diff --git a/insto/cli.py b/insto/cli.py
index 80d0542..8df3bc4 100644
--- a/insto/cli.py
+++ b/insto/cli.py
@@ -27,6 +27,7 @@
 import asyncio
 import contextlib
 import getpass
+import importlib.util
 import logging
 import os
 import shlex
@@ -38,6 +39,7 @@
 
 from insto import __version__
 from insto._redact import redact_secrets
+from insto.backends import AIOGRAPI_INSTALL_HINT
 from insto.commands import (  # noqa: F401  — importing registers all commands
     COMMANDS,
     CommandUsageError,
@@ -77,6 +79,11 @@
 SETUP_HINT = "no HIKERAPI_TOKEN configured. Run `insto setup` to create one."
 
 
+def _is_aiograpi_installed() -> bool:
+    """Return whether the optional aiograpi backend dependency is importable."""
+    return importlib.util.find_spec("aiograpi") is not None
+
+
 # ---------------------------------------------------------------------------
 # Logging
 # ---------------------------------------------------------------------------
@@ -348,6 +355,8 @@ def _run_setup_non_interactive(*, out: IO[str] | None = None) -> int:
     if backend not in {BACKEND_HIKERAPI, BACKEND_AIOGRAPI}:
         print(f"--non-interactive: unknown backend {backend!r}", file=sys.stderr)
         return 2
+    if backend == BACKEND_AIOGRAPI and not _is_aiograpi_installed():
+        print(AIOGRAPI_INSTALL_HINT, file=stream)
 
     token = os.environ.get("HIKERAPI_TOKEN") or (existing.hiker_token if existing else None)
     proxy = os.environ.get("HIKERAPI_PROXY") or (existing.hiker_proxy if existing else None)
@@ -451,6 +460,8 @@ def _run_setup(
     if backend not in {BACKEND_HIKERAPI, BACKEND_AIOGRAPI}:
         print(f"unknown backend {backend!r}; falling back to hikerapi", file=stream)
         backend = BACKEND_HIKERAPI
+    if backend == BACKEND_AIOGRAPI and not _is_aiograpi_installed():
+        print(AIOGRAPI_INSTALL_HINT, file=stream)
 
     token_default = existing.hiker_token if existing else None
     if backend == BACKEND_HIKERAPI:
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 8e9601c..e10f757 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -45,7 +45,16 @@
 @pytest.fixture(autouse=True)
 def _isolated_home(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> Iterator[Path]:
     monkeypatch.setenv(cfgmod.CONFIG_HOME_ENV, str(tmp_path / ".insto"))
-    for var in (cfgmod.ENV_TOKEN, cfgmod.ENV_PROXY, cfgmod.ENV_OUTPUT_DIR, cfgmod.ENV_DB_PATH):
+    for var in (
+        "INSTO_BACKEND",
+        cfgmod.ENV_TOKEN,
+        cfgmod.ENV_PROXY,
+        cfgmod.ENV_OUTPUT_DIR,
+        cfgmod.ENV_DB_PATH,
+        cfgmod.ENV_AIOGRAPI_USERNAME,
+        cfgmod.ENV_AIOGRAPI_PASSWORD,
+        cfgmod.ENV_AIOGRAPI_TOTP,
+    ):
         monkeypatch.delenv(var, raising=False)
     yield tmp_path
     # Detach our log handlers to not bleed across tests.
@@ -300,6 +309,34 @@ def prompt(text: str) -> str:
     assert "https://hikerapi.com/tokens" in token_prompt
 
 
+def test_setup_aiograpi_warns_when_optional_dependency_missing(
+    monkeypatch: pytest.MonkeyPatch,
+    capsys: pytest.CaptureFixture[str],
+) -> None:
+    monkeypatch.setattr(cli_mod, "_is_aiograpi_installed", lambda: False)
+
+    rc = _run_setup(
+        prompt=_scripted_prompt(
+            [
+                "aiograpi",
+                "instag",
+                "secret",
+                "",
+                "",
+                "",
+                "",
+            ]
+        )
+    )
+
+    assert rc == 0
+    out = capsys.readouterr().out
+    assert "aiograpi backend requested" in out
+    assert "pipx inject insto aiograpi" in out
+    assert "insto[aiograpi]" in out
+    assert load_config().backend == "aiograpi"
+
+
 def test_setup_writes_hikerapi_backend_and_section() -> None:
     rc = _run_setup(prompt=_scripted_prompt(["", "tok-1234567890", "", "", ""]))
 
@@ -610,3 +647,20 @@ def test_setup_non_interactive_missing_token_fails(capsys: pytest.CaptureFixture
     rc = cli_mod.main(["setup", "--non-interactive"])  # no token in env or config
     assert rc == 2
     assert "HIKERAPI_TOKEN" in capsys.readouterr().err
+
+
+def test_setup_non_interactive_aiograpi_warns_when_optional_dependency_missing(
+    monkeypatch: pytest.MonkeyPatch,
+    capsys: pytest.CaptureFixture[str],
+) -> None:
+    monkeypatch.setattr(cli_mod, "_is_aiograpi_installed", lambda: False)
+    monkeypatch.setenv("INSTO_BACKEND", "aiograpi")
+    monkeypatch.setenv("AIOGRAPI_USERNAME", "instag")
+    monkeypatch.setenv("AIOGRAPI_PASSWORD", "secret")
+
+    rc = cli_mod.main(["setup", "--non-interactive"])
+
+    assert rc == 0
+    out = capsys.readouterr().out
+    assert "pipx inject insto aiograpi" in out
+    assert load_config().backend == "aiograpi"