diff --git a/INSTALL.md b/INSTALL.md
index aa472e87..c804eab3 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -86,6 +86,54 @@ Detaching is `Ctrl-b d` — it leaves the run alive, which is the whole point:
 the browser terminal and your local terminal are two clients on one pane, and
 restarting the dashboard never stops a run.
 
+### macOS
+
+Status: **code-audited, untested on a Mac.** The Mac-specific paths below are
+covered by Linux-side unit tests only; the checklist at the end of this section
+is what a Mac user runs to confirm them.
+
+```bash
+brew install node git tmux       # Node >= 22.5 for the plugin install (nvm works too)
+echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.zshrc   # where the plugin puts `agenthub`
+```
+
+- **Node:** a plugin install needs **>= 22.5** (it stores data through
+  `node:sqlite`); a checkout still runs on Node 20. The `agenthub` launcher
+  pins the node that installed it and falls back to `node` on `PATH` when a
+  `brew upgrade` or `nvm` switch deletes that binary.
+- **No systemd, so no auto-start on boot.** The server is a detached process
+  that runs until logout or reboot. It comes back at the next Claude Code
+  session start (within about 10 s), or by hand with `agenthub start`. A
+  discovery entry left over from before the reboot is ignored, so a recycled
+  pid can never pass for a live dashboard.
+- **Started from a Claude Code session.** The server drops the variables that
+  describe that session (`CLAUDECODE`, `CLAUDE_CODE_SESSION_ID`,
+  `CLAUDE_PLUGIN_ROOT`, …) before anything else runs, so lane panes do not
+  inherit them. Your own configuration (`CLAUDE_CONFIG_DIR`,
+  `CLAUDE_CODE_USE_BEDROCK`, `ANTHROPIC_*`) passes through. A tmux server that
+  an older build started keeps its dirty global env until it exits
+  (`tmux kill-server` once, with no run you care about open).
+- **Paths.** A lane's directory is stored by its real path, so a typed `/tmp/x`
+  becomes `/private/tmp/x` and a differently-cased path on a case-insensitive
+  volume becomes the one on disk — that is what sessions report, so they bind.
+  Lanes created before this change keep the string they were created with.
+- **Account switching** uses the login Keychain item `Claude Code-credentials`;
+  macOS may ask once for permission the first time.
+- **Option key** in the browser terminal types special characters (it is not
+  sent as Meta).
+
+**Mac checklist** — please run it and report the result on issue #22:
+
+1. Fresh plugin install from a Terminal `claude` session: `/agenthub-doctor` is all OK (the systemd row says not available) and the dashboard answers on `http://localhost:4820`.
+2. `tmux show-environment -g | grep -i claude` prints nothing.
+3. Add a Repo lane by typing its path in a different case: sessions bind to it, and `agenthub stage plan` inside it moves the map.
+4. **Start Run** in the browser: the terminal attaches, typing works, an image paste into `claude` works, and `exit` returns to the run form.
+5. Changes panel: diff, stage and commit on a lane.
+6. Switch profile and check `claude /status` shows the new account. Repeat with a non-default `CLAUDE_HOME`, which also checks the Keychain service name.
+7. `brew upgrade node && brew cleanup`, then `agenthub status` still works.
+8. Reboot, open `claude`, and the dashboard comes back within about 10 s.
+9. `/agenthub-update` completes and the server restarts on the new version.
+
 ---
 
 ## Step 1 — Clone the repository
diff --git a/README.md b/README.md
index 6b2bff46..0910a82c 100644
--- a/README.md
+++ b/README.md
@@ -104,6 +104,12 @@ sudo pacman -S tmux          # Arch
 
 Windows has no native tmux — run AgentHub under WSL2 and install it there.
 
