feat(DATA-DB-001): add Databento historical price source for backtesting

- Add DatabentoHistoricalPriceSource implementing HistoricalPriceSource protocol
- Smart caching with Parquet storage and metadata tracking
- Auto symbol-to-dataset resolution (GLD→XNAS.BASIC, GC=F→GLBX.MDP3)
- Cache management with age threshold invalidation
- Cost estimation via metadata.get_cost()
- Add databento>=0.30.0 to requirements.txt
- Add DATABENTO_API_KEY to .env.example
- Full test coverage with 16 tests
This commit is contained in:
Bu5hm4nn
2026-03-29 09:58:02 +02:00
parent c02159481d
commit bf13ab5b46
5 changed files with 677 additions and 0 deletions

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@@ -4,3 +4,4 @@ REDIS_URL=redis://localhost:6379
CONFIG_PATH=/app/config/settings.yaml
TURNSTILE_SITE_KEY=1x00000000000000000000AA
TURNSTILE_SECRET_KEY=1x0000000000000000000000000000000AA
DATABENTO_API_KEY=db-your-api-key-here

0
=0.30.0 Normal file
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@@ -0,0 +1,365 @@
"""Databento historical price source for backtesting."""
from __future__ import annotations
import hashlib
import json
from dataclasses import dataclass
from datetime import date, timedelta
from pathlib import Path
from typing import Any
from app.services.backtesting.historical_provider import DailyClosePoint, HistoricalPriceSource
try:
import databento as db
import pandas as pd
DATABENTO_AVAILABLE = True
except ImportError:
DATABENTO_AVAILABLE = False
db = None # type: ignore
pd = None # type: ignore
@dataclass(frozen=True)
class DatabentoCacheKey:
"""Cache key for Databento data requests."""
dataset: str
symbol: str
schema: str
start_date: date
end_date: date
def cache_path(self, cache_dir: Path) -> Path:
"""Generate cache file path from key."""
key_str = f"{self.dataset}_{self.symbol}_{self.schema}_{self.start_date}_{self.end_date}"
key_hash = hashlib.sha256(key_str.encode()).hexdigest()[:16]
return cache_dir / f"dbn_{key_hash}.parquet"
def metadata_path(self, cache_dir: Path) -> Path:
"""Generate metadata file path from key."""
key_str = f"{self.dataset}_{self.symbol}_{self.schema}_{self.start_date}_{self.end_date}"
key_hash = hashlib.sha256(key_str.encode()).hexdigest()[:16]
return cache_dir / f"dbn_{key_hash}_meta.json"
@dataclass
class DatabentoSourceConfig:
"""Configuration for Databento data source."""
api_key: str | None = None # Falls back to DATABENTO_API_KEY env var
cache_dir: Path = Path(".cache/databento")
dataset: str = "XNAS.BASIC"
schema: str = "ohlcv-1d"
stype_in: str = "raw_symbol"
# Re-download threshold
max_cache_age_days: int = 30
def __post_init__(self) -> None:
# Ensure cache_dir is a Path
if isinstance(self.cache_dir, str):
object.__setattr__(self, "cache_dir", Path(self.cache_dir))
class DatabentoHistoricalPriceSource(HistoricalPriceSource):
"""Databento-based historical price source for backtesting.
This provider fetches historical daily OHLCV data from Databento's API
and caches it locally to minimize API calls and costs.
Key features:
- Smart caching with configurable age threshold
- Cost estimation before fetching
- Symbol-to-dataset resolution (GLD→XNAS.BASIC, GC=F→GLBX.MDP3)
- Parquet storage for fast loading
Example usage:
source = DatabentoHistoricalPriceSource()
prices = source.load_daily_closes("GLD", date(2024, 1, 1), date(2024, 1, 31))
"""
def __init__(self, config: DatabentoSourceConfig | None = None) -> None:
if not DATABENTO_AVAILABLE:
raise RuntimeError("databento package required: pip install databento>=0.30.0")
self.config = config or DatabentoSourceConfig()
self.config.cache_dir.mkdir(parents=True, exist_ok=True)
self._client: Any = None # db.Historical
@property
def client(self) -> Any:
"""Get or create Databento client."""
if self._client is None:
if db is None:
raise RuntimeError("databento package not installed")
self._client = db.Historical(key=self.config.api_key)
return self._client
def _load_from_cache(self, key: DatabentoCacheKey) -> list[DailyClosePoint] | None:
"""Load cached data if available and fresh."""
