diff --git a/.github/workflows/install-smoke.yml b/.github/workflows/install-smoke.yml
new file mode 100644
index 000000000..49c215bf1
--- /dev/null
+++ b/.github/workflows/install-smoke.yml
@@ -0,0 +1,34 @@
+name: Install Smoke
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  install-smoke:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout CLI
+        uses: actions/checkout@v4
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v3
+        with:
+          version: 10
+      - name: Enable Corepack
+        run: corepack enable
+
+      - name: Clone installer site
+        run: git clone --depth=1 https://github.com/clawdbot/clawd.bot ../clawd.bot
+
+      - name: Install pnpm deps (minimal)
+        run: pnpm install --ignore-scripts --frozen-lockfile
+
+      - name: Run installer docker tests
+        env:
+          CLAWDBOT_INSTALL_URL: file://$GITHUB_WORKSPACE/../clawd.bot/public/install.sh
+          CLAWDBOT_INSTALL_CLI_URL: file://$GITHUB_WORKSPACE/../clawd.bot/public/install-cli.sh
+          CLAWDBOT_NO_ONBOARD: "1"
+        run: pnpm test:install:e2e
diff --git a/CHANGELOG.md b/CHANGELOG.md
index bbf9bde26..360e19f65 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,11 @@
 - Discord: expose channel/category management actions in the message tool. (#730) — thanks @NicholasSpisak
 - Docs: rename README “macOS app” section to “Apps”. (#733) — thanks @AbhisekBasu1.
 
+### Installer
+- Postinstall: replace `git apply` with builtin JS patcher (works npm/pnpm/bun; no git dependency) plus regression tests.
+- Installer tests: add root+non-root docker smokes, CI workflow to fetch clawd.bot scripts and run install sh/cli with onboarding skipped.
+- Installer UX: support `CLAWDBOT_NO_ONBOARD=1` for non-interactive installs; fix npm prefix on Linux and auto-install git.
+
 ### Fixes
 - Gateway/WebChat: include handshake validation details in the WebSocket close reason for easier debugging.
 - Doctor: surface plugin diagnostics in the report.
diff --git a/scripts/docker/install-sh-nonroot/Dockerfile b/scripts/docker/install-sh-nonroot/Dockerfile
new file mode 100644
index 000000000..18a3c82b5
--- /dev/null
+++ b/scripts/docker/install-sh-nonroot/Dockerfile
@@ -0,0 +1,23 @@
+FROM ubuntu:24.04
+
+RUN apt-get update \
+  && apt-get install -y --no-install-recommends \
+    bash \
+    ca-certificates \
+    curl \
+    sudo \
+  && rm -rf /var/lib/apt/lists/*
+
+RUN useradd -m -s /bin/bash app \
+  && echo "app ALL=(ALL) NOPASSWD:ALL" > /etc/sudoers.d/app
+
+USER app
+WORKDIR /home/app
+
+ENV NPM_CONFIG_FUND=false
+ENV NPM_CONFIG_AUDIT=false
+
+COPY run.sh /usr/local/bin/clawdbot-install-nonroot
+RUN sudo chmod +x /usr/local/bin/clawdbot-install-nonroot
+
+ENTRYPOINT ["/usr/local/bin/clawdbot-install-nonroot"]
diff --git a/scripts/docker/install-sh-nonroot/run.sh b/scripts/docker/install-sh-nonroot/run.sh
new file mode 100644
index 000000000..a04b89c15
--- /dev/null
+++ b/scripts/docker/install-sh-nonroot/run.sh
@@ -0,0 +1,42 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+INSTALL_URL="${CLAWDBOT_INSTALL_URL:-https://clawd.bot/install.sh}"
+
+echo "==> Pre-flight: ensure git absent"
+if command -v git >/dev/null; then
+  echo "git is present unexpectedly" >&2
+  exit 1
+fi
+
+echo "==> Run installer (non-root user)"
+curl -fsSL "$INSTALL_URL" | bash
+
+# Ensure PATH picks up user npm prefix
+export PATH="$HOME/.npm-global/bin:$PATH"
+
+echo "==> Verify git installed"
+command -v git >/dev/null
+
+echo "==> Verify clawdbot installed"
+LATEST_VERSION="$(npm view clawdbot version)"
+CMD_PATH="$(command -v clawdbot || true)"
+if [[ -z "$CMD_PATH" && -x "$HOME/.npm-global/bin/clawdbot" ]]; then
+  CMD_PATH="$HOME/.npm-global/bin/clawdbot"
+fi
+if [[ -z "$CMD_PATH" ]]; then
+  echo "clawdbot not on PATH" >&2
+  exit 1
+fi
+INSTALLED_VERSION="$("$CMD_PATH" --version 2>/dev/null | head -n 1 | tr -d '\r')"
+
+echo "installed=$INSTALLED_VERSION expected=$LATEST_VERSION"
+if [[ "$INSTALLED_VERSION" != "$LATEST_VERSION" ]]; then
+  echo "ERROR: expected clawdbot@$LATEST_VERSION, got @$INSTALLED_VERSION" >&2
+  exit 1
+fi
+
+echo "==> Sanity: CLI runs"
+"$CMD_PATH" --help >/dev/null
+
+echo "OK"
diff --git a/scripts/docker/install-sh-smoke/Dockerfile b/scripts/docker/install-sh-smoke/Dockerfile
index 638c77c67..4888e3cd7 100644
--- a/scripts/docker/install-sh-smoke/Dockerfile
+++ b/scripts/docker/install-sh-smoke/Dockerfile
@@ -5,7 +5,7 @@ RUN apt-get update \
     bash \
     ca-certificates \
     curl \
-    git \
+    sudo \
   && rm -rf /var/lib/apt/lists/*
 