+macOS (code-audited, untested on a Mac): `brew install node git tmux` (Node
+>= 22.5 for the plugin), add `~/.local/bin` to `PATH` in `~/.zshrc`. There is
+no systemd, so the dashboard runs until logout/reboot and comes back at the
+next Claude Code session, or by hand with `agenthub start`. Details and a
+checklist to verify it: [INSTALL.md § macOS](INSTALL.md#macos).
+
 Verify, both from your shell and from the server's point of view:
 
 ```bash
diff --git a/README.vi.md b/README.vi.md
index 96e13fef..157cb0ba 100644
--- a/README.vi.md
+++ b/README.vi.md
@@ -92,6 +92,12 @@ sudo pacman -S tmux          # Arch
 
 Windows không có tmux native — chạy AgentHub trong WSL2 và cài tmux ở trong đó.
 
+macOS (đã rà soát code, chưa kiểm thử trên máy Mac): `brew install node git tmux`
+(Node >= 22.5 cho bản plugin), thêm `~/.local/bin` vào `PATH` trong `~/.zshrc`.
+Không có systemd, nên dashboard chạy đến khi đăng xuất/khởi động lại và tự lên
+lại ở phiên Claude Code kế tiếp, hoặc chạy tay bằng `agenthub start`. Chi tiết
+và checklist kiểm tra: [INSTALL.md § macOS](INSTALL.md#macos).
+
 Kiểm tra, cả từ shell của bạn lẫn từ góc nhìn của server:
 
 ```bash
diff --git a/docs/LANES.md b/docs/LANES.md
index fbc30046..6610ae9e 100644
--- a/docs/LANES.md
+++ b/docs/LANES.md
@@ -22,7 +22,7 @@ agenthub lanes add --cwd /path/to/repo --title "My Feature"
 
 The lane is now ready to track work. When you run a Claude Code session in that directory (or a subdirectory), the dashboard will bind the session to the lane automatically by matching the cwd.
 
-**Note:** The directory must exist and be an absolute path. A lane with a cwd of `/tmp/wt` will NOT capture `/tmp/wt-sibling` (no partial prefix match) but WILL capture sessions in `/tmp/wt/subdir/` (subdirectories are owned by the parent lane unless a deeper lane exists).
+**Note:** The directory must exist and be an absolute path. A lane with a cwd of `/tmp/wt` will NOT capture `/tmp/wt-sibling` (no partial prefix match) but WILL capture sessions in `/tmp/wt/subdir/` (subdirectories are owned by the parent lane unless a deeper lane exists). A `cwd` that exists is stored by its real path (`fs.realpathSync.native`), so `/tmp/wt` on macOS is stored as `/private/tmp/wt` and a differently-cased path on a case-insensitive volume as the spelling on disk — the path a session reports. A path that does not exist yet keeps the string it was given; rows created before this rule keep theirs.
 
 To provision a dashboard-managed git worktree instead of adopting an existing directory, use a source repository:
 
diff --git a/docs/PLUGINS.md b/docs/PLUGINS.md
index 75eee39e..53de674e 100644
--- a/docs/PLUGINS.md
+++ b/docs/PLUGINS.md
@@ -128,13 +128,13 @@ check.
 milliseconds — the real work happens in a detached worker, so a session never
 waits on an install:
 
