diff --git a/docs/PROGRESS_LOG.md b/docs/PROGRESS_LOG.md
index 3417a3f..5bb151f 100644
--- a/docs/PROGRESS_LOG.md
+++ b/docs/PROGRESS_LOG.md
@@ -146,6 +146,18 @@
 - **commit**: <hash 或 N/A>
 ======================================================= -->
 
+### 2026-06-30 · v0.6 项目详情页 — branch/worktree + 详细 active session
+
+- **状态**: `[x]` DONE。**452 测试全绿**(+21)· 双 typecheck 干净 · `build:web` OK · 覆盖率 90.16/81.32(`worktrees.ts` 100% / `projects.ts` 93.8%)· 真端到端(curl + 真浏览器)验证通过。
+- **需求**(用户): 每个 project 的**详情页**——详细显示具体 active 的 session,以及具体的 **branch 或 worktree**。
+- **设计**: 点项目卡的**名字**进入应用内详情视图(`renderProjectDetail`,在 Projects 面板内切换,带"← All projects"返回)。分区:① 头部(名/路径/branch chip/dirty)② **Branch / Worktrees**(`git worktree list` 每条:branch 或 `detached @ head` + main/current/locked/prunable 标签 + 路径;单 worktree 即显示分支)③ **Active sessions(N)**(每条:状态点 + 标题 + `状态·👁设备数·started 多久前` + **Open** + **Kill ✕**)④ **Start** 启动器行(复用 Claude/Codex/Code)。再进 Projects 总是回到网格(不残留详情)。
+- **后端**: 新增 `src/http/worktrees.ts`(`parseWorktrees`(纯)+ `listWorktrees`,`git worktree list --porcelain`,execFile 无 shell,2s 超时,best-effort→[]);`projects.ts` 加 `buildProjectDetail(cfg, path, liveSessions)`(校验绝对存在目录→否则 null;复用 readBranch/readDirty/hasGitEntry/matchSessions;**不缓存**,详情按需要新鲜)。`src/server.ts` `GET /projects/detail?path=`(只读、无 Origin 守卫,同 /projects;path 缺→400、非法/不存在→404)。types 加 `WorktreeInfo`/`ProjectDetail`。
+- **前端**(`public/projects.ts` + style): `fetchProjectDetail`/`killSession`;`makeProjectCard` 加可选 `onOpenDetail`(名字变可点链接 `.proj-name-link`);`mountProjects` 加 grid↔detail 视图切换 + 自动刷新路由(详情每 5s 刷新);Kill 走 `DELETE /live-sessions/:id`(同源带 Origin)。详情视图样式 `.proj-detail*`/`.proj-wt-*`/`.proj-dsession*`。session meta 在 status=unknown 时省略状态点(不显示 `· ·`)。
+- **测试**(+21): `test/worktrees.test.ts`(parse:单/多/detached/locked/prunable/无尾空行/空);`projects.test.ts` buildProjectDetail(相对/不存在/文件→null、非 git 目录、假 repo 读 branch、session 按 cwd 前缀归并、**真 git init worktree**(realpath 规避 /var symlink));`projects-panel.test.ts` renderProjectDetail(null→not found+Back、头部、worktree 行+current tag、detached、session Open/Kill 接线+忽略 exited、空态+启动器、非 git)+ 名字链接。
+- **验证**: `npx tsc`(双)干净;`npx vitest run --coverage` 452/452(≥80×4);真浏览器:开 web-terminal 的 Claude session→进详情→显示 branch `v0.6-projects`(MAIN/CURRENT)+ Active sessions(1)(web-terminal,👁1,Open/✕)+ Start 启动器 + 返回。curl `/projects/detail` 返回 worktree(main/current/head)+ 缺/相对 path→400/404。
+- **安全**: `/projects/detail` 只读(git branch/status/worktree-list,execFile 无 shell + 超时),path 校验绝对存在目录;与 /projects 同威胁模型(不新增可变更面)。
+- **commit**: (本次提交)
+
 ### 2026-06-30 · v0.6 项目卡启动器 — Claude · Codex · VS Code logo 按钮
 
 - **状态**: `[x]` DONE。覆盖率 90.6/81.48/88.71/92.71(≥80×4)· 双 typecheck 干净 · `build:web` OK · 真浏览器 + 真 VS Code 端到端验证通过。
diff --git a/public/projects.ts b/public/projects.ts
index 8bf2857..4a2226c 100644
--- a/public/projects.ts
+++ b/public/projects.ts
@@ -13,8 +13,14 @@
  * stopped + cleaned up on hide.
  */
 
-import type { ProjectInfo, ProjectSessionRef, ClaudeStatus } from '../src/types.js'
-import { el, relTime } from './preview-grid.js'
+import type {
+  ProjectInfo,
+  ProjectSessionRef,
+  ClaudeStatus,
+  ProjectDetail,
+  WorktreeInfo,
+} from '../src/types.js'
+import { el, relTime, statusText } from './preview-grid.js'
 import { CLAUDE_LOGO, CODEX_LOGO, VSCODE_LOGO } from './icons.js'
 