 COPY run.sh /usr/local/bin/clawdbot-install-smoke
diff --git a/scripts/postinstall.js b/scripts/postinstall.js
index f849c02fd..cc504933f 100644
--- a/scripts/postinstall.js
+++ b/scripts/postinstall.js
@@ -1,73 +1,12 @@
-import { spawnSync } from "node:child_process";
 import fs from "node:fs";
 import path from "node:path";
 import { fileURLToPath } from "node:url";
 
-function isBunInstall() {
-  const ua = process.env.npm_config_user_agent ?? "";
-  return ua.includes("bun/");
-}
-
 function getRepoRoot() {
   const here = path.dirname(fileURLToPath(import.meta.url));
   return path.resolve(here, "..");
 }
 
-function run(cmd, args, opts = {}) {
-  const res = spawnSync(cmd, args, { stdio: "inherit", ...opts });
-  if (typeof res.status === "number") return res.status;
-  return 1;
-}
-
-function applyPatchIfNeeded(opts) {
-  const patchPath = path.resolve(opts.patchPath);
-  if (!fs.existsSync(patchPath)) {
-    throw new Error(`missing patch: ${patchPath}`);
-  }
-
-  let targetDir = path.resolve(opts.targetDir);
-  if (!fs.existsSync(targetDir) || !fs.statSync(targetDir).isDirectory()) {
-    console.warn(`[postinstall] skip missing target: ${targetDir}`);
-    return;
-  }
-
-  // Resolve symlinks to avoid "beyond a symbolic link" errors from git apply
-  // (bun/pnpm use symlinks in node_modules)
-  targetDir = fs.realpathSync(targetDir);
-
-  const gitArgsBase = ["apply", "--unsafe-paths", "--whitespace=nowarn"];
-  const reverseCheck = [
-    ...gitArgsBase,
-    "--reverse",
-    "--check",
-    "--directory",
-    targetDir,
-    patchPath,
-  ];
-  const forwardCheck = [
-    ...gitArgsBase,
-    "--check",
-    "--directory",
-    targetDir,
-    patchPath,
-  ];
-  const apply = [...gitArgsBase, "--directory", targetDir, patchPath];
-
-  // Already applied?
-  if (run("git", reverseCheck, { stdio: "ignore" }) === 0) {
-    return;
-  }
-
-  if (run("git", forwardCheck, { stdio: "ignore" }) !== 0) {
-    throw new Error(`patch does not apply cleanly: ${path.basename(patchPath)}`);
-  }
-
-  const status = run("git", apply);
-  if (status !== 0) {
-    throw new Error(`failed applying patch: ${path.basename(patchPath)}`);
-  }
-}
-
 function extractPackageName(key) {
   if (key.startsWith("@")) {
     const idx = key.indexOf("@", 1);
@@ -79,9 +18,180 @@ function extractPackageName(key) {
   return key.slice(0, idx);
 }
 
-function main() {
-  if (!isBunInstall()) return;
+function stripPrefix(p) {
+  if (p.startsWith("a/") || p.startsWith("b/")) return p.slice(2);
+  return p;
+}
 