-1. **Fast path** — recorded state matches this plugin build and a server is live → exit.
+1. **Fast path** — recorded state matches this plugin build and a server is live → exit. "Live" means a discovery entry whose pid answers AND whose `startedAt` is after this boot (60 s margin): an entry left over from before a reboot names a pid the OS may have handed to an unrelated process, and without systemd (macOS) nothing else clears it.
 2. **Superseded check** — if Claude Code records a DIFFERENT build of this plugin as installed, this one logs a line and does nothing else (see [A retired build never acts](#a-retired-build-never-acts)).
 3. **Node gate** — refuse below 22.5 with one line (see Prerequisites).
 4. **Lock** — atomic `mkdir` lock holding the PID; reclaimed when the owner is dead or the lock is older than 10 minutes, so two sessions cannot race the install or spawn two servers.
 5. **Install** — `npm install --omit=dev --ignore-scripts` into the runtime dir (never into the plugin cache, which is garbage-collected and replaced on every update). `--ignore-scripts` keeps the root `postinstall` from pulling the whole Vite client toolchain.
 6. **Legacy hook cleanup** — see above.
-7. **CLI** — write the `~/.local/bin/agenthub` launcher, never clobbering a `agenthub` the bootstrap did not write.
+7. **CLI** — write the `~/.local/bin/agenthub` launcher, never clobbering a `agenthub` the bootstrap did not write. It pins the node that ran the bootstrap and falls back to `node` on `PATH` when that binary is gone (a Homebrew Cellar or nvm path deleted by an upgrade).
 8. **UI build** — `client/` is copied into the runtime dir and built there (`npm ci --include=dev`, falling back to `npm install --include=dev`, then `npm run build`), landing in `runtime/client-dist` — the same directory the server serves from. `--include=dev` is required, not tidy: the entire build toolchain (`vite`, `typescript`, `@vitejs/plugin-react`, `tailwindcss`, `@types/*`) is a devDependency, and npm reads an inherited `NODE_ENV=production` as `--omit=dev`. Every bootstrap descended from the running server carries that env — the self-update chain, and any `SessionStart` fired by a `claude` inside a tmux pane the server started — so without the flag the install drops `vite` and the build dies on missing types. Skipped when a bundle for the current version already exists; a failure here does not fail the bootstrap (the API still works, and `/agenthub-open` can retry) but does mean `/run` 404s until it's fixed — and when a bundle from the PREVIOUS version is still on disk the failure is quieter still: the dashboard keeps serving the old UI against the new API, visible only as the Settings page's `UI build vX (rebuild client to match)` line.
 9. **Server** — on Linux with `systemd --user` available, install/refresh a
    `agenthub.service` unit (see [Auto-start on boot](#auto-start-on-boot)) instead
@@ -235,7 +235,13 @@ server falls back to the old per-session detached spawn instead.
 
 On macOS, Windows, or a Linux box without systemd, nothing changes: the
 server is a detached spawn started fresh on the next `SessionStart` after a
-reboot, same as always.
+reboot, same as always. That spawn inherits the Claude Code session's env, so
+`server/index.js` deletes the parent-session variables (`CLAUDECODE`,
+`CLAUDE_CODE_SESSION_ID`, `CLAUDE_CODE_MESSAGING_*`, `CLAUDE_PLUGIN_ROOT`, …)
+before anything else runs — otherwise tmux hands them to every lane pane. It is
+a denylist: user configuration such as `CLAUDE_CONFIG_DIR`,
+`CLAUDE_CODE_USE_BEDROCK` and `ANTHROPIC_*` passes through. There is no
+launchd agent; see [INSTALL.md § macOS](../INSTALL.md#macos).
 
