },
+}
+const H = 3_600_000
+const DAY = 24 * H
+const ROOT = '/h/.cockpit'
+
+function setup(builtins = [MIKO]) {
+  const fs = memoryFs()
+  const clock = fakeClock()
+  return { fs, clock, c: createCompanion({ fs, clock, root: ROOT, builtins }) }
+}
+
+describe('啟用', () => {
+  test('第一次啟用自動啟用預設角色，之後不再', async () => {
+    const { c } = setup()
+    expect((await c.ensureActivated()).first).toBe(true)
+    expect((await c.view())?.core.name).toBe('月見ミコ')
+    expect((await c.ensureActivated()).first).toBe(false)
+  })
+
+  test('companion off 後沒有角色，且重新啟動不會自動再啟用', async () => {
+    const { c } = setup()
+    await c.ensureActivated()
+    await c.command('companion off')
+    expect(await c.view()).toBe(null)
+    await c.ensureActivated()
+    expect(await c.view()).toBe(null)
+    expect(await c.command('status')).toBe('目前沒有啟用角色。')
+  })
+
+  test('切換角色保留原角色資料', async () => {
+    const other = { ...MIKO, id: 'ren', name: '蓮' }
+    const { c } = setup([MIKO, other])
+    await c.ensureActivated()
+    await c.moodEvent('thanks')
+    const before = (await c.view())!.mood
+    expect(await c.command('switch ren')).toContain('蓮')
+    expect((await c.view())?.core.id).toBe('ren')
+    await c.command('switch miko')
+    expect((await c.view())!.mood).toEqual(before)
+    expect(await c.command('switch nobody')).toContain('找不到')
+  })
+})
+
+describe('原子寫入', () => {
+  test('不留暫存檔', async () => {
+    const { c, fs } = setup()
+    await c.ensureActivated()
+    await c.moodEvent('thanks')
+    expect([...fs.files.keys()].some(k => k.endsWith('.tmp'))).toBe(false)
+  })
+
+  test('寫到一半當機時舊資料不損毀', async () => {
+    const { c, fs } = setup()
+    await c.ensureActivated()
+    const path = `${ROOT}/companions/miko/state.json`
+    const old = fs.files.get(path)
+    const real = fs.rename
+    fs.rename = async () => {
+      throw new Error('crash')
+    }
+    await expect(c.moodEvent('thanks')).rejects.toThrow()
+    fs.rename = real
+    expect(fs.files.get(path)).toBe(old)
+  })
+})
+
+describe('心情', () => {
+  test('事件更新 PAD 並對應標籤', async () => {
+    const { c } = setup()
+    await c.ensureActivated()
+    await c.moodEvent('thanks')
+    const v = (await c.view())!
+    expect(v.mood.p).toBeCloseTo(0.15)
+    expect(v.label).toBe('興奮')
+  })
+
+  test('衰減依經過時間回到基線，半衰期 8 小時', async () => {
+    const { c, clock } = setup()
+    await c.ensureActivated()
+    await c.moodEvent('thanks')
+    clock.advance(8 * H)
+    expect((await c.view())!.mood.p).toBeCloseTo(0.075)
+    clock.advance(10 * DAY)
+    expect(Math.abs((await c.view())!.mood.p)).toBeLessThan(0.001)
+  })
+
+  test('高神經質衰減較慢', async () => {
+    const nervous = { ...MIKO, neuroticism: 100 }
+    const { c, clock } = setup([nervous])
+    await c.ensureActivated()
+    await c.moodEvent('thanks')
+    clock.advance(8 * H)
+    expect((await c.view())!.mood.p).toBeGreaterThan(0.09)
+  })
+