+function parseRange(segment) {
+  // segment: "-12,5" or "+7"
+  const [startRaw, countRaw] = segment.slice(1).split(",");
+  const start = Number.parseInt(startRaw, 10);
+  const count = countRaw ? Number.parseInt(countRaw, 10) : 1;
+  if (Number.isNaN(start) || Number.isNaN(count)) {
+    throw new Error(`invalid hunk range: ${segment}`);
+  }
+  return { start, count };
+}
+
+function parsePatch(patchText) {
+  const lines = patchText.split("\n");
+  const files = [];
+  let i = 0;
+
+  while (i < lines.length) {
+    if (!lines[i].startsWith("diff --git ")) {
+      i += 1;
+      continue;
+    }
+
+    const file = { oldPath: null, newPath: null, hunks: [] };
+    i += 1;
+
+    // Skip index line(s)
+    while (i < lines.length && lines[i].startsWith("index ")) i += 1;
+
+    if (i < lines.length && lines[i].startsWith("--- ")) {
+      file.oldPath = stripPrefix(lines[i].slice(4).trim());
+      i += 1;
+    }
+    if (i < lines.length && lines[i].startsWith("+++ ")) {
+      file.newPath = stripPrefix(lines[i].slice(4).trim());
+      i += 1;
+    }
+
+    while (i < lines.length && lines[i].startsWith("@@")) {
+      const header = lines[i];
+      const match = /^@@\s+(-\d+(?:,\d+)?)\s+(\+\d+(?:,\d+)?)\s+@@/.exec(header);
+      if (!match) throw new Error(`invalid hunk header: ${header}`);
+      const oldRange = parseRange(match[1]);
+      const newRange = parseRange(match[2]);
+      i += 1;
+
+      const hunkLines = [];
+      while (i < lines.length) {
+        const line = lines[i];
+        if (line.startsWith("@@") || line.startsWith("diff --git ")) break;
+        if (line === "") {
+          i += 1;
+          continue;
+        }
+        if (line.startsWith("\\ No newline at end of file")) {
+          i += 1;
+          continue;
+        }
+        hunkLines.push(line);
+        i += 1;
+      }
+
+      file.hunks.push({
+        oldStart: oldRange.start,
+        oldLines: oldRange.count,
+        newStart: newRange.start,
+        newLines: newRange.count,
+        lines: hunkLines,
+      });
+    }
+
+    if (file.newPath && file.hunks.length > 0) {
+      files.push(file);
+    }
+  }
+
+  return files;
+}
+
+function readFileLines(targetPath) {
+  if (!fs.existsSync(targetPath)) {
+    throw new Error(`target file missing: ${targetPath}`);
+  }
+  const raw = fs.readFileSync(targetPath, "utf-8");
+  const hasTrailingNewline = raw.endsWith("\n");
+  const parts = raw.split("\n");
+  if (hasTrailingNewline) parts.pop();
+  return { lines: parts, hasTrailingNewline };
+}
+
+function writeFileLines(targetPath, lines, hadTrailingNewline) {
+  const content = lines.join("\n") + (hadTrailingNewline ? "\n" : "");
+  fs.writeFileSync(targetPath, content, "utf-8");
+}
+
+function applyHunk(lines, hunk, offset) {
+  let cursor = hunk.oldStart - 1 + offset;
+
+  for (const raw of hunk.lines) {
+    const marker = raw[0];
+    const text = raw.slice(1);
+    if (marker === " ") {
+      if (lines[cursor] !== text) {
+        throw new Error(
+          `context mismatch at line ${cursor + 1}: expected "${text}", found "${lines[cursor] ?? "<eof>"}"`,
+        );
+      }
+      cursor += 1;
+    } else if (marker === "-") {
+      if (lines[cursor] !== text) {
+        throw new Error(
+          `delete mismatch at line ${cursor + 1}: expected "${text}", found "${lines[cursor] ?? "<eof>"}"`,
+        );
+      }
+      lines.splice(cursor, 1);
+    } else if (marker === "+") {
+      lines.splice(cursor, 0, text);
+      cursor += 1;
+    } else {
+      throw new Error(`unexpected hunk marker: ${marker}`);
+    }
+  }
+
+  const delta = hunk.newLines - hunk.oldLines;
+  return offset + delta;
+}
+
+function applyPatchToFile(targetDir, filePatch) {
+  if (filePatch.newPath === "/dev/null") {
+    // deletion not needed for our patches
+    return;
+  }
+  const relPath = stripPrefix(filePatch.newPath ?? filePatch.oldPath ?? "");
+  const targetPath = path.join(targetDir, relPath);
+  const { lines, hasTrailingNewline } = readFileLines(targetPath);
+
+  let offset = 0;
+  for (const hunk of filePatch.hunks) {
+    offset = applyHunk(lines, hunk, offset);
+  }
+
+  writeFileLines(targetPath, lines, hasTrailingNewline);
+}
+
+function applyPatchSet({ patchText, targetDir }) {
+  let resolvedTarget = path.resolve(targetDir);
+  if (!fs.existsSync(resolvedTarget) || !fs.statSync(resolvedTarget).isDirectory()) {
+    console.warn(`[postinstall] skip missing target: ${resolvedTarget}`);
+    return;
+  }
+  resolvedTarget = fs.realpathSync(resolvedTarget);
+
+  const files = parsePatch(patchText);
+  if (files.length === 0) return;
+
+  for (const filePatch of files) {
+    applyPatchToFile(resolvedTarget, filePatch);
+  }
+}
+
+function applyPatchFile({ patchPath, targetDir }) {
+  const absPatchPath = path.resolve(patchPath);
+  if (!fs.existsSync(absPatchPath)) {
+    throw new Error(`missing patch: ${absPatchPath}`);
+  }
+  const patchText = fs.readFileSync(absPatchPath, "utf-8");
+  applyPatchSet({ patchText, targetDir });
+}
+
+function main() {
   const repoRoot = getRepoRoot();
   process.chdir(repoRoot);
 