 ### Who may stop the server
 
diff --git a/openapi.yaml b/openapi.yaml
index 73ddbbc9..3fa5a56e 100644
--- a/openapi.yaml
+++ b/openapi.yaml
@@ -10636,7 +10636,7 @@ paths:
       tags:
         - Lanes
       summary: Find or adopt the lane owning a working directory
-      description: 'Idempotent: returns the lane whose cwd is an exact match or the longest path-boundary parent of `cwd` with `created: false` (200) — with `exact: true` only an exact match counts, so a directory nested inside another lane gets a lane of its own (the Add-lane modal sends it) — otherwise creates an `adopted` lane and returns it with `created: true` (201). The Workspace page opens on a directory rather than a lane id, so this is how it gets exactly one lane for that directory. Concurrent calls for the same path resolve to ONE lane: the `lanes.cwd` UNIQUE constraint decides, and the loser re-reads and returns the winner''s lane.'
+      description: 'Idempotent: canonicalizes `cwd` to its real path when it exists (the same path `createLane` stores), then returns the lane whose cwd is an exact match or the longest path-boundary parent of `cwd` with `created: false` (200) — with `exact: true` only an exact match counts, so a directory nested inside another lane gets a lane of its own (the Add-lane modal sends it) — otherwise creates an `adopted` lane and returns it with `created: true` (201). The Workspace page opens on a directory rather than a lane id, so this is how it gets exactly one lane for that directory. Concurrent calls for the same path resolve to ONE lane: the `lanes.cwd` UNIQUE constraint decides, and the loser re-reads and returns the winner''s lane.'
       operationId: ensureLane
       requestBody:
         required: true
diff --git a/scripts/plugin-bootstrap.js b/scripts/plugin-bootstrap.js
index 36be1182..5c6d564d 100644
--- a/scripts/plugin-bootstrap.js
+++ b/scripts/plugin-bootstrap.js
@@ -359,13 +359,15 @@ function cliDir() {
  *
  * @returns {"written"|"exists"|"foreign"|"failed"}
  */
-function linkCli(dir = cliDir(), root = PLUGIN_ROOT) {
+function linkCli(dir = cliDir(), root = PLUGIN_ROOT, nodePath = process.execPath) {
   const marker = "# agenthub-plugin-launcher";
   const target = path.join(dir, process.platform === "win32" ? "agenthub.cmd" : "agenthub");
   const body =
     process.platform === "win32"
       ? `@rem agenthub-plugin-launcher\r\n@node "${path.join(root, "bin", "agenthub.js")}" %*\r\n`
-      : `#!/bin/sh\n${marker}\nexec "${process.execPath}" "${path.join(root, "bin", "agenthub.js")}" "$@"\n`;
+      : // The pinned node is a versioned path (Homebrew Cellar, nvm) that an
+        // upgrade deletes; fall back to whatever `node` PATH has then.
+        `#!/bin/sh\n${marker}\nN="${nodePath}"; [ -x "$N" ] || N=node\nexec "$N" "${path.join(root, "bin", "agenthub.js")}" "$@"\n`;
   try {
     if (fs.existsSync(target)) {
       const current = fs.readFileSync(target, "utf8");
@@ -419,7 +421,11 @@ function liveServers() {
   try {
     const parsed = JSON.parse(fs.readFileSync(getServerInfoPath(), "utf8"));
     const servers = Array.isArray(parsed.servers) ? parsed.servers : [parsed];
-    return servers.filter((s) => s && isPidAlive(s.pid));
+    // An entry older than this boot is a leftover whose pid may now belong to
+    // an unrelated process (macOS has no systemd to clean up after a reboot).
+    // 60 s margin for clock skew; an unparseable startedAt is kept.
+    const bootedAt = Date.now() - os.uptime() * 1000 - 60_000;
+    return servers.filter((s) => s && isPidAlive(s.pid) && !(Date.parse(s.startedAt) < bootedAt));
   } catch {
     return [];
   }
diff --git a/scripts/plugin-doctor.js b/scripts/plugin-doctor.js
index c51a2a09..a429460f 100644
--- a/scripts/plugin-doctor.js
+++ b/scripts/plugin-doctor.js
@@ -316,7 +316,9 @@ function cliStatus() {
     : [
         "warn",
         "agenthub CLI",
-        `${file} exists but ${dir} is not on PATH — add: export PATH="${dir}:$PATH"`,
+        `${file} exists but ${dir} is not on PATH — add${
+          process.platform === "darwin" ? " to ~/.zshrc" : ""
+        }: export PATH="${dir}:$PATH"`,
       ];
 }
 