+  test('單軸每回合變化不超過 0.3，且不超出 ±1', async () => {
+    const { c } = setup()
+    await c.ensureActivated()
+    for (let i = 0; i < 10; i++) await c.moodEvent('scold')
+    expect((await c.view())!.mood.p).toBe(-1)
+    const { c: c2 } = setup()
+    await c2.ensureActivated()
+    await c2.moodEvent('scold')
+    expect((await c2.view())!.mood.p).toBeCloseTo(-0.2)
+  })
+
+  test('八分區標籤', async () => {
+    const { c } = setup()
+    await c.ensureActivated()
+    await c.moodEvent('scold')
+    expect((await c.view())!.label).toBe('焦慮')
+    await c.moodEvent('lateNight')
+    expect((await c.view())!.label).toBeTruthy()
+  })
+})
+
+describe('好感度', () => {
+  test('從 0 開始，每次 +0.01，每天上限 +0.05', async () => {
+    const { c } = setup()
+    await c.ensureActivated()
+    expect((await c.view())!.affinity).toBe(0)
+    for (let i = 0; i < 20; i++) await c.affinityEvent('meaningful')
+    expect((await c.view())!.affinity).toBeCloseTo(0.05)
+  })
+
+  test('隔天可繼續累積；負面事件 −0.03', async () => {
+    const { c, clock } = setup()
+    await c.ensureActivated()
+    for (let i = 0; i < 6; i++) await c.affinityEvent('meaningful')
+    clock.advance(DAY)
+    await c.affinityEvent('meaningful')
+    expect((await c.view())!.affinity).toBeCloseTo(0.06)
+    await c.affinityEvent('negative')
+    expect((await c.view())!.affinity).toBeCloseTo(0.03)
+  })
+
+  test('離開超過 7 天後緩慢回到 0', async () => {
+    const { c, clock } = setup()
+    await c.ensureActivated()
+    for (let i = 0; i < 5; i++) await c.affinityEvent('meaningful')
+    clock.advance(7 * DAY)
+    expect((await c.view())!.affinity).toBeCloseTo(0.05)
+    clock.advance(30 * DAY)
+    expect((await c.view())!.affinity).toBeCloseTo(0.025)
+  })
+
+  test('階段切換有遲滯', async () => {
+    const { c, clock } = setup()
+    await c.ensureActivated()
+    expect((await c.view())!.stage).toBe('陌生')
+    for (let d = 0; d < 6; d++) {
+      for (let i = 0; i < 5; i++) await c.affinityEvent('meaningful')
+      clock.advance(DAY)
+    }
+    expect((await c.view())!.affinity).toBeCloseTo(0.3)
+    expect((await c.view())!.stage).toBe('熟悉')
+    await c.affinityEvent('negative') // 0.27，仍在遲滯區間
+    expect((await c.view())!.stage).toBe('熟悉')
+    await c.affinityEvent('negative') // 0.24，低於降階門檻 0.25
+    expect((await c.view())!.stage).toBe('陌生')
+  })
+})
+
+describe('指令與設定', () => {
+  test('status 展開事實欄位與來源，查不到為 unknown', async () => {
+    const { c } = setup()
+    await c.ensureActivated()
+    const out = await c.command('status')
+    expect(out).toContain('月見ミコ')
+    expect(out).toContain('birthday：3/3（novel，信心 1，test）')
+    expect(out).toContain('bloodType：unknown')
+  })
+
+  test('setup 寫入共用 user.json，換角色不受影響', async () => {
+    const { c, fs } = setup()
+    await c.ensureActivated()
+    expect(await c.command('setup nickname=阿建 careLimit=3 quietStart=13:00 quietEnd=14:00')).toContain('設定已儲存')
+    const u = JSON.parse(fs.files.get(`${ROOT}/user.json`)!)