 /* ── Constants ───────────────────────────────────────────────────────────── */
@@ -137,6 +143,26 @@ async function fetchProjects(): Promise<ProjectInfo[]> {
   }
 }
 
+/** Fetch one project's detail (branch/worktrees + sessions). null on any error. */
+async function fetchProjectDetail(projectPath: string): Promise<ProjectDetail | null> {
+  try {
+    const res = await fetch(`/projects/detail?path=${encodeURIComponent(projectPath)}`)
+    if (!res.ok) return null
+    return (await res.json()) as ProjectDetail
+  } catch {
+    return null
+  }
+}
+
+/** Kill a running session (manage-page DELETE; same-origin → Origin guard passes). */
+async function killSession(id: string): Promise<void> {
+  try {
+    await fetch(`/live-sessions/${encodeURIComponent(id)}`, { method: 'DELETE' })
+  } catch {
+    // best-effort — the refresh that follows will reflect the real state
+  }
+}
+
 /* ── Status helpers ──────────────────────────────────────────────────────── */
 
 function sessionDotClass(status: ClaudeStatus): string {
@@ -256,6 +282,7 @@ export function makeProjectCard(
   favs: ReadonlySet<string>,
   hooks: ProjectsHooks,
   onToggleFav: (path: string) => void,
+  onOpenDetail?: (path: string) => void,
 ): HTMLElement {
   const card = el('div', 'proj-card')
 
@@ -272,6 +299,19 @@ export function makeProjectCard(
   })
 
   const name = el('span', 'proj-name', project.name)
+  if (onOpenDetail) {
+    name.classList.add('proj-name-link')
+    name.setAttribute('role', 'button')
+    name.tabIndex = 0
+    name.title = `View ${project.name} details`
+    name.addEventListener('click', () => onOpenDetail(project.path))
+    name.addEventListener('keydown', (e) => {
+      if (e.key === 'Enter' || e.key === ' ') {
+        e.preventDefault()
+        onOpenDetail(project.path)
+      }
+    })
+  }
 
   header.append(favBtn, name)
 
@@ -310,6 +350,112 @@ export function makeProjectCard(
   return card
 }
 
+/* ── Detail view (branch / worktrees + active sessions) ─────────────────────── */
+
+/** One worktree row: branch (or detached@head) + main/current/locked tags + path. */
+function makeWorktreeRow(wt: WorktreeInfo): HTMLElement {
+  const row = el('div', 'proj-wt-row')
+  const label = wt.branch ?? (wt.head ? `detached @ ${wt.head}` : 'detached')
+  row.append(el('span', 'proj-wt-branch', label))
+  if (wt.isMain) row.append(el('span', 'proj-wt-tag', 'main'))
+  if (wt.isCurrent) row.append(el('span', 'proj-wt-tag proj-wt-tag-current', 'current'))
+  if (wt.locked) row.append(el('span', 'proj-wt-tag', 'locked'))
+  if (wt.prunable) row.append(el('span', 'proj-wt-tag', 'prunable'))
+  row.append(el('span', 'proj-wt-path', wt.path))
+  return row
+}
+
+/** One detailed session row: status + title + metadata + Open / Kill actions. */
+function makeDetailSessionRow(
+  s: ProjectSessionRef,
+  onEnter: (id: string) => void,
+  onKill: (id: string) => void,
+): HTMLElement {
+  const row = el('div', 'proj-dsession')
+  const dot = el('span', sessionDotClass(s.status))
+  const main = el('div', 'proj-dsession-main')
+  main.append(el('span', 'proj-dsession-title', s.title ?? 'session'))
+  const parts: string[] = []
+  if (s.status !== 'unknown') parts.push(statusText(s.status))
+  parts.push(`👁 ${s.clientCount}`)
+  parts.push(`started ${relTime(s.createdAt)} ago`)
+  main.append(el('span', 'proj-dsession-meta', parts.join(' · ')))
+  const open = el('button', 'proj-dsession-open', 'Open')
+  open.addEventListener('click', () => onEnter(s.id))
+  const kill = el('button', 'proj-dsession-kill', '✕')
+  kill.title = 'Kill this session'
+  kill.setAttribute('aria-label', 'Kill session')
+  kill.addEventListener('click', () => onKill(s.id))
+  row.append(dot, main, open, kill)
+  return row
+}
+
+interface DetailCallbacks {
+  onBack: () => void
+  onKill: (id: string) => void
+}
+
+/** Render the project detail view (exported for unit tests). */
+export function renderProjectDetail(
+  detail: ProjectDetail | null,
+  hooks: ProjectsHooks,
+  cb: DetailCallbacks,
+): HTMLElement {
+  const root = el('div', 'proj-detail-inner')
+
+  const back = el('button', 'proj-back', '← All projects')
+  back.addEventListener('click', () => cb.onBack())
+  root.append(back)
+
+  if (detail === null) {
+    root.append(el('div', 'proj-empty', 'Project not found.'))
+    return root
+  }
+
+  // Header: name + branch + dirty + path
+  const head = el('div', 'proj-detail-head')
+  head.append(el('h2', 'proj-detail-name', detail.name))
+  if (detail.branch) head.append(el('span', 'proj-branch', detail.branch))
+  if (detail.dirty === true) {
+    const d = el('span', 'proj-dirty', '●')
+    d.title = 'Uncommitted changes'
+    head.append(d)
+  }
+  root.append(head)
+  root.append(el('div', 'proj-detail-path', detail.path))
+
+  // Branch / worktrees
+  root.append(el('div', 'proj-section-title', detail.worktrees.length > 1 ? 'Worktrees' : 'Branch'))
+  if (!detail.isGit) {
+    root.append(el('div', 'proj-empty', 'Not a git repository.'))
+  } else if (detail.worktrees.length === 0) {
+    root.append(
+      el('div', 'proj-empty', detail.branch ? `On branch ${detail.branch}` : 'No worktree info.'),
+    )
+  } else {
+    const list = el('div', 'proj-wt-list')
+    for (const wt of detail.worktrees) list.append(makeWorktreeRow(wt))
+    root.append(list)
+  }
+
+  // Active sessions
+  const running = detail.sessions.filter((s) => !s.exited)
+  root.append(el('div', 'proj-section-title', `Active sessions (${running.length})`))
+  if (running.length === 0) {
+    root.append(el('div', 'proj-empty', 'No running sessions — start one below.'))
+  } else {
+    const list = el('div', 'proj-detail-sessions')
+    for (const s of running) list.append(makeDetailSessionRow(s, hooks.onEnterSession, cb.onKill))
+    root.append(list)
+  }
+
+  // Launchers
+  root.append(el('div', 'proj-section-title', 'Start'))
+  root.append(makeLauncherRow(detail, hooks))
+
+  return root
+}
+
 /* ── Mount ───────────────────────────────────────────────────────────────── */
 
