diff --git a/.github/workflows/rust-release.yml b/.github/workflows/rust-release.yml
index 4ed08b077e3d..2d137de6ff72 100644
--- a/.github/workflows/rust-release.yml
+++ b/.github/workflows/rust-release.yml
@@ -494,6 +494,10 @@ jobs:
             --package codex-responses-api-proxy \
             --package codex-sdk
 
+      - name: Stage macOS and Linux installer script
+        run: |
+          cp scripts/install/install.sh dist/install.sh
+
       - name: Create GitHub Release
         uses: softprops/action-gh-release@v2
         with:
diff --git a/scripts/install/install.sh b/scripts/install/install.sh
new file mode 100755
index 000000000000..86e2940d5530
--- /dev/null
+++ b/scripts/install/install.sh
@@ -0,0 +1,244 @@
+#!/bin/sh
+
+set -eu
+
+VERSION="${1:-latest}"
+INSTALL_DIR="${CODEX_INSTALL_DIR:-$HOME/.local/bin}"
+path_action="already"
+path_profile=""
+
+step() {
+  printf '==> %s\n' "$1"
+}
+
+normalize_version() {
+  case "$1" in
+    "" | latest)
+      printf 'latest\n'
+      ;;
+    rust-v*)
+      printf '%s\n' "${1#rust-v}"
+      ;;
+    v*)
+      printf '%s\n' "${1#v}"
+      ;;
+    *)
+      printf '%s\n' "$1"
+      ;;
+  esac
+}
+
+download_file() {
+  url="$1"
+  output="$2"
+
+  if command -v curl >/dev/null 2>&1; then
+    curl -fsSL "$url" -o "$output"
+    return
+  fi
+
+  if command -v wget >/dev/null 2>&1; then
+    wget -q -O "$output" "$url"
+    return
+  fi
+
+  echo "curl or wget is required to install Codex." >&2
+  exit 1
+}
+
+download_text() {
+  url="$1"
+
+  if command -v curl >/dev/null 2>&1; then
+    curl -fsSL "$url"
+    return
+  fi
+
+  if command -v wget >/dev/null 2>&1; then
+    wget -q -O - "$url"
+    return
+  fi
+
+  echo "curl or wget is required to install Codex." >&2
+  exit 1
+}
+
+add_to_path() {
+  path_action="already"
+  path_profile=""
+
+  case ":$PATH:" in
+    *":$INSTALL_DIR:"*)
+      return
+      ;;
+  esac
+
+  profile="$HOME/.profile"
+  case "${SHELL:-}" in
+    */zsh)
+      profile="$HOME/.zshrc"
+      ;;
+    */bash)
+      profile="$HOME/.bashrc"
+      ;;
+  esac
+
+  path_profile="$profile"
+  path_line="export PATH=\"$INSTALL_DIR:\$PATH\""
+  if [ -f "$profile" ] && grep -F "$path_line" "$profile" >/dev/null 2>&1; then
+    path_action="configured"
+    return
+  fi
+
+  {
+    printf '\n# Added by Codex installer\n'
+    printf '%s\n' "$path_line"
+  } >>"$profile"
+  path_action="added"
+}
+
+release_url_for_asset() {
+  asset="$1"
+  resolved_version="$2"
+
+  printf 'https://github.com/openai/codex/releases/download/rust-v%s/%s\n' "$resolved_version" "$asset"
+}
+
+require_command() {
+  if ! command -v "$1" >/dev/null 2>&1; then
+    echo "$1 is required to install Codex." >&2
+    exit 1
+  fi
+}
+
+require_command mktemp
+require_command tar
+
+resolve_version() {
+  normalized_version="$(normalize_version "$VERSION")"
+
+  if [ "$normalized_version" != "latest" ]; then
+    printf '%s\n' "$normalized_version"
+    return
+  fi
+