@@ -95,7 +205,7 @@ function main() {
     if (typeof relPatchPath !== "string" || !relPatchPath.trim()) continue;
     const pkgName = extractPackageName(String(key));
     if (!pkgName) continue;
-    applyPatchIfNeeded({
+    applyPatchFile({
       targetDir: path.join("node_modules", ...pkgName.split("/")),
       patchPath: relPatchPath,
     });
@@ -103,8 +213,22 @@ function main() {
 }
 
 try {
-  main();
+  const skip =
+    process.env.CLAWDBOT_SKIP_POSTINSTALL === "1" ||
+    process.env.VITEST === "true" ||
+    process.env.NODE_ENV === "test";
+
+  if (!skip) {
+    main();
+  }
 } catch (err) {
   console.error(String(err));
   process.exit(1);
 }
+
+export {
+  applyPatchFile,
+  applyPatchSet,
+  applyPatchToFile,
+  parsePatch,
+};
diff --git a/scripts/test-install-sh-docker.sh b/scripts/test-install-sh-docker.sh
index 440fa7015..00bc744de 100755
--- a/scripts/test-install-sh-docker.sh
+++ b/scripts/test-install-sh-docker.sh
@@ -2,16 +2,38 @@
 set -euo pipefail
 
 ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
-IMAGE_NAME="${CLAWDBOT_INSTALL_SMOKE_IMAGE:-clawdbot-install-smoke:local}"
+SMOKE_IMAGE="${CLAWDBOT_INSTALL_SMOKE_IMAGE:-clawdbot-install-smoke:local}"
+NONROOT_IMAGE="${CLAWDBOT_INSTALL_NONROOT_IMAGE:-clawdbot-install-nonroot:local}"
 INSTALL_URL="${CLAWDBOT_INSTALL_URL:-https://clawd.bot/install.sh}"
+CLI_INSTALL_URL="${CLAWDBOT_INSTALL_CLI_URL:-https://clawd.bot/install-cli.sh}"
 
-echo "==> Build image: $IMAGE_NAME"
+echo "==> Build smoke image (upgrade, root): $SMOKE_IMAGE"
 docker build \
-  -t "$IMAGE_NAME" \
+  -t "$SMOKE_IMAGE" \
   -f "$ROOT_DIR/scripts/docker/install-sh-smoke/Dockerfile" \
   "$ROOT_DIR/scripts/docker/install-sh-smoke"
 