 export function mountProjects(host: HTMLElement, hooks: ProjectsHooks): ProjectsPanel {
@@ -330,9 +476,36 @@ export function mountProjects(host: HTMLElement, hooks: ProjectsHooks): Projects
   const grid = el('div', 'proj-grid')
   root.append(grid)
 
+  const detailEl = el('div', 'proj-detail')
+  detailEl.style.display = 'none'
+  root.append(detailEl)
+
   let allProjects: ProjectInfo[] = []
   let favs: Set<string> = getFavs()
   let timer: ReturnType<typeof setInterval> | null = null
+  let view: 'grid' | 'detail' = 'grid'
+  let detailPath: string | null = null
+
+  function applyView(): void {
+    const isGrid = view === 'grid'
+    searchWrap.style.display = isGrid ? '' : 'none'
+    grid.style.display = isGrid ? '' : 'none'
+    detailEl.style.display = isGrid ? 'none' : 'block'
+  }
+
+  function openDetail(p: string): void {
+    view = 'detail'
+    detailPath = p
+    applyView()
+    void refresh()
+  }
+
+  function closeDetail(): void {
+    view = 'grid'
+    detailPath = null
+    applyView()
+    void refresh()
+  }
 
   function renderGrid(): void {
     const filtered = filterProjects(allProjects, searchInput.value)
@@ -351,16 +524,39 @@ export function mountProjects(host: HTMLElement, hooks: ProjectsHooks): Projects
 
     for (const p of sorted) {
       grid.append(
-        makeProjectCard(p, favs, hooks, (path) => {
-          favs = toggleFav(favs, path)
-          saveFavs(favs)
-          renderGrid()
-        }),
+        makeProjectCard(
+          p,
+          favs,
+          hooks,
+          (path) => {
+            favs = toggleFav(favs, path)
+            saveFavs(favs)
+            renderGrid()
+          },
+          openDetail,
+        ),
       )
     }
   }
 
+  function renderDetail(detail: ProjectDetail | null): void {
+    detailEl.replaceChildren(
+      renderProjectDetail(detail, hooks, {
+        onBack: closeDetail,
+        onKill: (id) => {
+          void killSession(id).then(() => {
+            if (view === 'detail') void refresh()
+          })
+        },
+      }),
+    )
+  }
+
   async function refresh(): Promise<void> {
+    if (view === 'detail' && detailPath !== null) {
+      renderDetail(await fetchProjectDetail(detailPath))
+      return
+    }
     allProjects = await fetchProjects()
     favs = getFavs()
     renderGrid()
@@ -372,6 +568,10 @@ export function mountProjects(host: HTMLElement, hooks: ProjectsHooks): Projects
     setVisible(v: boolean): void {
       root.style.display = v ? 'block' : 'none'
       if (v) {
+        // Re-entering the chooser always lands on the grid (never a stale detail).
+        view = 'grid'
+        detailPath = null
+        applyView()
         void refresh()
         if (timer === null) {
           timer = setInterval(() => {
diff --git a/public/style.css b/public/style.css
index 24403c9..ced0b78 100644
--- a/public/style.css
+++ b/public/style.css
@@ -1156,6 +1156,160 @@ body {
   text-align: center;
 }
 