+    expect(u.nickname).toBe('阿建')
+    expect(u.careLimit).toBe(3)
+    expect(u.quiet).toEqual({ start: '13:00', end: '14:00' })
+    expect(await c.command('setup bogus=1')).toContain('無法解析')
+    expect((await c.getUser()).nickname).toBe('阿建')
+  })
+
+  test('預設角色白上吹雪的事實帶來源', async () => {
+    const fs = memoryFs()
+    const c = createCompanion({ fs, clock: fakeClock(), root: ROOT })
+    await c.ensureActivated()
+    const out = await c.command('status')
+    expect(out).toContain('白上吹雪')
+    expect(out).toContain('hololivepro.com')
+    expect(out).toContain('weight：unknown')
+  })
+})
diff --git a/plugins/cockpit/hooks/companion/core.ts b/plugins/cockpit/hooks/companion/core.ts
new file mode 100644
index 0000000..6a59a87
--- /dev/null
+++ b/plugins/cockpit/hooks/companion/core.ts
@@ -0,0 +1,167 @@
+import { idleDecay, initialAffinity, interact } from './affinity'
+import { FUBUKI } from './defaults'
+import { readJson, writeJson } from './fs'
+import type { Clock, Fs } from './fs'
+import { applyDelta, decay, MOOD_EVENTS, moodLabel } from './mood'
+import type { MoodEvent } from './mood'
+import { STAGES } from './types'
+import type { CompanionCore, CompanionState, Global, Pad, UserSettings } from './types'
+
+export const DEFAULT_USER: UserSettings = {
+  nickname: '',
+  wake: '08:00',
+  sleep: '23:00',
+  tz: '+0800',
+  careLimit: 5,
+  quiet: { start: '', end: '' },
+}
+
+export type View = {
+  core: CompanionCore
+  mood: Pad
+  label: string
+  kaomoji: string
+  affinity: number
+  stage: string
+  todos: number
+}
+
+export type CompanionOptions = { fs: Fs; clock: Clock; root: string; builtins?: CompanionCore[] }
+
+export function createCompanion({ fs, clock, root, builtins = [FUBUKI] }: CompanionOptions) {
+  const globalPath = `${root}/global.json`
+  const userPath = `${root}/user.json`
+  const dir = (id: string) => `${root}/companions/${id}`
+
+  const getGlobal = async (): Promise<Global> => (await readJson<Global>(fs, globalPath)) ?? { active: null, activatedOnce: false }
+  const getUser = async (): Promise<UserSettings> => ({ ...DEFAULT_USER, ...(await readJson<Partial<UserSettings>>(fs, userPath)) })
+  const getCore = (id: string) => readJson<CompanionCore>(fs, `${dir(id)}/core.json`)
+  const getState = (id: string) => readJson<CompanionState>(fs, `${dir(id)}/state.json`)
+  const putState = (id: string, s: CompanionState) => writeJson(fs, `${dir(id)}/state.json`, s)
+
+  async function install(core: CompanionCore) {
+    if (await getCore(core.id)) return
+    const now = clock.now()
+    await writeJson(fs, `${dir(core.id)}/core.json`, core)
+    await putState(core.id, { mood: { ...core.baseline, at: now }, affinity: initialAffinity(now), todos: 0 })
+  }
+
+  // 第一次啟用自動啟用預設角色；之後即使關閉也不會再自動啟用
+  async function ensureActivated(): Promise<{ first: boolean; name?: string }> {
+    const g = await getGlobal()
+    if (g.activatedOnce) return { first: false }
+    const def = builtins[0]
+    if (!def) return { first: false }
+    await install(def)
+    await writeJson(fs, globalPath, { active: def.id, activatedOnce: true })
+    return { first: true, name: def.name }
+  }
+
+  // 衰減只在讀取時計算，不寫回檔案
+  async function view(): Promise<View | null> {
+    const { active } = await getGlobal()
+    if (!active) return null
+    const core = await getCore(active)
+    const st = await getState(active)
+    if (!core || !st) return null
+    const now = clock.now()
+    const mood = decay(st.mood, core.baseline, now - st.mood.at, core.neuroticism)