diff --git a/server/__tests__/env-scrub.test.js b/server/__tests__/env-scrub.test.js
new file mode 100644
index 00000000..a53eda3c
--- /dev/null
+++ b/server/__tests__/env-scrub.test.js
@@ -0,0 +1,51 @@
+/**
+ * @file Tests that the server drops the variables describing the Claude Code
+ * session that started it (always the case on macOS, where there is no
+ * systemd unit to give it a clean env) — tmux and every lane pane inherit the
+ * server's env, so a leaked CLAUDECODE made each pane look like a nested
+ * session. User configuration (CLAUDE_CONFIG_DIR, ANTHROPIC_*, …) must survive.
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+
+const { it, after } = require("node:test");
+const assert = require("node:assert/strict");
+const fs = require("fs");
+const os = require("os");
+const path = require("path");
+
+const TMP = fs.mkdtempSync(path.join(os.tmpdir(), "agenthub-envscrub-"));
+process.env.DASHBOARD_DB_PATH = path.join(TMP, "dashboard.db");
+process.env.CLAUDE_HOME = path.join(TMP, "home");
+process.env.DASHBOARD_DATA_DIR = path.join(TMP, "data");
+
+process.env.CLAUDECODE = "1";
+process.env.CLAUDE_CODE_ENTRYPOINT = "cli";
+process.env.CLAUDE_CODE_SESSION_ID = "abc";
+process.env.CLAUDE_CODE_MESSAGING_SOCKET = "/tmp/x.sock";
+process.env.CLAUDE_PLUGIN_ROOT = "/some/cache/dir";
+process.env.CLAUDE_CONFIG_DIR = "/Users/x/.claude-work";
+process.env.CLAUDE_CODE_USE_BEDROCK = "1";
+process.env.ANTHROPIC_BASE_URL = "https://example.invalid";
+
+require("../index");
+const { db } = require("../db");
+
+after(() => {
+  db.close();
+  fs.rmSync(TMP, { recursive: true, force: true });
+});
+
+it("strips the parent session's variables and keeps user configuration", () => {
+  for (const k of [
+    "CLAUDECODE",
+    "CLAUDE_CODE_ENTRYPOINT",
+    "CLAUDE_CODE_SESSION_ID",
+    "CLAUDE_CODE_MESSAGING_SOCKET",
+    "CLAUDE_PLUGIN_ROOT",
+  ]) {
+    assert.equal(process.env[k], undefined, k);
+  }
+  assert.equal(process.env.CLAUDE_CONFIG_DIR, "/Users/x/.claude-work");
+  assert.equal(process.env.CLAUDE_CODE_USE_BEDROCK, "1");
+  assert.equal(process.env.ANTHROPIC_BASE_URL, "https://example.invalid");
+});
diff --git a/server/__tests__/lanes-lib.test.js b/server/__tests__/lanes-lib.test.js
index 75e14fd8..68de84c5 100644
--- a/server/__tests__/lanes-lib.test.js
+++ b/server/__tests__/lanes-lib.test.js
@@ -1269,3 +1269,21 @@ describe("the forward-only hold is short enough for one work session", () => {
     assert.equal(result, null);
   });
 });
+
+describe("createLane — canonical cwd (macOS /tmp -> /private/tmp class)", () => {
+  it("stores the realpath of a symlinked dir, and the given string when it does not exist yet", () => {
+    const fs = require("node:fs");
+    const base = fs.realpathSync(fs.mkdtempSync(pathMod.join(os.tmpdir(), "lane-realpath-")));
+    const target = pathMod.join(base, "real");
+    const link = pathMod.join(base, "link");
+    fs.mkdirSync(target);
+    fs.symlinkSync(target, link);
+    try {
+      assert.equal(lanes.createLane({ cwd: link + "/" }).cwd, target);
+      const missing = pathMod.join(base, "not-yet");
+      assert.equal(lanes.createLane({ cwd: missing }).cwd, missing);
+    } finally {
+      fs.rmSync(base, { recursive: true, force: true });
+    }
+  });
+});
diff --git a/server/__tests__/plugin-bootstrap.test.js b/server/__tests__/plugin-bootstrap.test.js
index d542a1c0..e4353baf 100644
--- a/server/__tests__/plugin-bootstrap.test.js
+++ b/server/__tests__/plugin-bootstrap.test.js
@@ -61,6 +61,16 @@ describe("serverIsLive", () => {
     assert.equal(boot.serverIsLive(), true);
     assert.deepEqual(boot.liveServers(), [{ port: 4820, pid: process.pid, startedAt: "x" }]);
   });
+
+  it("ignores an entry started before this boot, even when its pid is alive (pid reuse)", () => {
+    const beforeBoot = new Date(Date.now() - os.uptime() * 1000 - 3600_000).toISOString();
+    fs.writeFileSync(
+      infoPath,
+      JSON.stringify({ servers: [{ port: 4820, pid: process.pid, startedAt: beforeBoot }] })
+    );
+    assert.equal(boot.serverIsLive(), false);
+    assert.deepEqual(boot.liveServers(), []);
+  });
 });
 