+/* ── Project detail view ─────────────────────────────────────────── */
+.proj-name-link {
+  cursor: pointer;
+}
+.proj-name-link:hover {
+  text-decoration: underline;
+  text-underline-offset: 2px;
+}
+.proj-detail-inner {
+  max-width: 900px;
+  margin: 0 auto;
+}
+.proj-back {
+  background: none;
+  border: 1px solid var(--border);
+  color: var(--text-dim);
+  border-radius: 8px;
+  padding: 6px 12px;
+  font: inherit;
+  font-size: 13px;
+  cursor: pointer;
+  margin-bottom: 16px;
+  transition: background 0.12s ease, color 0.12s ease;
+}
+.proj-back:hover {
+  background: var(--surface-2);
+  color: var(--text);
+}
+.proj-detail-head {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  flex-wrap: wrap;
+}
+.proj-detail-name {
+  margin: 0;
+  font-size: 22px;
+  font-weight: 700;
+  color: #fff;
+}
+.proj-detail-path {
+  margin: 4px 0 8px;
+  font-family: Menlo, Consolas, monospace;
+  font-size: 12px;
+  color: var(--text-faint);
+  word-break: break-all;
+}
+.proj-section-title {
+  margin: 22px 0 10px;
+  font-size: 12px;
+  font-weight: 700;
+  letter-spacing: 0.06em;
+  text-transform: uppercase;
+  color: var(--text-faint);
+}
+/* Worktrees */
+.proj-wt-list {
+  display: flex;
+  flex-direction: column;
+  gap: 6px;
+}
+.proj-wt-row {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  padding: 9px 12px;
+  background: var(--surface-2);
+  border: 1px solid var(--border);
+  border-radius: 8px;
+}
+.proj-wt-branch {
+  font-weight: 600;
+  color: var(--text);
+}
+.proj-wt-tag {
+  font-size: 10px;
+  font-weight: 700;
+  text-transform: uppercase;
+  letter-spacing: 0.04em;
+  padding: 2px 7px;
+  border-radius: 999px;
+  background: var(--surface-3);
+  color: var(--text-dim);
+}
+.proj-wt-tag-current {
+  background: var(--accent);
+  color: var(--on-accent);
+}
+.proj-wt-path {
+  margin-left: auto;
+  font-family: Menlo, Consolas, monospace;
+  font-size: 11px;
+  color: var(--text-faint);
+  word-break: break-all;
+}
+/* Detailed session rows */
+.proj-detail-sessions {
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+}
+.proj-dsession {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  padding: 10px 12px;
+  background: var(--surface-2);
+  border: 1px solid var(--border);
+  border-radius: 8px;
+}
+.proj-dsession-main {
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+  min-width: 0;
+  flex: 1;
+}
+.proj-dsession-title {
+  font-weight: 600;
+  color: var(--text);
+}
+.proj-dsession-meta {
+  font-size: 12px;
+  color: var(--text-dim);
+}
+.proj-dsession-open {
+  background: var(--accent);
+  color: var(--on-accent);
+  border: none;
+  border-radius: 7px;
+  padding: 6px 14px;
+  font: inherit;
+  font-weight: 600;
+  cursor: pointer;
+}
+.proj-dsession-open:hover {
+  background: var(--accent-2);
+}
+.proj-dsession-kill {
+  background: none;
+  border: 1px solid var(--border);
+  color: var(--text-dim);
+  border-radius: 7px;
+  width: 30px;
+  height: 30px;
+  cursor: pointer;
+  font-size: 14px;
+}
+.proj-dsession-kill:hover {
+  background: var(--red, #e5484d);
+  border-color: var(--red, #e5484d);
+  color: #fff;
+}
+
 /* Empty state */
 .proj-empty {
   color: var(--text-dim);
diff --git a/src/http/projects.ts b/src/http/projects.ts
index f78ec40..53ab01d 100644
--- a/src/http/projects.ts
+++ b/src/http/projects.ts
@@ -19,8 +19,15 @@ import path from 'node:path'
 import { execFile } from 'node:child_process'
 import { promisify } from 'node:util'
 import type { Dirent } from 'node:fs'
-import type { Config, LiveSessionInfo, ProjectInfo, ProjectSessionRef } from '../types.js'
+import type {
+  Config,
+  LiveSessionInfo,
+  ProjectInfo,
+  ProjectSessionRef,
+  ProjectDetail,
+} from '../types.js'
 import { listSessions } from './history.js'
+import { listWorktrees } from './worktrees.js'
 
 const execFileAsync = promisify(execFile)
 
