diff --git a/README.md b/README.md
index b6d1692..6f88ae3 100644
--- a/README.md
+++ b/README.md
@@ -34,6 +34,19 @@ Then run:
 ourocode
 ```
 
+With no arguments, `ourocode` uses the current working directory as the project
+directory. Pass `--project-dir PATH` (or set `OUROCODE_PROJECT_DIR`) to point it
+elsewhere.
+
+### Requirements
+
+The bundled `ourocode` is an Erlang escript, so it needs the **Erlang/OTP
+runtime** (`escript`/`erl`) on your `PATH`. The installer installs it
+best-effort (Homebrew on macOS, `apt`/`dnf` on Linux); if that is not possible
+it stops with manual instructions. Install it yourself with `brew install
+erlang`, `sudo apt-get install erlang`, or `sudo dnf install erlang`. Set
+`OUROCODE_SKIP_ERLANG=1` to bypass the check.
+
 Optional model backends:
 
 - Claude CLI
@@ -96,7 +109,7 @@ curl -fsSL https://raw.githubusercontent.com/Q00/ourocode/release/bootstrap/inst
 ourocode
 ```
 
-`install.sh` downloads the matching GitHub Release tarball, installs `ourocode` into `~/.local/ourocode/<version>`, and writes a launcher at `~/.local/bin/ourocode`. The launcher sets `OUROCODE_TTY` so the installed escript can find the bundled native tty helper.
+`install.sh` downloads the matching GitHub Release tarball, installs `ourocode` into `~/.local/ourocode/<version>`, and writes a launcher at `~/.local/bin/ourocode`. The launcher sets `OUROCODE_TTY` so the installed escript can find the bundled native tty helper. It also ensures the Erlang/OTP runtime is available (see [Requirements](#requirements)), since the escript cannot run without it.
 
 When run from a source checkout, the same installer uses bundled release binaries if present, or builds from source when needed. Set `OUROCODE_BUILD_FROM_SOURCE=1` to force a local build.
 
diff --git a/install.sh b/install.sh
index 237e856..86fb49d 100755
--- a/install.sh
+++ b/install.sh
@@ -75,6 +75,54 @@ download_release() {
   fi
 }
 
+ensure_erlang_runtime() {
+  # The bundled `ourocode` is an Erlang escript and needs the Erlang/OTP runtime
+  # (`escript`/`erl`) on PATH to run. Release tarballs do not bundle the runtime,
+  # so a fresh machine ends up with a working launcher that cannot start. Make
+  # the runtime present here (best effort, like the Ouroboros step) so the
+  # documented `ourocode` quick start works after install.
+  if command -v escript >/dev/null 2>&1; then
+    return 0
+  fi
+
+  if [ "${OUROCODE_SKIP_ERLANG:-0}" = "1" ]; then
+    echo "==> skipping Erlang runtime check (OUROCODE_SKIP_ERLANG=1)" >&2
+    return 0
+  fi
+
+  echo "==> Erlang runtime (escript) not found; ourocode needs it to run"
+
+  local os
+  os="$(uname -s | tr '[:upper:]' '[:lower:]')"
+
+  if command -v brew >/dev/null 2>&1; then
+    echo "    installing Erlang via Homebrew (best effort)"
+    if brew install erlang; then
+      brew link --overwrite erlang >/dev/null 2>&1 || true
+    fi
+  elif [ "$os" = "linux" ] && command -v apt-get >/dev/null 2>&1; then
+    echo "    installing Erlang via apt-get (best effort; may require sudo)"
+    sudo apt-get update -y >/dev/null 2>&1 || true
+    sudo apt-get install -y erlang >/dev/null 2>&1 || true
+  elif [ "$os" = "linux" ] && command -v dnf >/dev/null 2>&1; then
+    echo "    installing Erlang via dnf (best effort; may require sudo)"
+    sudo dnf install -y erlang >/dev/null 2>&1 || true
+  fi
+
+  if ! command -v escript >/dev/null 2>&1; then
+    echo "" >&2
+    echo "error: Erlang/OTP runtime not found and could not be installed automatically." >&2
+    echo "       ourocode is an Erlang escript and needs 'escript'/'erl' on PATH." >&2
+    echo "       Install Erlang, then re-run this installer:" >&2
+    echo "         macOS:         brew install erlang" >&2
+    echo "         Debian/Ubuntu: sudo apt-get install erlang" >&2
+    echo "         Fedora:        sudo dnf install erlang" >&2
+    echo "       Other platforms: https://www.erlang.org/downloads" >&2
+    echo "       (set OUROCODE_SKIP_ERLANG=1 to bypass this check)" >&2
+    exit 1
+  fi
+}
+
 echo "==> ourocode install"
 
 need_build=0
@@ -131,6 +179,11 @@ exec "$INSTALL_DIR/ourocode" "\$@"
 EOF
 chmod +x "$BIN_DIR/ourocode"
 
