diff --git a/src/fxhnt/application/combined_book_source.py b/src/fxhnt/application/combined_book_source.py
new file mode 100644
index 0000000..4f5f49c
--- /dev/null
+++ b/src/fxhnt/application/combined_book_source.py
@@ -0,0 +1,34 @@
+"""Data source for the combined book — the A→B seam. The book reads its crypto panel + futures series
+through this port; RawFileSource is the existing raw-file path, WarehouseSource (next task) reads the SSOT."""
+from __future__ import annotations
+
+from typing import Protocol
+
+import numpy as np
+
+from fxhnt.adapters.data.dbn_local import LocalDbnLoader
+from fxhnt.application.crypto_momentum_research import load_crypto_panel
+from fxhnt.domain.models import PriceSeries
+
+
+class CombinedBookSource(Protocol):
+    def crypto_panel(self) -> tuple[list[int], list[str], np.ndarray, np.ndarray]:
+        """(days, syms, close[d×s], ret[d×s]) — same shape as load_crypto_panel."""
+        ...
+
+    def futures_series(self, root: str) -> PriceSeries:
+        """Continuous front-month PriceSeries for a futures root."""
+        ...
+
+
+class RawFileSource:
+    def __init__(self, data_dir: str, crypto_subdir: str = "crypto_pit") -> None:
+        self._dir = data_dir
+        self._sub = crypto_subdir
+        self._loader = LocalDbnLoader()
+
+    def crypto_panel(self) -> tuple[list[int], list[str], np.ndarray, np.ndarray]:
+        return load_crypto_panel(f"{self._dir}/{self._sub}")
+
+    def futures_series(self, root: str) -> PriceSeries:
+        return self._loader.load(f"{self._dir}/{root}.dbn", root)
diff --git a/tests/unit/test_combined_book_source.py b/tests/unit/test_combined_book_source.py
new file mode 100644
index 0000000..d58e0e2
--- /dev/null
+++ b/tests/unit/test_combined_book_source.py
@@ -0,0 +1,14 @@
+"""CombinedBookSource: RawFileSource reproduces load_crypto_panel; WarehouseSource (next task) matches it."""
+from __future__ import annotations
+
+import numpy as np
+
+
+def test_raw_file_source_crypto_panel_matches_loader(tmp_path) -> None:
+    from fxhnt.application.combined_book_source import RawFileSource
+    cp = tmp_path / "crypto_pit"; cp.mkdir()
+    np.savez(cp / "BTCUSDT.npz", day=np.array([19000, 19001]), close=np.array([100.0, 110.0]))
+    np.savez(cp / "ETHUSDT.npz", day=np.array([19001]), close=np.array([50.0]))
+    days, syms, close, ret = RawFileSource(str(tmp_path)).crypto_panel()
+    assert days == [19000, 19001] and syms == ["BTCUSDT", "ETHUSDT"]
+    assert close[1, 0] == 110.0 and abs(ret[1, 0] - 0.10) < 1e-12