+    const aff = idleDecay(st.affinity, now)
+    return { core, mood, ...moodLabel(mood), affinity: aff.value, stage: STAGES[aff.stage]!, todos: st.todos }
+  }
+
+  async function mutate(fn: (core: CompanionCore, st: CompanionState, now: number) => CompanionState) {
+    const { active } = await getGlobal()
+    if (!active) return
+    const core = await getCore(active)
+    const st = await getState(active)
+    if (!core || !st) return
+    await putState(active, fn(core, st, clock.now()))
+  }
+
+  async function moodEvent(ev: MoodEvent) {
+    await mutate((core, st, now) => {
+      const cur = decay(st.mood, core.baseline, now - st.mood.at, core.neuroticism)
+      return { ...st, mood: { ...applyDelta(cur, MOOD_EVENTS[ev]), at: now } }
+    })
+  }
+
+  async function affinityEvent(kind: 'meaningful' | 'negative') {
+    await mutate((_, st, now) => ({ ...st, affinity: interact(st.affinity, kind, now) }))
+  }
+
+  const bar = (v: number) => (v >= 0 ? '+' : '') + v.toFixed(2)
+
+  async function status(): Promise<string> {
+    const v = await view()
+    if (!v) return '目前沒有啟用角色。'
+    const lines = [`${v.kaomoji} ${v.core.name}｜${v.label}`]
+    lines.push(`心情 PAD：P ${bar(v.mood.p)} A ${bar(v.mood.a)} D ${bar(v.mood.d)}`)
+    lines.push(`好感：${v.stage}（${bar(v.affinity)}）`)
+    lines.push(`待辦：${v.todos}`)
+    lines.push('基本資訊：')
+    for (const [k, f] of Object.entries(v.core.facts)) {
+      lines.push(f === 'unknown' ? `  ${k}：unknown` : `  ${k}：${f.value}（${f.kind ?? '?'}，信心 ${f.confidence ?? '?'}，${f.source ?? '無來源'}）`)
+    }
+    return lines.join('\n')
+  }
+
+  async function available(): Promise<string[]> {
+    const ids = new Set(await fs.list(`${root}/companions`))
+    for (const b of builtins) ids.add(b.id)
+    return [...ids].sort()
+  }
+
+  async function switchTo(id: string): Promise<string> {
+    const builtin = builtins.find(b => b.id === id)
+    if (builtin) await install(builtin)
+    if (!(await getCore(id))) return `找不到角色「${id}」。可用：${(await available()).join('、') || '（無）'}`
+    const g = await getGlobal()
+    await writeJson(fs, globalPath, { ...g, active: id, activatedOnce: true })
+    return `已切換到 ${(await getCore(id))!.name}。`
+  }
+
+  async function setup(args: string[]): Promise<string> {
+    const u = await getUser()
+    const known = ['nickname', 'wake', 'sleep', 'tz', 'careLimit', 'quietStart', 'quietEnd']
+    const bad: string[] = []
+    for (const a of args) {
+      const i = a.indexOf('=')
+      const k = i < 0 ? a : a.slice(0, i)
+      const val = i < 0 ? '' : a.slice(i + 1)
+      if (!known.includes(k) || i < 0) bad.push(a)
+      else if (k === 'careLimit') {
+        const n = Number(val)
+        if (!Number.isInteger(n) || n < 0) bad.push(a)
+        else u.careLimit = n
+      } else if (k === 'quietStart') u.quiet.start = val
+      else if (k === 'quietEnd') u.quiet.end = val
+      else (u as Record<string, unknown>)[k] = val
+    }
+    if (bad.length) return `無法解析：${bad.join(' ')}\n用法：/cockpit setup nickname=… wake=HH:MM sleep=HH:MM tz=+0800 careLimit=N quietStart=HH:MM quietEnd=HH:MM`
+    if (args.length) await writeJson(fs, userPath, u)
+    return [
+      args.length ? '設定已儲存：' : '目前設定（以 key=value 修改）：',
+      `  nickname=${u.nickname}`,
+      `  wake=${u.wake} sleep=${u.sleep} tz=${u.tz}`,
+      `  careLimit=${u.careLimit} quietStart=${u.quiet.start} quietEnd=${u.quiet.end}`,
+    ].join('\n')
+  }
+
+  async function command(raw: string): Promise<string> {
+    const [sub = '', ...rest] = raw.trim().split(/\s+/).filter(Boolean)