 describe("runtime location", () => {
@@ -419,6 +429,26 @@ describe("agenthub CLI launcher", () => {
     assert.equal(boot.linkCli(bin), "foreign");
     assert.match(fs.readFileSync(target, "utf8"), /my\/checkout/);
   });
+
+  it(
+    "falls back to `node` on PATH when the pinned node binary is gone (brew upgrade)",
+    { skip: process.platform === "win32" },
+    () => {
+      const root = path.join(TMP_HOME, "fake-root");
+      fs.mkdirSync(path.join(root, "bin"), { recursive: true });
+      fs.writeFileSync(
+        path.join(root, "bin", "agenthub.js"),
+        "console.log('ran:' + process.argv.slice(2).join(','));\n"
+      );
+      assert.equal(boot.linkCli(bin, root, "/nonexistent/Cellar/node/0.0.0/bin/node"), "written");
+      assert.match(fs.readFileSync(target, "utf8"), /\/nonexistent\/Cellar/);
+      const out = require("child_process").execFileSync("sh", [target, "a", "b c"], {
+        encoding: "utf8",
+        env: { ...process.env, PATH: `${path.dirname(process.execPath)}:/usr/bin:/bin` },
+      });
+      assert.equal(out.trim(), "ran:a,b c");
+    }
+  );
 });
 
 describe("plugin-open / plugin-bootstrap require cycle", () => {
diff --git a/server/__tests__/session-liveness.test.js b/server/__tests__/session-liveness.test.js
index 97f85eeb..d077cbae 100644
--- a/server/__tests__/session-liveness.test.js
+++ b/server/__tests__/session-liveness.test.js
@@ -393,3 +393,55 @@ describe("watchdog liveness reap", () => {
     assert.equal(stmts.getSession.get(sid).status, "completed");
   });
 });
+
+describe("probeLiveCwds — darwin branch (ps + lsof, stubbed)", () => {
+  const realPlatform = process.platform;
+  const PS =
+    "  101 /opt/homebrew/bin/claude --resume x\n  102 node /Users/x/claude-dashboard/index.js\n  103 claude\n";
+  const LSOF = "p101\nfcwd\nn/Users/x/proj\np103\nfcwd\nn/private/tmp/other\n";
+  let calls;
+
+  beforeEach(() => {
+    delete process.env.DASHBOARD_LIVENESS_PROBE;
+    process.env.AGENTHUB_FORCE_HOST = "1";
+    Object.defineProperty(process, "platform", { value: "darwin", configurable: true });
+    calls = [];
+  });
+  after(() => {
+    Object.defineProperty(process, "platform", { value: realPlatform, configurable: true });
+    liveness.__setExecImpl(null);
+    delete process.env.AGENTHUB_FORCE_HOST;
+    process.env.DASHBOARD_LIVENESS_PROBE = "0";
+  });
+
+  it("reads each claude pid's cwd from lsof -Fn records", () => {
+    liveness.__setExecImpl((bin, args) => {
+      calls.push([bin, args]);
+      return bin === "ps" ? PS : LSOF;
+    });
+    const r = realProbe();
+    assert.equal(r.available, true);
+    assert.deepEqual([...r.cwds].sort(), ["/Users/x/proj", "/private/tmp/other"]);
+    assert.deepEqual(calls[1], ["lsof", ["-a", "-p", "101,103", "-d", "cwd", "-Fn"]]);
+  });
+
+  it("keeps lsof's partial output when it exits 1 because a pid vanished", () => {
+    liveness.__setExecImpl((bin) => {
+      if (bin === "ps") return PS;
+      const err = new Error("exit 1");
+      err.stdout = "p101\nfcwd\nn/Users/x/proj\n";
+      throw err;
+    });
+    const r = realProbe();
+    assert.equal(r.available, true);
+    assert.deepEqual([...r.cwds], ["/Users/x/proj"]);
+  });
+
+  it("reports unavailable when lsof fails with no output", () => {
+    liveness.__setExecImpl((bin) => {
+      if (bin === "ps") return PS;
+      throw Object.assign(new Error("ENOENT"), { stdout: "" });
+    });
+    assert.equal(realProbe().available, false);
+  });
+});
diff --git a/server/index.js b/server/index.js
index 42cdf0f0..cf15f57c 100644
--- a/server/index.js
+++ b/server/index.js
@@ -5,6 +5,18 @@
 
 if (!process.env.NODE_ENV) process.env.NODE_ENV = "production";
 
