diff --git a/changelog.d/805-instance-health.changed.md b/changelog.d/805-instance-health.changed.md
new file mode 100644
index 00000000..9889303b
--- /dev/null
+++ b/changelog.d/805-instance-health.changed.md
@@ -0,0 +1 @@
+The FlyBot instance card now shows a status badge, a human-readable health reason, the last health-check time and the relevant Start/Stop/Reinitialize action, while the raw bridge error stays in a technical disclosure instead of the page message.
diff --git a/docs/architecture.md b/docs/architecture.md
index 6a2b8765..24717c68 100644
--- a/docs/architecture.md
+++ b/docs/architecture.md
@@ -1553,6 +1553,13 @@ Run/Plan/Review until the state is fixed. A danger zone offers stop scheduling,
 stop FlyBot and delete; deletion requires typing the repository name and removes
 the Fledge connection, instance, jobs and tokens without touching GitHub.
 
+The FlyBot instance card maps transport failures to a short reason (`Bridge
+unreachable`, `Bridge returned 502`, `Container is not running`, `Model endpoint
+unreachable`) and keeps the raw error in a technical disclosure. The page-level
+message uses the same reason, never a bare `TypeError: fetch failed`, and the
+card shows the last health-check time and the Start/Stop/Reinitialize action for
+the current state.
+
 ### Pull-request delivery
 
 Each repository page has a delivery list of iterate jobs with open pull requests,
diff --git a/public/app.css b/public/app.css
index 9338c641..9080f9d3 100644
--- a/public/app.css
+++ b/public/app.css
@@ -1093,6 +1093,9 @@ a.list-row:hover strong { color: var(--accent); }
   border: 1px solid var(--line); border-radius: var(--radius-md); background: var(--paper);
 }
 .workspace-toolbar { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
+[data-instance-health] .badge { vertical-align: baseline; }
+[data-instance-health] details { margin-top: 8px; }
+[data-instance-health] pre { margin: 6px 0 0; font-size: var(--text-sm); white-space: pre-wrap; overflow-wrap: anywhere; }
 
 .add-choice { border: 1px solid var(--line); border-radius: var(--radius-md); padding: 14px; margin-bottom: 12px; }
 .add-choice h3 { margin: 0 0 6px; font-size: 15px; }
diff --git a/src/views/pages.ts b/src/views/pages.ts
index c6da7eb5..243019de 100644
--- a/src/views/pages.ts
+++ b/src/views/pages.ts
@@ -299,6 +299,24 @@ function statusLabel(t: Translate, status: string): string {
   return labels[status] ?? status
 }
 
+// #805: the status answers "why is this not ready" on its own; `last_error` only
+// explains a failure. `Instances.stop()` leaves the previous `last_error` in place
+// and a starting instance has none, so reading that column for every non-ready
+// status called a stopped instance healthy. Only `failed` reads the error, and an
+// empty error there means a failed check, never a healthy one.
+function instanceReason(t: Translate, status: string, error: string | null | undefined): string {
+  if (status === 'ready') return t('健康检查正常', 'Health check ok')
+  if (status === 'stopped') return t('实例已停止，不会接受新任务', 'The instance is stopped and takes no new jobs')
+  if (status === 'starting') return t('实例正在创建，还未就绪', 'The instance is being created and is not ready yet')
+  if (status === 'provisioning') return t('实例正在初始化，还未就绪', 'The instance is being provisioned and is not ready yet')
+  const text = String(error ?? '').toLowerCase()
+  if (/\b502\b/.test(text)) return t('Bridge 返回 502', 'Bridge returned 502')
+  if (/fetch failed|econnrefused|enotfound|etimedout|network/.test(text)) return t('Bridge 无法连接', 'Bridge unreachable')
+  if (/container|docker|not running/.test(text)) return t('容器未运行', 'Container is not running')
+  if (/model|gateway|provider/.test(text)) return t('模型端点不可达', 'Model endpoint unreachable')
+  return t('健康检查失败', 'Health check failed')
+}
+
 // A webhook delivery stores its state as an internal code. The console names the
 // three states in the reader's language and keeps the code only as the filter
 // value, so `/admin/webhooks?status=` links keep filtering exactly as before.