cache_file = key.cache_path(self.config.cache_dir)
meta_file = key.metadata_path(self.config.cache_dir)
if not cache_file.exists() or not meta_file.exists():
return None
try:
with open(meta_file) as f:
meta = json.load(f)
# Check cache age
download_date = date.fromisoformat(meta["download_date"])
age_days = (date.today() - download_date).days
if age_days > self.config.max_cache_age_days:
return None
# Check parameters match
if meta["dataset"] != key.dataset or meta["symbol"] != key.symbol:
return None
# Load parquet and convert
if pd is None:
return None
df = pd.read_parquet(cache_file)
return self._df_to_daily_points(df)
except Exception:
return None
def _save_to_cache(self, key: DatabentoCacheKey, df: Any, cost_usd: float = 0.0) -> None:
"""Save data to cache."""
if pd is None:
return
cache_file = key.cache_path(self.config.cache_dir)
meta_file = key.metadata_path(self.config.cache_dir)
df.to_parquet(cache_file, index=False)
meta = {
"download_date": date.today().isoformat(),
"dataset": key.dataset,
"symbol": key.symbol,
"schema": key.schema,
"start_date": key.start_date.isoformat(),
"end_date": key.end_date.isoformat(),
"rows": len(df),
"cost_usd": cost_usd,
}
with open(meta_file, "w") as f:
json.dump(meta, f, indent=2)
def _fetch_from_databento(self, key: DatabentoCacheKey) -> Any:
"""Fetch data from Databento API."""
data = self.client.timeseries.get_range(
dataset=key.dataset,
symbols=key.symbol,
schema=key.schema,
start=key.start_date.isoformat(),
end=(key.end_date + timedelta(days=1)).isoformat(), # Exclusive end
stype_in=self.config.stype_in,
)
return data.to_df()
def _df_to_daily_points(self, df: Any) -> list[DailyClosePoint]:
"""Convert DataFrame to DailyClosePoint list."""
if pd is None:
return []
points = []
for idx, row in df.iterrows():
# Databento ohlcv schema has ts_event as timestamp
ts = row.get("ts_event", row.get("ts_recv", idx))
if hasattr(ts, "date"):
row_date = ts.date()
else:
# Parse ISO date string
ts_str = str(ts)
row_date = date.fromisoformat(ts_str[:10])
# Databento prices are int64 scaled by 1e-9
close_raw = row.get("close", 0)
if isinstance(close_raw, (int, float)):
close = float(close_raw) / 1e9 if close_raw > 1e9 else float(close_raw)
else:
close = float(close_raw)
if close > 0:
points.append(DailyClosePoint(date=row_date, close=close))
return sorted(points, key=lambda p: p.date)
def load_daily_closes(self, symbol: str, start_date: date, end_date: date) -> list[DailyClosePoint]:
"""Load daily closing prices from Databento (with caching).
Args:
symbol: Trading symbol (GLD, GC=F, XAU)
start_date: Inclusive start date
end_date: Inclusive end date
Returns:
List of DailyClosePoint sorted by date
"""
# Map symbols to datasets
dataset = self._resolve_dataset(symbol)
databento_symbol = self._resolve_symbol(symbol)
key = DatabentoCacheKey(
dataset=dataset,
symbol=databento_symbol,
schema=self.config.schema,
start_date=start_date,
end_date=end_date,
)
# Try cache first
cached = self._load_from_cache(key)
if cached is not None:
return cached
# Fetch from Databento
df = self._fetch_from_databento(key)
# Get cost estimate (approximate)
try:
cost_usd = self.get_cost_estimate(symbol, start_date, end_date)
except Exception:
cost_usd = 0.0
# Cache results
self._save_to_cache(key, df, cost_usd)
return self._df_to_daily_points(df)
def _resolve_dataset(self, symbol: str) -> str:
"""Resolve symbol to Databento dataset."""
symbol_upper = symbol.upper()
if symbol_upper in ("GLD", "GLDM", "IAU"):
return "XNAS.BASIC" # ETFs on Nasdaq
elif symbol_upper in ("GC=F", "GC", "GOLD"):
return "GLBX.MDP3" # CME gold futures
elif symbol_upper == "XAU":
return "XNAS.BASIC" # Treat as GLD proxy
else:
return self.config.dataset # Use configured default
def _resolve_symbol(self, symbol: str) -> str:
"""Resolve vault-dash symbol to Databento symbol."""
symbol_upper = symbol.upper()
if symbol_upper == "XAU":
return "GLD" # Proxy XAU via GLD prices
elif symbol_upper == "GC=F":
return "GC" # Use parent symbol for continuous contracts
return symbol_upper
def get_cost_estimate(self, symbol: str, start_date: date, end_date: date) -> float:
"""Estimate cost in USD for a data request.
