diff --git a/crdt-sync/crdt_sync/tests/test_tool_seeded_apps_kartka.py b/crdt-sync/crdt_sync/tests/test_tool_seeded_apps_kartka.py
new file mode 100644
index 0000000..d1b65c3
--- /dev/null
+++ b/crdt-sync/crdt_sync/tests/test_tool_seeded_apps_kartka.py
@@ -0,0 +1,59 @@
+# Copyright (c) 2026 Krzysztof Rudnicki
+"""kartka's two desktop sessions are seeded by one ``seed_session`` run.
+
+Split from :mod:`test_tool_seed_session_main` for the 250-line cap.
+"""
+
+from __future__ import annotations
+
+from datetime import UTC, datetime
+import json
+from pathlib import Path
+from unittest.mock import patch
+
+import pytest
+
+from crdt_sync._config import credential_store_for
+from crdt_sync._credentials import FirebaseCredentials
+from crdt_sync.tests.test_tool_seed_session import _CONFIG, _ID_VALUE
+from tool import google_id_token as git
+from tool import seed_session as ss
+
+_ARGV = ["--client-id", "the-web-client-id", "--client-secret", "the-secret"]
+_KARTKA = ("kartka-agent", "kartka-source-eval")
+
+
+def test_both_kartka_sessions_are_default_apps() -> None:
+    """The agent wrapper serves ``~/.config/kartka-agent/`` as
+    ``/sync-credentials``; the source evaluator reads
+    ``credential_store_for("kartka-source-eval")``."""
+    assert set(_KARTKA) <= set(ss.DEFAULT_APPS)
+
+
+def test_one_run_with_two_app_flags_seeds_both() -> None:
+    """``--app`` is repeatable, so one consent tap covers both."""
+    with (
+        patch.object(ss.FirebaseConfig, "load", return_value=_CONFIG),
+        patch.object(git, "fetch_id_token", return_value=_ID_VALUE),
+        patch.object(ss, "seed_apps", return_value=list(_KARTKA)) as seeded,
+    ):
+        code = ss.main([*_ARGV, "--app", _KARTKA[0], "--app", _KARTKA[1]])
+
+    assert code == 0
+    assert seeded.call_args.args[2] == _KARTKA
+
+
+@pytest.mark.parametrize("app", _KARTKA)
+def test_the_seed_lands_where_kartka_reads_it(app: str, tmp_path: Path) -> None:
+    """``~/.config/<app>/firebase_auth.json``, the path both readers use, in
+    the ``{id_token, refresh_token, expires_at}`` shape the wrapper serves."""
+    with patch.object(Path, "home", return_value=tmp_path):
+        credential_store_for(app).save(
+            FirebaseCredentials("fake-id", "fake-refresh", datetime.now(UTC))
+        )
+    written = tmp_path / ".config" / app / "firebase_auth.json"
+    assert set(json.loads(written.read_text())) == {
+        "id_token",
+        "refresh_token",
+        "expires_at",
+    }
diff --git a/crdt-sync/tool/_seeded_apps.py b/crdt-sync/tool/_seeded_apps.py
index 450243e..4ec499c 100644
--- a/crdt-sync/tool/_seeded_apps.py
+++ b/crdt-sync/tool/_seeded_apps.py
@@ -59,4 +59,12 @@ DEFAULT_APPS: Final = (
     # the Flutter client over RTDB (/sufler), headless, reading
     # ~/.config/sufler/firebase_auth.json via credential_store_for("sufler").
     "sufler",
+    # ~/src/kartka's headless agent instance (tools/agent): its wrapper serves
+    # this file once per launch as /sync-credentials, so the web build signs
+    # in with no password and no browser consent of its own.
+    "kartka-agent",
+    # ~/src/kartka/tools/source_eval: the weekly source evaluator publishes
+    # /kartka/source_health via credential_store_for("kartka-source-eval")
+    # and falls back to the retired password only with no session here.
+    "kartka-source-eval",
 )