@@ -1404,6 +1422,22 @@ export function repoPage(input: { config: Config; locale: Locale; viewer: Viewer
     : runnable
       ? { body: t('立即运行会创建这个仓库的第一个任务；每次运行只开一个 PR。', 'Run now creates the first job for this repository; each run opens at most one pull request.'), action: { formAction: `/repos/${repo.id}/run`, label: t('立即运行', 'Run now'), csrf: csrf(viewer) } }
       : { body: t('先修复 FlyBot 实例或 GitHub 凭据，然后再运行。', 'Fix the FlyBot instance or the GitHub credential first, then run.'), action: { label: t('实例与凭据在本页的连接卡片里。', 'The instance and the credential are on the connection card of this page.') } }
+  const instanceHealthTone = config.flybot.instanceImage === ''
+    ? 'busy'
+    : instance === undefined
+      ? 'busy'
+      : instance.status === 'ready'
+        ? 'good'
+        : instance.status === 'failed' ? 'bad' : 'busy'
+  const instanceHealthStatus = config.flybot.instanceImage === ''
+    ? t('未启用', 'not enabled')
+    : instance === undefined ? t('未创建', 'not created') : statusLabel(t, instance.status)
+  const instanceHealthReason = config.flybot.instanceImage === ''
+    ? t('这个部署没有启用每仓库 FlyBot 实例。', 'This deployment has no per-repository FlyBot instance.')
+    : instance === undefined
+      ? t('实例尚未创建。', 'The instance has not been created yet.')
+      : instanceReason(t, instance.status, instance.last_error)
+  const instanceLastHealth = instance === undefined || instance.last_health_at === null ? t('未知', 'unknown') : humanTimeShort(instance.last_health_at)
   // #472 slice 3: the instance state is a page-level message, not a banner in the
   // team card. `failed` is an error; any other non-ready state is informational.
   if (config.flybot.instanceImage === '') {
@@ -1414,7 +1448,7 @@ export function repoPage(input: { config: Config; locale: Locale; viewer: Viewer
     pageMessages.push({
       level: instance.status === 'failed' ? 'error' : 'warning',
       key: 'instance-status',
-      text: `${t(`FlyBot 实例状态：${statusLabel(t, instance.status)}`, `FlyBot instance status: ${statusLabel(t, instance.status)}`)}${instance.last_error === null ? '' : ` · ${instance.last_error}`}`,
+      text: `${t('FlyBot 实例：', 'FlyBot instance: ')}${instanceHealthStatus} · ${instanceHealthReason}`,
     })
   }
   const instanceActions = config.flybot.instanceImage === ''
@@ -1486,12 +1520,14 @@ export function repoPage(input: { config: Config; locale: Locale; viewer: Viewer
     <p class="muted">${escapeHtml(t('读出开着的 issue 和 PR，按优先级排序、标出重复项，并点名下一项。只读：不开分支，也不开 PR。', 'Reads the open issues and pull requests, ranks them by priority, links duplicates and names the next item. Read-only: no branch and no pull request.'))}</p>
     ${triageForm}
   </section>`
-  const instanceCard = `<section class="card">
+  const instanceCard = `<section class="card" data-instance-health>
     <div class="row between">
       <div>
         <div class="eyebrow">${escapeHtml(t('每仓库 FlyBot', 'PER-REPOSITORY FLYBOT'))}</div>
         <h2>${escapeHtml(advanced ? t('实例与团队', 'Instance & team') : t('FlyBot 状态', 'FlyBot status'))}</h2>
-        <p class="muted">${instance === undefined ? escapeHtml(t('未创建', 'Not created')) : `${badge(t, instance.status)}${advanced ? ` <span class="muted">${escapeHtml(instance.container)}</span>` : ''}`}${instanceReady && advanced ? ` · ${escapeHtml(t('任务先发给总控，再由负责人执行', 'jobs go to the Chief, then the Lead'))}` : ''}</p>
+        <p class="muted"><span class="badge ${instanceHealthTone}">${escapeHtml(instanceHealthStatus)}</span> · ${escapeHtml(instanceHealthReason)}</p>
+        <p class="fine">${escapeHtml(t('最近检查', 'Last health check'))} ${escapeHtml(instanceLastHealth)}${advanced && instance !== undefined ? ` · ${escapeHtml(instance.container)}` : ''}${instanceReady && advanced ? ` · ${escapeHtml(t('任务先发给总控，再由负责人执行', 'jobs go to the Chief, then the Lead'))}` : ''}</p>
+        ${instance === undefined || instance.last_error === null ? '' : `<details class="advanced-help"><summary>${escapeHtml(t('技术详情', 'Technical detail'))}</summary><pre>${escapeHtml(instance.last_error)}</pre></details>`}
       </div>
       ${advanced ? instanceActions : ''}
     </div>
diff --git a/test/pages.test.ts b/test/pages.test.ts
index 53e6d3c8..040a04bd 100644
--- a/test/pages.test.ts
+++ b/test/pages.test.ts
@@ -2064,3 +2064,83 @@ test('both repository lists translate the reviewer badge', () => {
     store.close()
   }
 })
+
+// #805: the status decides the sentence; `last_error` only explains a failure.