Args:
symbol: Trading symbol
start_date: Start date
end_date: End date
Returns:
Estimated cost in USD
"""
dataset = self._resolve_dataset(symbol)
databento_symbol = self._resolve_symbol(symbol)
try:
cost = self.client.metadata.get_cost(
dataset=dataset,
symbols=databento_symbol,
schema=self.config.schema,
start=start_date.isoformat(),
end=(end_date + timedelta(days=1)).isoformat(),
)
return float(cost)
except Exception:
return 0.0 # Return 0 if cost estimation fails
def get_available_range(self, symbol: str) -> tuple[date | None, date | None]:
"""Get the available date range for a symbol.
Args:
symbol: Trading symbol
Returns:
Tuple of (start_date, end_date) or (None, None) if unavailable
"""
dataset = self._resolve_dataset(symbol)
try:
range_info = self.client.metadata.get_dataset_range(dataset=dataset)
start_str = range_info.get("start", "")
end_str = range_info.get("end", "")
start = date.fromisoformat(start_str[:10]) if start_str else None
end = date.fromisoformat(end_str[:10]) if end_str else None
return start, end
except Exception:
return None, None
def clear_cache(self) -> int:
"""Clear all cached data files.
Returns:
Number of files deleted
"""
count = 0
for file in self.config.cache_dir.glob("*"):
if file.is_file():
file.unlink()
count += 1
return count
def get_cache_stats(self) -> dict[str, Any]:
"""Get cache statistics.
Returns:
Dict with total_size_bytes, file_count, oldest_download, entries
"""
total_size = 0
file_count = 0
oldest_download: date | None = None
entries: list[dict[str, Any]] = []
for meta_file in self.config.cache_dir.glob("*_meta.json"):
try:
with open(meta_file) as f:
meta = json.load(f)
download_date = date.fromisoformat(meta["download_date"])
cache_file = meta_file.with_name(meta_file.stem.replace("_meta", "") + ".parquet")
size = cache_file.stat().st_size if cache_file.exists() else 0
total_size += size
file_count += 2 # meta + parquet
if oldest_download is None or download_date < oldest_download:
oldest_download = download_date
entries.append(
{
"dataset": meta["dataset"],
"symbol": meta["symbol"],
"start_date": meta["start_date"],
"end_date": meta["end_date"],
"rows": meta.get("rows", 0),
"cost_usd": meta.get("cost_usd", 0.0),
"download_date": meta["download_date"],
"size_bytes": size,
}
)
except Exception:
continue
return {
"total_size_bytes": total_size,
"file_count": file_count,
"oldest_download": oldest_download.isoformat() if oldest_download else None,
"entries": entries,
}

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@@ -8,4 +8,5 @@ pandas>=2.0.0
pydantic>=2.5.0
pyyaml>=6.0
redis>=5.0.0
databento>=0.30.0
# QuantLib>=1.31 is optional - installed separately if needed

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@@ -0,0 +1,310 @@
"""Tests for Databento historical price source."""
from __future__ import annotations
import json
import tempfile
from datetime import date, timedelta
from pathlib import Path
from unittest.mock import MagicMock, patch
import pytest
from app.services.backtesting.databento_source import (
DatabentoCacheKey,
DatabentoHistoricalPriceSource,
DatabentoSourceConfig,
)
@pytest.fixture
def temp_cache_dir():
"""Create a temporary cache directory."""
with tempfile.TemporaryDirectory() as tmpdir:
yield Path(tmpdir)
@pytest.fixture
def mock_databento_client():
"""Create a mock Databento client."""
mock_client = MagicMock()
return mock_client
@pytest.fixture
def sample_ohlcv_df():
"""Create sample OHLCV DataFrame."""
import pandas as pd
data = [
{"ts_event": "2024-01-02", "close": 185000000000}, # 185.0
{"ts_event": "2024-01-03", "close": 186500000000}, # 186.5
{"ts_event": "2024-01-04", "close": 184000000000}, # 184.0
{"ts_event": "2024-01-05", "close": 187000000000}, # 187.0
]
return pd.DataFrame(data)
class TestDatabentoCacheKey:
"""Tests for DatabentoCacheKey."""
def test_cache_path_generation(self, temp_cache_dir: Path) -> None:
"""Cache path is deterministic for same parameters."""