+    if (sub === 'status') return status()
+    if (sub === 'switch') return rest[0] ? switchTo(rest[0]) : `用法：/cockpit switch <角色>。可用：${(await available()).join('、')}`
+    if (sub === 'companion' && rest[0] === 'off') {
+      const g = await getGlobal()
+      await writeJson(fs, globalPath, { ...g, active: null, activatedOnce: true })
+      return '助理已關閉，所有資料保留。'
+    }
+    if (sub === 'setup') return setup(rest)
+    return '用法：/cockpit status | switch <角色> | companion off | setup [key=value…]'
+  }
+
+  return { ensureActivated, view, moodEvent, affinityEvent, command, getUser }
+}
+
+export type Companion = ReturnType<typeof createCompanion>
diff --git a/plugins/cockpit/hooks/companion/defaults.ts b/plugins/cockpit/hooks/companion/defaults.ts
new file mode 100644
index 0000000..16f5810
--- /dev/null
+++ b/plugins/cockpit/hooks/companion/defaults.ts
@@ -0,0 +1,22 @@
+import type { CompanionCore } from './types'
+
+const OFFICIAL = 'https://hololive.hololivepro.com/en/talents/shirakami-fubuki/'
+
+// 只放帶來源的事實欄位與官方公開的招牌短語；個性、記憶、口癖表在本機生成，不進 repo
+export const FUBUKI: CompanionCore = {
+  id: 'fubuki',
+  name: '白上吹雪',
+  facts: {
+    birthday: { value: '10/5', source: OFFICIAL, kind: 'official', confidence: 1 },
+    zodiac: { value: '天秤座', source: `${OFFICIAL}（由生日推得）`, kind: 'official', confidence: 0.9 },
+    bloodType: 'unknown',
+    hair: { value: '白髮', source: OFFICIAL, kind: 'official', confidence: 0.8 },
+    face: 'unknown',
+    height: { value: '155cm', source: OFFICIAL, kind: 'official', confidence: 1 },
+    weight: 'unknown',
+    measurements: 'unknown',
+  },
+  phrases: ['Good foxy day!', 'Hi, Friends!'],
+  neuroticism: 50,
+  baseline: { p: 0.2, a: 0.1, d: 0.1 },
+}
diff --git a/plugins/cockpit/hooks/companion/fs.ts b/plugins/cockpit/hooks/companion/fs.ts
new file mode 100644
index 0000000..fc277dc
--- /dev/null
+++ b/plugins/cockpit/hooks/companion/fs.ts
@@ -0,0 +1,58 @@
+// 檔案系統與時鐘皆由外部注入；核心只依賴這兩個介面
+export interface Fs {
+  read(path: string): Promise<string | null>
+  write(path: string, data: string): Promise<void>
+  rename(from: string, to: string): Promise<void>
+  list(dir: string): Promise<string[]>
+}
+
+export type Clock = { now(): number }
+
+// 先寫暫存檔再 rename，當機時不會留下寫到一半的檔案
+export async function writeAtomic(fs: Fs, path: string, data: string): Promise<void> {
+  const tmp = `${path}.tmp`
+  await fs.write(tmp, data)
+  await fs.rename(tmp, path)
+}
+
+export async function readJson<T>(fs: Fs, path: string): Promise<T | null> {
+  const raw = await fs.read(path)
+  if (raw === null) return null
+  try {
+    return JSON.parse(raw) as T
+  } catch {
+    return null
+  }
+}
+
+export const writeJson = (fs: Fs, path: string, value: unknown) => writeAtomic(fs, path, JSON.stringify(value, null, 2))
+
+export function memoryFs(seed: Record<string, string> = {}): Fs & { files: Map<string, string> } {
+  const files = new Map(Object.entries(seed))
+  return {
+    files,
+    async read(path) {
+      return files.get(path) ?? null
+    },
+    async write(path, data) {
+      files.set(path, data)
+    },
+    async rename(from, to) {
+      const v = files.get(from)
+      if (v === undefined) throw new Error(`ENOENT: ${from}`)
+      files.delete(from)
+      files.set(to, v)
+    },
+    async list(dir) {
+      const prefix = dir.endsWith('/') ? dir : dir + '/'
+      const names = new Set<string>()
+      for (const k of files.keys()) if (k.startsWith(prefix)) names.add(k.slice(prefix.length).split('/')[0]!)