+// `Instances.stop()` keeps the previous error and a starting instance has none, so
+// every non-ready state must say what it is doing, in both languages, with its own
+// action — and only `failed` may report a health failure.
+test('every FlyBot instance state names itself, its own action and never calls a non-ready instance healthy', () => {
+  const config = testConfig({ flybot: { ...testConfig().flybot, instanceImage: 'image' } })
+  const store = new Store(':memory:')
+  try {
+    const user = makeUser(store, { login: 'instance-health-user', status: 'approved', superadmin: true })
+    const viewer = { user: store.userById(user.id)!, csrfToken: 'csrf' }
+    const repo = store.createRepo({ id: 'repo_instance_health', userId: user.id, owner: 'o', name: 'health', defaultBranch: 'main', tokenEnc: 'x', permission: 'admin', repoRole: 'maintainer', goal: '', autoIterate: false, intervalMinutes: 1440 })
+    const saveInstance = (status: string, lastError: string | null): void => {
+      store.saveRepoInstance({
+        repo_id: repo.id, user_id: user.id, container: 'fledge-health', network: 'n', data_dir: '/tmp/health', bridge_script: '/tmp/bridge',
+        dsh_port: 1, bridge_port: 2, model_port: 3, model_bind: '127.0.0.1', image: 'image', status, chief_session: 'c',
+        team_json: null, bridge_token_enc: 'x', bridge_pid: null, log_pid: null, last_error: lastError,
+        created_at: '2026-11-15T08:00:00.000Z', updated_at: '2026-11-15T08:00:00.000Z', last_health_at: '2026-11-15T08:00:00.000Z',
+      })
+    }
+    const instanceCard = (html: string): string => {
+      const start = html.indexOf('data-instance-health')
+      assert.notEqual(start, -1, 'the Team section has the structured instance card')
+      const end = html.indexOf('</section>', start)
+      assert.notEqual(end, -1, 'the instance card closes')
+      return html.slice(start, end)
+    }
+    const summaryLine = (html: string): string => {
+      const card = instanceCard(html)
+      const end = card.indexOf('</p>')
+      assert.notEqual(end, -1, 'the instance card has a summary line')
+      return card.slice(0, end)
+    }
+    const cases = [
+      { status: 'ready', lastError: null, zhBadge: '就绪', enBadge: 'Ready', zhReason: '健康检查正常', enReason: 'Health check ok', zhAction: '停止 FlyBot', enAction: 'Stop FlyBot', action: 'instance/stop' },
+      { status: 'failed', lastError: 'TypeError: fetch failed', zhBadge: '失败', enBadge: 'Failed', zhReason: 'Bridge 无法连接', enReason: 'Bridge unreachable', zhAction: '启动 FlyBot', enAction: 'Start FlyBot', action: 'instance' },
+      { status: 'failed', lastError: null, zhBadge: '失败', enBadge: 'Failed', zhReason: '健康检查失败', enReason: 'Health check failed', zhAction: '启动 FlyBot', enAction: 'Start FlyBot', action: 'instance' },
+      { status: 'stopped', lastError: 'health check failed: stopped from the console', zhBadge: '已停止', enBadge: 'Stopped', zhReason: '实例已停止，不会接受新任务', enReason: 'The instance is stopped and takes no new jobs', zhAction: '启动 FlyBot', enAction: 'Start FlyBot', action: 'instance' },
+      { status: 'starting', lastError: null, zhBadge: '启动中', enBadge: 'Starting', zhReason: '实例正在创建，还未就绪', enReason: 'The instance is being created and is not ready yet', zhAction: '重新初始化 FlyBot', enAction: 'Reinitialize FlyBot', action: 'instance' },
+      { status: 'provisioning', lastError: 'TypeError: fetch failed', zhBadge: '初始化中', enBadge: 'Provisioning', zhReason: '实例正在初始化，还未就绪', enReason: 'The instance is being provisioned and is not ready yet', zhAction: '重新初始化 FlyBot', enAction: 'Reinitialize FlyBot', action: 'instance' },
+    ]
+    for (const state of cases) {
+      saveInstance(state.status, state.lastError)
+      const instance = store.getRepoInstance(repo.id)!