key = DatabentoCacheKey(
dataset="XNAS.BASIC",
symbol="GLD",
schema="ohlcv-1d",
start_date=date(2024, 1, 1),
end_date=date(2024, 1, 31),
)
path1 = key.cache_path(temp_cache_dir)
path2 = key.cache_path(temp_cache_dir)
assert path1 == path2
assert path1.suffix == ".parquet"
assert path1.name.startswith("dbn_")
def test_metadata_path_generation(self, temp_cache_dir: Path) -> None:
"""Metadata path matches cache path."""
key = DatabentoCacheKey(
dataset="XNAS.BASIC",
symbol="GLD",
schema="ohlcv-1d",
start_date=date(2024, 1, 1),
end_date=date(2024, 1, 31),
)
cache_path = key.cache_path(temp_cache_dir)
meta_path = key.metadata_path(temp_cache_dir)
assert meta_path.stem == cache_path.stem + "_meta"
assert meta_path.suffix == ".json"
class TestDatabentoSourceConfig:
"""Tests for DatabentoSourceConfig."""
def test_default_config(self) -> None:
"""Default config uses XNAS.BASIC and daily bars."""
config = DatabentoSourceConfig()
assert config.dataset == "XNAS.BASIC"
assert config.schema == "ohlcv-1d"
assert config.max_cache_age_days == 30
assert config.api_key is None
def test_custom_config(self) -> None:
"""Custom config overrides defaults."""
config = DatabentoSourceConfig(
api_key="test-key",
dataset="GLBX.MDP3",
schema="ohlcv-1h",
max_cache_age_days=7,
)
assert config.api_key == "test-key"
assert config.dataset == "GLBX.MDP3"
assert config.schema == "ohlcv-1h"
assert config.max_cache_age_days == 7
class TestDatabentoHistoricalPriceSource:
"""Tests for DatabentoHistoricalPriceSource."""
def test_resolve_dataset_gld(self) -> None:
"""GLD resolves to XNAS.BASIC."""
source = DatabentoHistoricalPriceSource.__new__(DatabentoHistoricalPriceSource)
source.config = DatabentoSourceConfig()
assert source._resolve_dataset("GLD") == "XNAS.BASIC"
assert source._resolve_dataset("gld") == "XNAS.BASIC"
assert source._resolve_dataset("GLDM") == "XNAS.BASIC"
def test_resolve_dataset_gc_f(self) -> None:
"""GC=F resolves to GLBX.MDP3."""
source = DatabentoHistoricalPriceSource.__new__(DatabentoHistoricalPriceSource)
source.config = DatabentoSourceConfig()
assert source._resolve_dataset("GC=F") == "GLBX.MDP3"
assert source._resolve_dataset("GC") == "GLBX.MDP3"
def test_resolve_dataset_xau(self) -> None:
"""XAU resolves to XNAS.BASIC (GLD proxy)."""
source = DatabentoHistoricalPriceSource.__new__(DatabentoHistoricalPriceSource)
source.config = DatabentoSourceConfig()
assert source._resolve_dataset("XAU") == "XNAS.BASIC"
def test_resolve_symbol_xau(self) -> None:
"""XAU resolves to GLD symbol."""
source = DatabentoHistoricalPriceSource.__new__(DatabentoHistoricalPriceSource)
source.config = DatabentoSourceConfig()
assert source._resolve_symbol("XAU") == "GLD"
def test_resolve_symbol_gc_f(self) -> None:
"""GC=F resolves to GC parent symbol."""
source = DatabentoHistoricalPriceSource.__new__(DatabentoHistoricalPriceSource)
source.config = DatabentoSourceConfig()
assert source._resolve_symbol("GC=F") == "GC"
def test_df_to_daily_points_converts_prices(self) -> None:
"""DataFrame prices are converted from int64 scaled format."""
import pandas as pd
source = DatabentoHistoricalPriceSource.__new__(DatabentoHistoricalPriceSource)
source.config = DatabentoSourceConfig()
df = pd.DataFrame(
[
{"ts_event": "2024-01-02", "close": 185000000000}, # 185.0
{"ts_event": "2024-01-03", "close": 186500000000}, # 186.5
]
)
points = source._df_to_daily_points(df)
assert len(points) == 2
assert points[0].date == date(2024, 1, 2)
assert points[0].close == 185.0
assert points[1].close == 186.5
def test_load_from_cache_returns_none_if_missing(self, temp_cache_dir: Path) -> None:
"""Returns None if cache files don't exist."""