+# The launcher above runs an Erlang escript; make sure the runtime exists before
+# we try to invoke it (e.g. the `--detect` call below) or hand control back to
+# the user.
+ensure_erlang_runtime
+
 # Ourocode surfaces the Ouroboros capability graph. This step is best-effort
 # and can be skipped for lean installs or CI with OUROCODE_SKIP_OUROBOROS=1.
 OUROBOROS_INSTALL_URL="${OUROBOROS_INSTALL_URL:-https://raw.githubusercontent.com/Q00/ouroboros/main/scripts/install.sh}"
diff --git a/lib/ourocode/cli/startup_args.ex b/lib/ourocode/cli/startup_args.ex
index 518ce01..b873e62 100644
--- a/lib/ourocode/cli/startup_args.ex
+++ b/lib/ourocode/cli/startup_args.ex
@@ -7,7 +7,7 @@ defmodule Ourocode.CLI.StartupArgs do
   config/task parsers after startup-only flags are removed.
   """
 
-  @default_project_dir "/Users/jaegyu.lee/Project/ourocode"
+  @project_dir_env "OUROCODE_PROJECT_DIR"
   @project_dir_flags MapSet.new(["--project-dir", "--project", "-d"])
   @smoke_test_flags MapSet.new(["--smoke-test", "--smoke", "--verify"])
   @prompt_flags MapSet.new(["--prompt", "-p"])
@@ -87,10 +87,30 @@ defmodule Ourocode.CLI.StartupArgs do
   def parse(_args, _options), do: {:error, "CLI args must be a list"}
 
   @doc """
-  Returns the default implementation project directory for the launcher.
+  Returns the default project directory for the launcher.
+
+  Resolution order:
+
+    * the `OUROCODE_PROJECT_DIR` environment variable when it is set to a
+      non-empty value (expanded to an absolute path), otherwise
+    * the current working directory.
+
+  This keeps the documented `ourocode` (no `--project-dir`) quick-start working
+  on any machine instead of pointing at a build-time developer path.
   """
   @spec default_project_dir() :: String.t()
-  def default_project_dir, do: @default_project_dir
+  def default_project_dir do
+    case System.get_env(@project_dir_env) do
+      value when is_binary(value) ->
+        case String.trim(value) do
+          "" -> File.cwd!()
+          trimmed -> Path.expand(trimmed)
+        end
+
+      _ ->
+        File.cwd!()
+    end
+  end
 
   defp extract_startup_args(args, project_dir),
     do: extract_startup_args(args, project_dir, false, false, :text, [], [])
diff --git a/test/ourocode/cli_test.exs b/test/ourocode/cli_test.exs
index ebcfd4a..754b480 100644
--- a/test/ourocode/cli_test.exs
+++ b/test/ourocode/cli_test.exs
@@ -74,9 +74,19 @@ defmodule Ourocode.CLITest do
 
   import ExUnit.CaptureIO
 
-  test "startup resolves the fixed implementation project directory" do
-    assert Ourocode.CLI.resolve_project_dir() ==
-             {:ok, "/Users/jaegyu.lee/Project/ourocode"}
+  test "startup resolves the current working directory by default" do
+    assert Ourocode.CLI.resolve_project_dir() == {:ok, File.cwd!()}
+  end
+
+  test "startup honors the OUROCODE_PROJECT_DIR override" do
+    System.put_env("OUROCODE_PROJECT_DIR", File.cwd!())
+
+    try do
+      assert Ourocode.CLI.resolve_project_dir(StartupArgs.default_project_dir()) ==
+               {:ok, File.cwd!()}
+    after
+      System.delete_env("OUROCODE_PROJECT_DIR")
+    end
   end
 
   test "startup argument parser separates launch args, config overrides, and task text" do
@@ -269,7 +279,7 @@ defmodule Ourocode.CLITest do
              Ourocode.CLI.main([], Ourocode.CLITest.DashboardSpy)
 
     assert_receive {:dashboard_init, ^context}
-    assert context.project_dir == "/Users/jaegyu.lee/Project/ourocode"
+    assert context.project_dir == File.cwd!()
     assert is_binary(context.cwd)
     assert context.initial_task_request == nil
     assert context.plugin_config.plugins |> Enum.map(& &1.id) == ["ouroboros-plugin"]