+      return [...names].filter(n => !n.endsWith('.tmp')).sort()
+    },
+  }
+}
+
+export function fakeClock(start = Date.parse('2026-10-12T00:00:00Z')) {
+  let t = start
+  return { now: () => t, advance: (ms: number) => void (t += ms), set: (ms: number) => void (t = ms) }
+}
diff --git a/plugins/cockpit/hooks/companion/mood.ts b/plugins/cockpit/hooks/companion/mood.ts
new file mode 100644
index 0000000..23c8323
--- /dev/null
+++ b/plugins/cockpit/hooks/companion/mood.ts
@@ -0,0 +1,60 @@
+import type { Pad } from './types'
+
+export const clamp = (x: number, lo = -1, hi = 1) => Math.max(lo, Math.min(hi, x))
+
+const HOUR = 3_600_000
+const MOOD_HALF_LIFE_H = 8
+
+// 高神經質的角色情緒消退較慢：50 為基準，0→0.5 倍，100→1.5 倍
+export const halfLife = (neuroticism: number) => MOOD_HALF_LIFE_H * HOUR * (0.5 + neuroticism / 100)
+
+// 讀檔時才計算：x = B + (x − B)·0.5^(Δ/τ)
+export function decay(mood: Pad, baseline: Pad, elapsedMs: number, neuroticism: number): Pad {
+  if (elapsedMs <= 0) return { p: mood.p, a: mood.a, d: mood.d }
+  const k = Math.pow(0.5, elapsedMs / halfLife(neuroticism))
+  return {
+    p: baseline.p + (mood.p - baseline.p) * k,
+    a: baseline.a + (mood.a - baseline.a) * k,
+    d: baseline.d + (mood.d - baseline.d) * k,
+  }
+}
+
+// 單軸每回合變化上限 ±0.3
+export const TURN_CAP = 0.3
+
+export function applyDelta(mood: Pad, delta: Pad): Pad {
+  const step = (x: number, dx: number) => clamp(x + clamp(dx, -TURN_CAP, TURN_CAP))
+  return { p: step(mood.p, delta.p), a: step(mood.a, delta.a), d: step(mood.d, delta.d) }
+}
+
+export const MOOD_EVENTS = {
+  thanks: { p: 0.15, a: 0.05, d: 0.05 },
+  scold: { p: -0.2, a: 0.15, d: -0.1 },
+  success: { p: 0.08, a: 0.03, d: 0.05 },
+  toolFail: { p: -0.08, a: 0.1, d: -0.08 },
+  return: { p: 0.1, a: 0.08, d: 0 },
+  lateNight: { p: -0.05, a: -0.1, d: 0 },
+  favorite: { p: 0.12, a: 0.08, d: 0.03 },
+  ignored: { p: -0.05, a: -0.03, d: -0.03 },
+} as const satisfies Record<string, Pad>
+export type MoodEvent = keyof typeof MOOD_EVENTS
+
+// 八分區（Mehrabian 的 PAD 八分類）→ 情緒標籤與顏文字
+const OCTANTS: Record<string, { label: string; kaomoji: string }> = {
+  '+++': { label: '興奮', kaomoji: '(≧▽≦)' },
+  '++-': { label: '撒嬌', kaomoji: '(๑>ᴗ<๑)' },
+  '+-+': { label: '放鬆', kaomoji: '(´ᴗ`)' },
+  '+--': { label: '溫順', kaomoji: '(︶ᴗ︶)' },
+  '---': { label: '無聊', kaomoji: '(－_－)' },
+  '--+': { label: '不屑', kaomoji: '(￢_￢)' },
+  '-++': { label: '生氣', kaomoji: '(╬`益´)' },
+  '-+-': { label: '焦慮', kaomoji: '(；´Д`)' },
+}
+const CALM = { label: '平靜', kaomoji: '(・ω・)' }
+const CALM_RADIUS = 0.1
+
+export function moodLabel(m: Pad): { label: string; kaomoji: string } {
+  if (Math.abs(m.p) < CALM_RADIUS && Math.abs(m.a) < CALM_RADIUS && Math.abs(m.d) < CALM_RADIUS) return CALM
+  const s = (x: number) => (x >= 0 ? '+' : '-')
+  return OCTANTS[s(m.p) + s(m.a) + s(m.d)]!