-echo "==> Run installer smoke test: $INSTALL_URL"
+echo "==> Run installer smoke test (root): $INSTALL_URL"
 docker run --rm -t \
   -e CLAWDBOT_INSTALL_URL="$INSTALL_URL" \
-  "$IMAGE_NAME"
+  -e CLAWDBOT_NO_ONBOARD=1 \
+  "$SMOKE_IMAGE"
+
+echo "==> Build non-root image: $NONROOT_IMAGE"
+docker build \
+  -t "$NONROOT_IMAGE" \
+  -f "$ROOT_DIR/scripts/docker/install-sh-nonroot/Dockerfile" \
+  "$ROOT_DIR/scripts/docker/install-sh-nonroot"
+
+echo "==> Run installer non-root test: $INSTALL_URL"
+docker run --rm -t \
+  -e CLAWDBOT_INSTALL_URL="$INSTALL_URL" \
+  -e CLAWDBOT_NO_ONBOARD=1 \
+  "$NONROOT_IMAGE"
+
+echo "==> Run CLI installer non-root test (same image)"
+docker run --rm -t \
+  -e CLAWDBOT_INSTALL_URL="$INSTALL_URL" \
+  -e CLAWDBOT_INSTALL_CLI_URL="$CLI_INSTALL_URL" \
+  -e CLAWDBOT_NO_ONBOARD=1 \
+  "$NONROOT_IMAGE" bash -lc "curl -fsSL \"$CLI_INSTALL_URL\" | bash -s -- --set-npm-prefix --no-onboard"
diff --git a/src/postinstall-patcher.test.ts b/src/postinstall-patcher.test.ts
new file mode 100644
index 000000000..44dfe2e01
--- /dev/null
+++ b/src/postinstall-patcher.test.ts
@@ -0,0 +1,117 @@
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import { describe, expect, it } from "vitest";
+
+import { applyPatchSet } from "../scripts/postinstall.js";
+
+function makeTempDir() {
+  return fs.mkdtempSync(path.join(os.tmpdir(), "clawdbot-patch-"));
+}
+
+describe("postinstall patcher", () => {
+  it("applies a simple patch", () => {
+    const dir = makeTempDir();
+    const target = path.join(dir, "lib");
+    fs.mkdirSync(target);
+
+    const filePath = path.join(target, "main.js");
+    const original = [
+      "var QRCode = require('./../vendor/QRCode'),",
+      "    QRErrorCorrectLevel = require('./../vendor/QRCode/QRErrorCorrectLevel'),",
+      '    black = "\\033[40m  \\033[0m",',
+      '    white = "\\033[47m  \\033[0m",',
+      "    toCell = function (isBlack) {",
+    ].join("\n") + "\n";
+    fs.writeFileSync(filePath, original, "utf-8");
+
+    const patchText = `diff --git a/lib/main.js b/lib/main.js
+index 0000000..1111111 100644
+--- a/lib/main.js
++++ b/lib/main.js
+@@ -1,5 +1,5 @@
+-var QRCode = require('./../vendor/QRCode'),
+-    QRErrorCorrectLevel = require('./../vendor/QRCode/QRErrorCorrectLevel'),
++var QRCode = require('./../vendor/QRCode/index.js'),
++    QRErrorCorrectLevel = require('./../vendor/QRCode/QRErrorCorrectLevel.js'),
+     black = "\\033[40m  \\033[0m",
+     white = "\\033[47m  \\033[0m",
+     toCell = function (isBlack) {
+`;
+
+    applyPatchSet({ patchText, targetDir: dir });
+
+    const updated = fs.readFileSync(filePath, "utf-8");
+    expect(updated).toBe(
+      [
+        "var QRCode = require('./../vendor/QRCode/index.js'),",
+        "    QRErrorCorrectLevel = require('./../vendor/QRCode/QRErrorCorrectLevel.js'),",
+        '    black = "\\033[40m  \\033[0m",',
+        '    white = "\\033[47m  \\033[0m",',
+        "    toCell = function (isBlack) {",
+      ].join("\n") + "\n",
+    );
+
+    fs.rmSync(dir, { recursive: true, force: true });
+  });
+
+  it("handles multiple hunks with offsets", () => {
+    const dir = makeTempDir();
+    const filePath = path.join(dir, "file.txt");
+    fs.writeFileSync(
+      filePath,
+      ["alpha", "beta", "gamma", "delta", "epsilon"].join("\n") + "\n",
+      "utf-8",
+    );
+
+    const patchText = `diff --git a/file.txt b/file.txt
+--- a/file.txt
++++ b/file.txt
+@@ -1,3 +1,4 @@
+ alpha
+ beta
++beta2
+ gamma
+@@ -3,3 +4,4 @@
+ gamma
+-delta
++DELTA
+ epsilon
++zeta
+`;
+
+    applyPatchSet({ patchText, targetDir: dir });
+
+    const updated = fs.readFileSync(filePath, "utf-8").trim().split("\n");
+    expect(updated).toEqual([
+      "alpha",
+      "beta",
+      "beta2",
+      "gamma",
+      "DELTA",
+      "epsilon",
+      "zeta",
+    ]);
+
+    fs.rmSync(dir, { recursive: true, force: true });
+  });
+
+  it("throws on context mismatch", () => {
+    const dir = makeTempDir();
+    const filePath = path.join(dir, "file.txt");
+    fs.writeFileSync(filePath, "hello\nworld\n", "utf-8");
+
+    const patchText = `diff --git a/file.txt b/file.txt
+--- a/file.txt
++++ b/file.txt
+@@ -1,2 +1,2 @@
+-hola
++hi
+ world
+`;
+
+    expect(() => applyPatchSet({ patchText, targetDir: dir })).toThrow();
+
+    fs.rmSync(dir, { recursive: true, force: true });
+  });
+});