+// A server started from inside a Claude Code session (the bootstrap fallback,
+// always the case on macOS) inherits that session's own variables, and tmux
+// hands them to every lane pane — whose `claude` then believes it is nested.
+// ponytail: a DENYLIST of parent-session variables only, so user config
+// (CLAUDE_CONFIG_DIR, CLAUDE_CODE_USE_BEDROCK, ANTHROPIC_*) passes through;
+// it must grow when Claude Code adds a new per-session variable.
+const PARENT_SESSION_VARS =
+  /^(CLAUDECODE|CLAUDE_PID|CLAUDE_PROJECT_DIR|CLAUDE_ENV_FILE|CLAUDE_PLUGIN_(ROOT|DATA)|CLAUDE_CODE_(ENTRYPOINT|SESSION_ID|CHILD_SESSION|SESSION_ATTENDED|EXECPATH|MESSAGING_.*))$/;
+for (const k of Object.keys(process.env)) {
+  if (PARENT_SESSION_VARS.test(k)) delete process.env[k];
+}
+
 // Load .env file (simple key=value, no external dependency needed)
 (function loadDotEnv() {
   const fs = require("fs");
diff --git a/server/lib/lanes.js b/server/lib/lanes.js
index 9faa67c0..c752be76 100644
--- a/server/lib/lanes.js
+++ b/server/lib/lanes.js
@@ -160,6 +160,24 @@ function normalizeTitle(value) {
   return String(value).trim().slice(0, TITLE_MAX);
 }
 
+/**
+ * The path the OS calls this directory: macOS hands a session `/private/tmp/x`
+ * for a typed `/tmp/x`, and a case-insensitive volume accepts `~/Code` for
+ * `~/code`, so a lane stored under the typed string would never bind a
+ * session. A path that does not exist yet (a worktree lane is created before
+ * its directory) keeps the string it was given.
+ */
+function canonicalCwd(cwd) {
+  // A relative path must stay relative, so createLane still refuses it.
+  if (!cwd.startsWith("/")) return cwd;
+  const trimmed = cwd.replace(/\/+$/, "");
+  try {
+    return require("node:fs").realpathSync.native(trimmed);
+  } catch {
+    return trimmed;
+  }
+}
+
 function createLane({
   title = "",
   cwd,
@@ -184,7 +202,7 @@ function createLane({
     )
     .run(
       normalizeTitle(title),
-      cwd.replace(/\/+$/, ""),
+      canonicalCwd(cwd),
       branch,
       pipeline,
       kind,
@@ -842,6 +860,7 @@ module.exports = {
   DEAD_SEC,
   VALID_TOOLS,
   detectionIsStale,
+  canonicalCwd,
   createLane,
   listLanes,
   getLane,
diff --git a/server/lib/session-liveness.js b/server/lib/session-liveness.js
index e350839a..b6d12aef 100644
--- a/server/lib/session-liveness.js
+++ b/server/lib/session-liveness.js
@@ -21,6 +21,13 @@ const fs = require("node:fs");
 const path = require("node:path");
 const { isInsideContainer } = require("../../scripts/install-hooks");
 
+let execImpl = execFileSync;
+
+/** Test seam — same pattern as tmux.js / desktop-env.js. */
+function __setExecImpl(fn) {
+  execImpl = fn || execFileSync;
+}
+
 const UNAVAILABLE = () => ({ available: false, cwds: new Set() });
 
 /**
@@ -62,7 +69,7 @@ function probeLiveCwds() {
 
   let psOut;
   try {
-    psOut = execFileSync("ps", ["-Ao", "pid=,args="], {
+    psOut = execImpl("ps", ["-Ao", "pid=,args="], {
       encoding: "utf8",
       timeout: 5_000,
       maxBuffer: 16 * 1024 * 1024,
@@ -95,7 +102,7 @@ function probeLiveCwds() {
   // machine format emits `p<pid>` / `f cwd` / `n<path>` records.
   let lsofOut;
   try {
-    lsofOut = execFileSync("lsof", ["-a", "-p", pids.join(","), "-d", "cwd", "-Fn"], {
+    lsofOut = execImpl("lsof", ["-a", "-p", pids.join(","), "-d", "cwd", "-Fn"], {
       encoding: "utf8",
       timeout: 10_000,
       maxBuffer: 16 * 1024 * 1024,
@@ -113,4 +120,4 @@ function probeLiveCwds() {
   return { available: true, cwds };
 }
 