+}
diff --git a/plugins/cockpit/hooks/companion/node-fs.ts b/plugins/cockpit/hooks/companion/node-fs.ts
new file mode 100644
index 0000000..a06a9a2
--- /dev/null
+++ b/plugins/cockpit/hooks/companion/node-fs.ts
@@ -0,0 +1,26 @@
+import { mkdir, readdir, readFile, rename, writeFile } from 'node:fs/promises'
+import { dirname } from 'node:path'
+
+import type { Fs } from './fs'
+
+export const nodeFs: Fs = {
+  async read(path) {
+    try {
+      return await readFile(path, 'utf8')
+    } catch {
+      return null
+    }
+  },
+  async write(path, data) {
+    await mkdir(dirname(path), { recursive: true })
+    await writeFile(path, data, 'utf8')
+  },
+  rename,
+  async list(dir) {
+    try {
+      return (await readdir(dir)).filter(n => !n.endsWith('.tmp')).sort()
+    } catch {
+      return []
+    }
+  },
+}
diff --git a/plugins/cockpit/hooks/companion/types.ts b/plugins/cockpit/hooks/companion/types.ts
new file mode 100644
index 0000000..e2f18ae
--- /dev/null
+++ b/plugins/cockpit/hooks/companion/types.ts
@@ -0,0 +1,46 @@
+export type Pad = { p: number; a: number; d: number }
+
+export type Source = 'novel' | 'official' | 'wiki'
+
+export type Fact = { value: string; source?: string; kind?: Source; confidence?: number }
+
+export const FACT_KEYS = ['birthday', 'zodiac', 'bloodType', 'hair', 'face', 'height', 'weight', 'measurements'] as const
+export type FactKey = (typeof FACT_KEYS)[number]
+
+export type CompanionCore = {
+  id: string
+  name: string
+  facts: Record<FactKey, Fact | 'unknown'>
+  phrases?: string[]
+  // 神經質 0~100，影響心情半衰期；個性推導屬於後續里程碑，先用預設值
+  neuroticism: number
+  baseline: Pad
+}
+
+export const STAGES = ['陌生', '熟悉', '親近', '特別'] as const
+export type Stage = (typeof STAGES)[number]
+
+export type Affinity = {
+  value: number
+  stage: number
+  dayKey: string
+  dayGain: number
+  lastSeen: number
+}
+
+export type CompanionState = {
+  mood: Pad & { at: number }
+  affinity: Affinity
+  todos: number
+}
+
+export type UserSettings = {
+  nickname: string
+  wake: string
+  sleep: string
+  tz: string
+  careLimit: number
+  quiet: { start: string; end: string }
+}
+
+export type Global = { active: string | null; activatedOnce: boolean }
diff --git a/plugins/cockpit/hooks/hud/format.ts b/plugins/cockpit/hooks/hud/format.ts
index 0d93cdd..7628f4c 100644
--- a/plugins/cockpit/hooks/hud/format.ts
+++ b/plugins/cockpit/hooks/hud/format.ts
@@ -232,3 +232,9 @@ export function parseDf(out: string): number | undefined {
   const m = row && /(\d+)%/.exec(row)
   return m ? Number(m[1]) : undefined
 }
+
+// band 的所有行：第一行恆為 HUD；有角色時才多第二行角色行
+export function bandLines(d: HudData, columns: number, compact: boolean, companion: Seg[] | null): Seg[][] {
+  const first = fit(d, columns, compact)
+  return companion ? [first, companion] : [first]
+}
diff --git a/plugins/cockpit/hooks/hud/index.tsx b/plugins/cockpit/hooks/hud/index.tsx
index 03ac216..f5fe744 100644
--- a/plugins/cockpit/hooks/hud/index.tsx
+++ b/plugins/cockpit/hooks/hud/index.tsx
@@ -2,7 +2,10 @@ import { atom, read, update } from 'claude-code'
 import type { EngineInterface, Register, SessionContextUsage, SessionRateLimit } from 'claude-code'
 
 import type { Mode, Sys, Usage } from '../../types'
-import { cpuPercent, fit, parseCpu, parseDf, parseGit, parseMem, parseOffset } from './format'
+import { fitCompanion } from '../companion/band'
+import { createCompanion } from '../companion/core'
+import { nodeFs } from '../companion/node-fs'
+import { bandLines, cpuPercent, parseCpu, parseDf, parseGit, parseMem, parseOffset } from './format'