@@ -353,3 +360,42 @@ export async function buildProjects(
   }))
   return sortProjects(withSessions).slice(0, MAX_PROJECTS)
 }
+
+/**
+ * Detail for one project: branch + dirty + worktrees + its running sessions.
+ * `projectPath` must be an absolute, existing directory (else null — 404). Not
+ * cached: the detail view is opened on demand and wants fresh worktree/session
+ * state. Reads only (git branch/status/worktree-list); never throws.
+ */
+export async function buildProjectDetail(
+  cfg: Config,
+  projectPath: string,
+  liveSessions: readonly LiveSessionInfo[],
+): Promise<ProjectDetail | null> {
+  if (typeof projectPath !== 'string' || !path.isAbsolute(projectPath)) return null
+
+  let stat
+  try {
+    stat = await fs.stat(projectPath)
+  } catch {
+    return null
+  }
+  if (!stat.isDirectory()) return null
+
+  const isGit = await hasGitEntry(projectPath)
+  const [branch, dirty, worktrees] = await Promise.all([
+    isGit ? readBranch(projectPath) : Promise.resolve(undefined),
+    isGit && cfg.projectDirtyCheck ? readDirty(projectPath) : Promise.resolve(undefined),
+    isGit ? listWorktrees(projectPath) : Promise.resolve([]),
+  ])
+
+  return {
+    name: path.basename(projectPath),
+    path: projectPath,
+    isGit,
+    branch,
+    dirty,
+    worktrees,
+    sessions: matchSessions(projectPath, liveSessions),
+  }
+}
diff --git a/src/http/worktrees.ts b/src/http/worktrees.ts
new file mode 100644
index 0000000..a3f4798
--- /dev/null
+++ b/src/http/worktrees.ts
@@ -0,0 +1,73 @@
+/**
+ * src/http/worktrees.ts (v0.6 project detail) — list a repo's git worktrees.
+ *
+ * `git worktree list --porcelain` emits blank-line-separated records; the first
+ * record is the main worktree. Best-effort: a non-repo / git error yields [].
+ */
+
+import { execFile } from 'node:child_process'
+import { promisify } from 'node:util'
+import type { WorktreeInfo } from '../types.js'
+
+const execFileAsync = promisify(execFile)
+
+const WORKTREE_TIMEOUT_MS = 2000
+const WORKTREE_MAX_BUFFER = 1024 * 1024
+
+/**
+ * Parse `git worktree list --porcelain`. `currentPath` flags which worktree is
+ * the requested project (isCurrent). The first record is the main worktree.
+ * Pure + unit-tested.
+ */
+export function parseWorktrees(porcelain: string, currentPath: string): WorktreeInfo[] {
+  const out: WorktreeInfo[] = []
+  let cur: { path?: string; branch?: string; head?: string; locked?: boolean; prunable?: boolean } = {}
+
+  const flush = (): void => {
+    if (cur.path === undefined) return
+    out.push({
+      path: cur.path,
+      branch: cur.branch,
+      head: cur.head,
+      isMain: out.length === 0, // git lists the main worktree first
+      isCurrent: cur.path === currentPath,
+      locked: cur.locked,
+      prunable: cur.prunable,
+    })
+    cur = {}
+  }
+
+  for (const raw of porcelain.split('\n')) {
+    const line = raw.trimEnd()
+    if (line === '') {
+      flush()
+      continue
+    }
+    const sep = line.indexOf(' ')
+    const key = sep === -1 ? line : line.slice(0, sep)
+    const val = sep === -1 ? '' : line.slice(sep + 1)
+    if (key === 'worktree') cur.path = val
+    else if (key === 'HEAD') cur.head = val.slice(0, 8)
+    else if (key === 'branch') cur.branch = val.replace(/^refs\/heads\//, '')
+    else if (key === 'detached') cur.branch = undefined
+    else if (key === 'locked') cur.locked = true
+    else if (key === 'prunable') cur.prunable = true
+  }
+  flush() // final record has no trailing blank line
+
+  return out
+}
+
+/** List worktrees for a repo (execFile, no shell); [] on any error/non-repo. */
+export async function listWorktrees(repoPath: string): Promise<WorktreeInfo[]> {
+  try {
+    const { stdout } = await execFileAsync('git', ['worktree', 'list', '--porcelain'], {
+      cwd: repoPath,
+      timeout: WORKTREE_TIMEOUT_MS,
+      maxBuffer: WORKTREE_MAX_BUFFER,
+    })
+    return parseWorktrees(stdout, repoPath)
+  } catch {
+    return []
+  }
+}
diff --git a/src/server.ts b/src/server.ts
index 9e299a6..c4defd9 100644
--- a/src/server.ts
+++ b/src/server.ts
@@ -39,7 +39,7 @@ import { parseClientMessage, serialize } from './protocol.js'
 import { isOriginAllowed } from './http/origin.js'
 import { parseHookEvent } from './http/hook.js'
 import { listSessions } from './http/history.js'
-import { buildProjects } from './http/projects.js'
+import { buildProjects, buildProjectDetail } from './http/projects.js'
 import { openInEditor } from './http/editor.js'
 import { createSessionManager } from './session/manager.js'
 import { detachWs, writeInput, setClientDims } from './session/session.js'
@@ -170,6 +170,28 @@ export function startServer(cfg: Config): { close(): Promise<void> } {
     }
   })
 
+  // Project detail (v0.6) — branch/worktrees + running sessions for one repo.
+  // Read-only (git branch/status/worktree-list); same threat model as /projects.
+  // ?path must be an absolute existing directory (validated in buildProjectDetail).
+  app.get('/projects/detail', async (req, res) => {
+    const target = req.query['path']
+    if (typeof target !== 'string' || target === '') {
+      res.status(400).json({ error: 'path query parameter is required' })
+      return
+    }
+    try {
+      const detail = await buildProjectDetail(cfg, target, manager.list())
+      if (detail === null) {
+        res.status(404).json({ error: 'project not found' })
+        return
+      }
+      res.json(detail)
+    } catch (err) {
+      console.error('[server] /projects/detail failed:', err instanceof Error ? err.message : String(err))
+      res.status(500).json({ error: 'failed to read project detail' })
+    }
+  })
+
   // Preview (v0.4 manage page) — the tail of a session's scrollback so the grid
   // can render a live read-only thumbnail of its current screen. No client/attach.
   app.get('/live-sessions/:id/preview', (req, res) => {
diff --git a/src/types.ts b/src/types.ts
index ecaa976..0e4cd86 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -223,6 +223,29 @@ export interface ProjectInfo {
   sessions: ProjectSessionRef[]; // running sessions in this project (1:N; may be empty)
 }
 