-module.exports = { probeLiveCwds, isClaudeCommand };
+module.exports = { probeLiveCwds, isClaudeCommand, __setExecImpl };
diff --git a/server/openapi-extra/lanes.js b/server/openapi-extra/lanes.js
index ae7cd2d8..bbb4904b 100644
--- a/server/openapi-extra/lanes.js
+++ b/server/openapi-extra/lanes.js
@@ -116,7 +116,7 @@ const paths = {
       tags: ["Lanes"],
       summary: "Find or adopt the lane owning a working directory",
       description:
-        "Idempotent: returns the lane whose cwd is an exact match or the longest path-boundary parent of `cwd` with `created: false` (200) — with `exact: true` only an exact match counts, so a directory nested inside another lane gets a lane of its own (the Add-lane modal sends it) — otherwise creates an `adopted` lane and returns it with `created: true` (201). The Workspace page opens on a directory rather than a lane id, so this is how it gets exactly one lane for that directory. Concurrent calls for the same path resolve to ONE lane: the `lanes.cwd` UNIQUE constraint decides, and the loser re-reads and returns the winner's lane.",
+        "Idempotent: canonicalizes `cwd` to its real path when it exists (the same path `createLane` stores), then returns the lane whose cwd is an exact match or the longest path-boundary parent of `cwd` with `created: false` (200) — with `exact: true` only an exact match counts, so a directory nested inside another lane gets a lane of its own (the Add-lane modal sends it) — otherwise creates an `adopted` lane and returns it with `created: true` (201). The Workspace page opens on a directory rather than a lane id, so this is how it gets exactly one lane for that directory. Concurrent calls for the same path resolve to ONE lane: the `lanes.cwd` UNIQUE constraint decides, and the loser re-reads and returns the winner's lane.",
       operationId: "ensureLane",
       requestBody: {
         required: true,
diff --git a/server/routes/hooks.js b/server/routes/hooks.js
index 7817ecd1..f056d1cc 100644
--- a/server/routes/hooks.js
+++ b/server/routes/hooks.js
@@ -1592,6 +1592,13 @@ function livenessReap({ ignoreIdleGate = false } = {}) {
       continue;
     }
     if (probe.cwds.has(resolvedCwd)) continue;
+    // lsof reports the OS's own path (/private/tmp on macOS); a session row may
+    // hold the symlinked or differently-cased spelling of the same directory.
+    try {
+      if (probe.cwds.has(require("fs").realpathSync.native(resolvedCwd))) continue;
+    } catch {
+      /* directory gone — the process cannot be sitting in it either */
+    }
 
     // Idle gate (watchdog ticks only — boot passes skip it, see above): the
     // transcript mtime is the ground truth for "when did this session last
diff --git a/server/routes/lanes.js b/server/routes/lanes.js
index 97f4c495..ae2bbf0b 100644
--- a/server/routes/lanes.js
+++ b/server/routes/lanes.js
@@ -319,7 +319,10 @@ router.post("/ensure", sameOriginGuard, (req, res) => {
   // specific directory (e.g. Sagi's mascot companion) get a real, existing
   // path and lane uniqueness stays meaningful. Callers that do care pass one
   // through unchanged.
-  const cwd = typeof body.cwd === "string" && body.cwd.trim() ? body.cwd.trim() : os.homedir();
+  // Canonical before the lookup, so the lookup and createLane's insert agree.
+  const cwd = lanesLib.canonicalCwd(
+    typeof body.cwd === "string" && body.cwd.trim() ? body.cwd.trim() : os.homedir()
+  );
 
   if (body.tool !== undefined && !lanesLib.VALID_TOOLS.has(body.tool)) {
     return res.status(400).json({ error: { code: "EBADTOOL", message: "unknown tool" } });