 import type { CpuSample } from './format'
 
 const usageAtom = atom({ plugin: 'cockpit', key: 'usage' } as const, {})
@@ -34,6 +37,7 @@ function toUsage(context: SessionContextUsage, rateLimits: SessionRateLimit[]):
 }
 
 let home: string | undefined
+let companion: ReturnType<typeof createCompanion> | undefined
 let tzOffsetMin = 0
 let prevCpu: CpuSample | null = null
 let ticks = 0
@@ -95,8 +99,8 @@ export const register: Register = on => {
   on('session.start', async ($, e, next) => {
     await $.command.register({
       name: 'cockpit',
-      description: 'Cockpit 控制：hud 狀態列',
-      argumentHint: 'hud on | off | compact',
+      description: 'Cockpit 控制：助理（status、switch、companion off、setup）與 hud 狀態列',
+      argumentHint: 'status | switch <角色> | companion off | setup | hud on | off | compact',
     })
     // 別名：/hud <arg> 等同 /cockpit hud <arg>
     await $.command.register({
@@ -105,6 +109,9 @@ export const register: Register = on => {
       argumentHint: 'on | off | compact',
     })
     home = await $.env.get('HOME')
+    companion = createCompanion({ fs: nodeFs, clock: { now: Date.now }, root: `${home ?? ''}/.cockpit` })
+    const first = await companion.ensureActivated()
+    if (first.first) $.ui.toast(`已啟用 ${first.name}。用 /cockpit companion off 可關閉`)
     try {
       const r = await $.process.run(['date', '+%z'], { timeoutMs: 3000 })
       tzOffsetMin = parseOffset(r.stdout)
@@ -147,41 +154,42 @@ export const register: Register = on => {
 
   on('command.run', { command: 'cockpit' }, async ($, e, next) => {
     const [sub, ...rest] = e.args.trim().split(/\s+/)
-    if (sub !== 'hud') return { text: '用法：/cockpit hud on | off | compact' }
+    if (sub === 'hud') return runHud($, rest.join(' '))
 
-    return runHud($, rest.join(' '))
+    return { text: companion ? await companion.command(e.args) : '尚未就緒。' }
   })
 
   on('ui.render', { component: 'AbovePrompt' }, async ($, e, next) => {
     const mode = await read($, modeAtom)
     if (e.props.hasSurvey || mode === 'off') return next(e)
 
-    const line = fit(
-      {
-        model: await $.session.model(),
-        cwd: await $.session.cwd(),
-        home,
-        git: await read($, gitAtom),
-        usage: await read($, usageAtom),
-        sys: await read($, sysAtom),
-        tzOffsetMin,
-        effort: await read($, effortAtom),
-      },
-      e.props.bodyColumns,
-      mode === 'compact',
-    )
+    const data = {
+      model: await $.session.model(),
+      cwd: await $.session.cwd(),
+      home,
+      git: await read($, gitAtom),
+      usage: await read($, usageAtom),
+      sys: await read($, sysAtom),
+      tzOffsetMin,
+      effort: await read($, effortAtom),
+    }
+    const view = await companion?.view()
+    const cols = e.props.bodyColumns
+    const lines = bandLines(data, cols, mode === 'compact', view ? fitCompanion(view, cols, mode === 'compact') : null)
     const { Box, Text } = $.ui.resolve(e)
 
     // 引擎在 band 與輸入框之間已留一行空白，上方補一行讓上下間距相同
     return (
-      <Box marginTop={1}>
-        <Text wrap="truncate">
-          {line.map(s => (
-            <Text color={s.color} dimColor={s.dim} bold={s.bold}>
-              {s.text}
-            </Text>
-          ))}
-        </Text>
+      <Box marginTop={1} flexDirection="column">
+        {lines.map(line => (
+          <Text wrap="truncate">
+            {line.map(s => (
+              <Text color={s.color} dimColor={s.dim} bold={s.bold}>
+                {s.text}
+              </Text>
+            ))}
+          </Text>
+        ))}
       </Box>
     )
   })