+/** One entry from `git worktree list --porcelain` (project detail view). */
+export interface WorktreeInfo {
+  path: string; // worktree absolute path
+  branch?: string; // branch name (refs/heads/x → x); undefined when detached
+  head?: string; // short HEAD sha
+  isMain: boolean; // the repo's primary worktree (listed first)
+  isCurrent: boolean; // this worktree is the requested project path
+  locked?: boolean; // `git worktree lock`ed
+  prunable?: boolean; // git considers it prunable (gone working tree)
+}
+
+/** Detailed view of one project: branch/worktrees + its running sessions.
+ *  impl: src/http/projects.ts buildProjectDetail(cfg, path, liveSessions). */
+export interface ProjectDetail {
+  name: string;
+  path: string;
+  isGit: boolean;
+  branch?: string;
+  dirty?: boolean;
+  worktrees: WorktreeInfo[]; // empty for a non-git dir
+  sessions: ProjectSessionRef[]; // running sessions under this path (fresh)
+}
+
 export interface SessionManager {
   handleAttach(
     ws: WebSocketLike,
diff --git a/test/projects-panel.test.ts b/test/projects-panel.test.ts
index d532990..cdc1285 100644
--- a/test/projects-panel.test.ts
+++ b/test/projects-panel.test.ts
@@ -21,8 +21,16 @@ class FakeTerminal {
 vi.mock('@xterm/xterm', () => ({ Terminal: FakeTerminal }))
 
 // Dynamic import AFTER mock declaration so the factory is in place.
-const { filterProjects, sortProjects, getFavs, saveFavs, toggleFav, normalizeProject, makeProjectCard } =
-  await import('../public/projects.js')
+const {
+  filterProjects,
+  sortProjects,
+  getFavs,
+  saveFavs,
+  toggleFav,
+  normalizeProject,
+  makeProjectCard,
+  renderProjectDetail,
+} = await import('../public/projects.js')
 
 /* ── Helpers ───────────────────────────────────────────────────────────────── */
 