+      const zh = repoPage({ config, locale: 'zh', viewer, repo, instance, jobs: [] })
+      const en = repoPage({ config, locale: 'en', viewer, repo, instance, jobs: [] })
+      const name = `${state.status} (${state.lastError === null ? 'no error' : 'an old error on the row'})`
+      assert.ok(instanceCard(zh).includes(state.zhBadge), `${name}: the zh card carries the status badge`)
+      assert.ok(instanceCard(en).includes(state.enBadge), `${name}: the en card carries the status badge`)
+      assert.ok(instanceCard(zh).includes(state.zhReason), `${name}: the zh card names the state`)
+      assert.ok(instanceCard(en).includes(state.enReason), `${name}: the en card names the state`)
+      assert.ok(instanceCard(zh).includes(state.zhAction), `${name}: the zh card offers its own action`)
+      assert.ok(instanceCard(en).includes(state.enAction), `${name}: the en card offers its own action`)
+      assert.ok(instanceCard(zh).includes(`action="/repos/${repo.id}/${state.action}"`), `${name}: the zh action posts its own form`)
+      assert.ok(instanceCard(en).includes(`action="/repos/${repo.id}/${state.action}"`), `${name}: the en action posts its own form`)
+      if (state.status === 'ready') {
+        assert.ok(!en.includes('FlyBot instance:'), 'a ready instance raises no page-level message')
+        assert.ok(!en.includes('Health check failed'), 'a ready instance never reports a failure')
+        continue
+      }
+      assert.ok(summaryLine(zh).includes(state.zhReason), `${name}: the zh summary line carries the reason, not the raw error`)
+      assert.ok(!instanceCard(zh).includes('健康检查正常'), `${name}: a non-ready instance is never called healthy in zh`)
+      assert.ok(!instanceCard(en).includes('Health check ok'), `${name}: a non-ready instance is never called healthy in en`)
+      assert.ok(!zh.includes('健康检查正常'), `${name}: the zh page never calls a non-ready instance healthy`)
+      assert.ok(!en.includes('Health check ok'), `${name}: the en page never calls a non-ready instance healthy`)
+      assert.ok(zh.includes(`FlyBot 实例：${state.zhBadge} · ${state.zhReason}`), `${name}: the zh page message repeats the status and the reason`)
+      assert.ok(en.includes(`FlyBot instance: ${state.enBadge} · ${state.enReason}`), `${name}: the en page message repeats the status and the reason`)
+      if (state.lastError !== null && state.status !== 'failed') {
+        assert.ok(!summaryLine(en).includes(state.lastError), `${name}: an old error is not the reason of a non-failed state`)
+      }
+      if (state.lastError !== null) {
+        assert.ok(instanceCard(en).includes('Technical detail'), `${name}: the raw error stays behind the disclosure`)
+        assert.ok(instanceCard(en).includes(state.lastError), `${name}: the disclosure keeps the original text`)
+        assert.ok(!en.slice(0, en.indexOf('data-instance-health')).includes(state.lastError), `${name}: the raw error is not the page-level message`)
+      }
+    }
+  } finally {
+    store.close()
+  }
+})