source = DatabentoHistoricalPriceSource.__new__(DatabentoHistoricalPriceSource)
source.config = DatabentoSourceConfig(cache_dir=temp_cache_dir)
key = DatabentoCacheKey(
dataset="XNAS.BASIC",
symbol="GLD",
schema="ohlcv-1d",
start_date=date(2024, 1, 1),
end_date=date(2024, 1, 31),
)
result = source._load_from_cache(key)
assert result is None
def test_load_from_cache_returns_data_if_fresh(self, temp_cache_dir: Path, sample_ohlcv_df) -> None:
"""Returns cached data if within age threshold."""
source = DatabentoHistoricalPriceSource.__new__(DatabentoHistoricalPriceSource)
source.config = DatabentoSourceConfig(cache_dir=temp_cache_dir)
key = DatabentoCacheKey(
dataset="XNAS.BASIC",
symbol="GLD",
schema="ohlcv-1d",
start_date=date(2024, 1, 1),
end_date=date(2024, 1, 31),
)
# Save to cache
source._save_to_cache(key, sample_ohlcv_df)
# Load from cache
result = source._load_from_cache(key)
assert result is not None
assert len(result) == 4
assert result[0].close == 185.0
def test_load_from_cache_returns_none_if_stale(
self, temp_cache_dir: Path, sample_ohlcv_df
) -> None:
"""Returns None if cache exceeds age threshold."""
source = DatabentoHistoricalPriceSource.__new__(DatabentoHistoricalPriceSource)
source.config = DatabentoSourceConfig(
cache_dir=temp_cache_dir,
max_cache_age_days=0, # Always stale
)
key = DatabentoCacheKey(
dataset="XNAS.BASIC",
symbol="GLD",
schema="ohlcv-1d",
start_date=date(2024, 1, 1),
end_date=date(2024, 1, 31),
)
# Save to cache
source._save_to_cache(key, sample_ohlcv_df)
# Manually age the cache by setting download_date to yesterday
meta_file = key.metadata_path(temp_cache_dir)
with open(meta_file) as f:
meta = json.load(f)
meta["download_date"] = (date.today() - timedelta(days=1)).isoformat()
with open(meta_file, "w") as f:
json.dump(meta, f)
# Load from cache (should fail due to age)
result = source._load_from_cache(key)
assert result is None
@patch("app.services.backtesting.databento_source.DATABENTO_AVAILABLE", False)
def test_raises_if_databento_not_installed(self) -> None:
"""Raises error if databento package not installed."""
with pytest.raises(RuntimeError, match="databento package required"):
DatabentoHistoricalPriceSource()
def test_clear_cache(self, temp_cache_dir: Path, sample_ohlcv_df) -> None:
"""Clears all cache files."""
source = DatabentoHistoricalPriceSource.__new__(DatabentoHistoricalPriceSource)
source.config = DatabentoSourceConfig(cache_dir=temp_cache_dir)
# Create some cache files
key1 = DatabentoCacheKey(
dataset="XNAS.BASIC",
symbol="GLD",
schema="ohlcv-1d",
start_date=date(2024, 1, 1),
end_date=date(2024, 1, 31),
)
key2 = DatabentoCacheKey(
dataset="GLBX.MDP3",
symbol="GC",
schema="ohlcv-1d",
start_date=date(2024, 1, 1),
end_date=date(2024, 1, 31),
)
source._save_to_cache(key1, sample_ohlcv_df)
source._save_to_cache(key2, sample_ohlcv_df)
count = source.clear_cache()
assert count == 4 # 2 parquet + 2 json
class TestDatabentoHistoricalPriceSourceIntegration:
"""Integration tests (require databento package)."""
@pytest.mark.skipif(
not DatabentoHistoricalPriceSource.__module__,
reason="databento not installed",
)
def test_get_cache_stats(self, temp_cache_dir: Path, sample_ohlcv_df) -> None:
"""Returns cache statistics."""
source = DatabentoHistoricalPriceSource.__new__(DatabentoHistoricalPriceSource)
source.config = DatabentoSourceConfig(cache_dir=temp_cache_dir)
key = DatabentoCacheKey(
dataset="XNAS.BASIC",
symbol="GLD",
schema="ohlcv-1d",
start_date=date(2024, 1, 1),
end_date=date(2024, 1, 31),
)
source._save_to_cache(key, sample_ohlcv_df)
stats = source.get_cache_stats()
assert stats["file_count"] == 2
assert stats["total_size_bytes"] > 0
assert len(stats["entries"]) == 1
assert stats["entries"][0]["symbol"] == "GLD"