@@ -352,4 +360,109 @@ describe('makeProjectCard — launcher row', () => {
     const card = makeProjectCard(p, new Set(), noopHooks(), () => {})
     expect(card.querySelector('.proj-launch-claude .proj-launch-badge')?.textContent).toBe('2')
   })
+
+  it('makes the name a detail link only when onOpenDetail is given', () => {
+    const onOpenDetail = vi.fn()
+    const card = makeProjectCard(makeProject({ path: '/p/r' }), new Set(), noopHooks(), () => {}, onOpenDetail)
+    const name = card.querySelector('.proj-name') as HTMLElement
+    expect(name.classList.contains('proj-name-link')).toBe(true)
+    name.click()
+    expect(onOpenDetail).toHaveBeenCalledWith('/p/r')
+
+    const plain = makeProjectCard(makeProject(), new Set(), noopHooks(), () => {})
+    expect(plain.querySelector('.proj-name')!.classList.contains('proj-name-link')).toBe(false)
+  })
+})
+
+/* ── renderProjectDetail (branch/worktrees + active sessions) ───────────────── */
+
+describe('renderProjectDetail', () => {
+  const hooks = () => ({ onOpenProject: vi.fn(), onEnterSession: vi.fn() })
+  const cbs = () => ({ onBack: vi.fn(), onKill: vi.fn() })
+
+  function detail(over: Partial<import('../src/types.js').ProjectDetail> = {}) {
+    return {
+      name: 'repo',
+      path: '/p/repo',
+      isGit: true,
+      branch: 'main',
+      worktrees: [],
+      sessions: [],
+      ...over,
+    }
+  }
+
+  it('renders "Project not found" + working Back for a null detail', () => {
+    const cb = cbs()
+    const root = renderProjectDetail(null, hooks(), cb)
+    expect(root.textContent).toContain('Project not found')
+    ;(root.querySelector('.proj-back') as HTMLButtonElement).click()
+    expect(cb.onBack).toHaveBeenCalled()
+  })
+
+  it('shows the header name, path, and branch', () => {
+    const root = renderProjectDetail(detail(), hooks(), cbs())
+    expect(root.querySelector('.proj-detail-name')?.textContent).toBe('repo')
+    expect(root.querySelector('.proj-detail-path')?.textContent).toBe('/p/repo')
+    expect(root.querySelector('.proj-branch')?.textContent).toBe('main')
+  })
+
+  it('lists worktrees with branch, tags, and path', () => {
+    const root = renderProjectDetail(
+      detail({
+        worktrees: [
+          { path: '/p/repo', branch: 'main', head: 'abc12345', isMain: true, isCurrent: true },
+          { path: '/p/wt/feat', branch: 'feature/x', head: 'def67890', isMain: false, isCurrent: false },
+        ],
+      }),
+      hooks(),
+      cbs(),
+    )
+    const rows = root.querySelectorAll('.proj-wt-row')
+    expect(rows).toHaveLength(2)
+    expect(rows[0]?.querySelector('.proj-wt-branch')?.textContent).toBe('main')
+    expect(rows[0]?.querySelector('.proj-wt-tag-current')).not.toBeNull()
+    expect(rows[1]?.querySelector('.proj-wt-branch')?.textContent).toBe('feature/x')
+  })
+
+  it('renders detached worktrees as "detached @ head"', () => {
+    const root = renderProjectDetail(
+      detail({ worktrees: [{ path: '/p/repo', head: 'deadbeef', isMain: true, isCurrent: true }] }),
+      hooks(),
+      cbs(),
+    )
+    expect(root.querySelector('.proj-wt-branch')?.textContent).toBe('detached @ deadbeef')
+  })
+
+  it('lists active sessions with Open + Kill wired, ignoring exited ones', () => {
+    const h = hooks()
+    const cb = cbs()
+    const root = renderProjectDetail(
+      detail({
+        sessions: [
+          { id: 's1', title: 'claude', status: 'working', clientCount: 2, createdAt: 1, exited: false },
+          { id: 'gone', status: 'idle', clientCount: 0, createdAt: 1, exited: true },
+        ],
+      }),
+      h,
+      cb,
+    )
+    const rows = root.querySelectorAll('.proj-dsession')
+    expect(rows).toHaveLength(1)
+    ;(rows[0]!.querySelector('.proj-dsession-open') as HTMLButtonElement).click()
+    expect(h.onEnterSession).toHaveBeenCalledWith('s1')
+    ;(rows[0]!.querySelector('.proj-dsession-kill') as HTMLButtonElement).click()
+    expect(cb.onKill).toHaveBeenCalledWith('s1')
+  })
+
+  it('shows an empty-state when no sessions are running, plus the launcher row', () => {
+    const root = renderProjectDetail(detail(), hooks(), cbs())
+    expect(root.textContent).toContain('No running sessions')
+    expect(root.querySelectorAll('.proj-launch')).toHaveLength(3)
+  })
+
+  it('flags a non-git directory', () => {
+    const root = renderProjectDetail(detail({ isGit: false, branch: undefined }), hooks(), cbs())
+    expect(root.textContent).toContain('Not a git repository')
+  })
 })
diff --git a/test/projects.test.ts b/test/projects.test.ts
index 6cbed9b..fcf1113 100644
--- a/test/projects.test.ts
+++ b/test/projects.test.ts
@@ -14,7 +14,9 @@ vi.mock('../src/http/history.js', () => ({
   listSessions: (...a: unknown[]) => mockListSessions(...a),
 }))
 
-const { parseGitHead, buildProjects, _clearProjectCache } = await import('../src/http/projects.js')
+const { parseGitHead, buildProjects, buildProjectDetail, _clearProjectCache } = await import(
+  '../src/http/projects.js'
+)
 
 const execFileP = promisify(execFile)
 