+  release_json="$(download_text "https://api.github.com/repos/openai/codex/releases/latest")"
+  resolved="$(printf '%s\n' "$release_json" | sed -n 's/.*"tag_name":[[:space:]]*"rust-v\([^"]*\)".*/\1/p' | head -n 1)"
+
+  if [ -z "$resolved" ]; then
+    echo "Failed to resolve the latest Codex release version." >&2
+    exit 1
+  fi
+
+  printf '%s\n' "$resolved"
+}
+
+case "$(uname -s)" in
+  Darwin)
+    os="darwin"
+    ;;
+  Linux)
+    os="linux"
+    ;;
+  *)
+    echo "install.sh supports macOS and Linux. Use install.ps1 on Windows." >&2
+    exit 1
+    ;;
+esac
+
+case "$(uname -m)" in
+  x86_64 | amd64)
+    arch="x86_64"
+    ;;
+  arm64 | aarch64)
+    arch="aarch64"
+    ;;
+  *)
+    echo "Unsupported architecture: $(uname -m)" >&2
+    exit 1
+    ;;
+esac
+
+if [ "$os" = "darwin" ] && [ "$arch" = "x86_64" ]; then
+  if [ "$(sysctl -n sysctl.proc_translated 2>/dev/null || true)" = "1" ]; then
+    arch="aarch64"
+  fi
+fi
+
+if [ "$os" = "darwin" ]; then
+  if [ "$arch" = "aarch64" ]; then
+    npm_tag="darwin-arm64"
+    vendor_target="aarch64-apple-darwin"
+    platform_label="macOS (Apple Silicon)"
+  else
+    npm_tag="darwin-x64"
+    vendor_target="x86_64-apple-darwin"
+    platform_label="macOS (Intel)"
+  fi
+else
+  if [ "$arch" = "aarch64" ]; then
+    npm_tag="linux-arm64"
+    vendor_target="aarch64-unknown-linux-musl"
+    platform_label="Linux (ARM64)"
+  else
+    npm_tag="linux-x64"
+    vendor_target="x86_64-unknown-linux-musl"
+    platform_label="Linux (x64)"
+  fi
+fi
+
+if [ -x "$INSTALL_DIR/codex" ]; then
+  install_mode="Updating"
+else
+  install_mode="Installing"
+fi
+
+step "$install_mode Codex CLI"
+step "Detected platform: $platform_label"
+
+resolved_version="$(resolve_version)"
+asset="codex-npm-$npm_tag-$resolved_version.tgz"
+download_url="$(release_url_for_asset "$asset" "$resolved_version")"
+
+step "Resolved version: $resolved_version"
+
+tmp_dir="$(mktemp -d)"
+cleanup() {
+  rm -rf "$tmp_dir"
+}
+trap cleanup EXIT INT TERM
+
+archive_path="$tmp_dir/$asset"
+
+step "Downloading Codex CLI"
+download_file "$download_url" "$archive_path"
+
+tar -xzf "$archive_path" -C "$tmp_dir"
+
+step "Installing to $INSTALL_DIR"
+mkdir -p "$INSTALL_DIR"
+cp "$tmp_dir/package/vendor/$vendor_target/codex/codex" "$INSTALL_DIR/codex"
+cp "$tmp_dir/package/vendor/$vendor_target/path/rg" "$INSTALL_DIR/rg"
+chmod 0755 "$INSTALL_DIR/codex"
+chmod 0755 "$INSTALL_DIR/rg"
+
+add_to_path
+
+case "$path_action" in
+  added)
+    step "PATH updated for future shells in $path_profile"
+    step "Run now: export PATH=\"$INSTALL_DIR:\$PATH\" && codex"
+    step "Or open a new terminal and run: codex"
+    ;;
+  configured)
+    step "PATH is already configured for future shells in $path_profile"
+    step "Run now: export PATH=\"$INSTALL_DIR:\$PATH\" && codex"
+    step "Or open a new terminal and run: codex"
+    ;;
+  *)
+    step "$INSTALL_DIR is already on PATH"
+    step "Run: codex"
+    ;;
+esac
+
+printf 'Codex CLI %s installed successfully.\n' "$resolved_version"