@@ -347,3 +349,73 @@ describe('buildProjects — dirty check', () => {
     expect(out.find((p) => p.name === 'repoA')!.dirty).toBeUndefined()
   })
 })
+
+// ── buildProjectDetail ───────────────────────────────────────────────────────────
+
+describe('buildProjectDetail', () => {
+  it('returns null for a relative path', async () => {
+    expect(await buildProjectDetail(makeCfg({}), 'relative/dir', [])).toBeNull()
+  })
+
+  it('returns null for a non-existent path', async () => {
+    expect(await buildProjectDetail(makeCfg({}), path.join(tmp, 'nope'), [])).toBeNull()
+  })
+
+  it('returns null when the path is a file', async () => {
+    const f = path.join(tmp, 'file.txt')
+    await fs.writeFile(f, 'x')
+    expect(await buildProjectDetail(makeCfg({}), f, [])).toBeNull()
+  })
+
+  it('reports a non-git directory with no worktrees', async () => {
+    const dir = path.join(tmp, 'plain')
+    await fs.mkdir(dir)
+    const d = await buildProjectDetail(makeCfg({}), dir, [])
+    expect(d).not.toBeNull()
+    expect(d!.isGit).toBe(false)
+    expect(d!.worktrees).toEqual([])
+    expect(d!.name).toBe('plain')
+  })
+
+  it('reads the branch for a git repo (worktrees best-effort)', async () => {
+    const dir = path.join(tmp, 'repo')
+    await makeRepo(dir, 'develop')
+    const d = await buildProjectDetail(makeCfg({}), dir, [])
+    expect(d!.isGit).toBe(true)
+    expect(d!.branch).toBe('develop')
+    expect(Array.isArray(d!.worktrees)).toBe(true) // real `git` fails on the fake .git → []
+  })
+
+  it('merges running sessions whose cwd is the project or under it', async () => {
+    const dir = path.join(tmp, 'repo')
+    await fs.mkdir(dir)
+    const live = [
+      makeLive({ id: 'a', cwd: dir, status: 'working' }),
+      makeLive({ id: 'b', cwd: path.join(dir, 'sub') }),
+      makeLive({ id: 'c', cwd: path.join(tmp, 'other') }),
+    ]
+    const d = await buildProjectDetail(makeCfg({}), dir, live)
+    expect(d!.sessions.map((s) => s.id).sort()).toEqual(['a', 'b'])
+  })
+
+  it('lists worktrees for a real git repo (gated on git)', async () => {
+    if (!(await gitAvailable())) return
+    await fs.mkdir(path.join(tmp, 'realrepo'))
+    // git canonicalises paths (/var → /private/var on macOS), so pass the
+    // realpath — real project paths from discovery are already canonical.
+    const dir = await fs.realpath(path.join(tmp, 'realrepo'))
+    await execFileP('git', ['init', '-q', '-b', 'main'], { cwd: dir })
+    await execFileP('git', ['config', 'user.email', 't@t'], { cwd: dir })
+    await execFileP('git', ['config', 'user.name', 't'], { cwd: dir })
+    await fs.writeFile(path.join(dir, 'f.txt'), 'hi')
+    await execFileP('git', ['add', '.'], { cwd: dir })
+    await execFileP('git', ['commit', '-q', '-m', 'init'], { cwd: dir })
+
+    const d = await buildProjectDetail(makeCfg({ projectDirtyCheck: true }), dir, [])
+    expect(d!.isGit).toBe(true)
+    expect(d!.branch).toBe('main')
+    expect(d!.worktrees.length).toBeGreaterThanOrEqual(1)
+    expect(d!.worktrees[0]).toMatchObject({ isMain: true, isCurrent: true, branch: 'main' })
+    expect(d!.dirty).toBe(false)
+  })
+})
diff --git a/test/worktrees.test.ts b/test/worktrees.test.ts
new file mode 100644
index 0000000..092116f
--- /dev/null
+++ b/test/worktrees.test.ts
@@ -0,0 +1,83 @@
+/**
+ * test/worktrees.test.ts — parseWorktrees (pure parser for `git worktree list
+ * --porcelain`). The git wrapper itself is covered via the projects-detail
+ * integration test in projects.test.ts.
+ */
+
+import { describe, it, expect } from 'vitest'
+import { parseWorktrees } from '../src/http/worktrees.js'
+
+const MAIN = [
+  'worktree /repo/main',
+  'HEAD 1234567890abcdef1234567890abcdef12345678',
+  'branch refs/heads/main',
+  '',
+].join('\n')
+
+describe('parseWorktrees', () => {
+  it('parses a single main worktree on a branch', () => {
+    const wts = parseWorktrees(MAIN, '/repo/main')
+    expect(wts).toHaveLength(1)
+    expect(wts[0]).toMatchObject({
+      path: '/repo/main',
+      branch: 'main',
+      head: '12345678', // first 8 of the sha
+      isMain: true,
+      isCurrent: true,
+    })
+  })
+
+  it('marks only the first record as main; flags the current path', () => {
+    const text = [
+      'worktree /repo/main',
+      'HEAD aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa',
+      'branch refs/heads/main',
+      '',
+      'worktree /repo/wt/feature',
+      'HEAD bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb',
+      'branch refs/heads/feature/login',
+      '',
+    ].join('\n')
+    const wts = parseWorktrees(text, '/repo/wt/feature')
+    expect(wts).toHaveLength(2)
+    expect(wts[0]).toMatchObject({ path: '/repo/main', branch: 'main', isMain: true, isCurrent: false })
+    expect(wts[1]).toMatchObject({
+      path: '/repo/wt/feature',
+      branch: 'feature/login', // refs/heads/ stripped, slashes kept
+      isMain: false,
+      isCurrent: true,
+    })
+  })
+
+  it('handles a detached HEAD (no branch)', () => {
+    const text = ['worktree /repo/x', 'HEAD cccccccccccccccccccccccccccccccccccccccc', 'detached', ''].join('\n')
+    const wts = parseWorktrees(text, '/other')
+    expect(wts[0]?.branch).toBeUndefined()
+    expect(wts[0]?.head).toBe('cccccccc')
+  })
+
+  it('captures locked and prunable flags', () => {
+    const text = [
+      'worktree /repo/locked',
+      'HEAD dddddddddddddddddddddddddddddddddddddddd',
+      'branch refs/heads/wip',
+      'locked',
+      'prunable gitdir file points to non-existent location',
+      '',
+    ].join('\n')
+    const wts = parseWorktrees(text, '/x')
+    expect(wts[0]?.locked).toBe(true)
+    expect(wts[0]?.prunable).toBe(true)
+  })
+
+  it('parses the final record even without a trailing blank line', () => {
+    const text = ['worktree /repo/main', 'HEAD eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee', 'branch refs/heads/main'].join(
+      '\n',
+    )
+    expect(parseWorktrees(text, '/repo/main')).toHaveLength(1)
+  })
+
+  it('returns [] for empty input', () => {
+    expect(parseWorktrees('', '/x')).toEqual([])
+  })
+})