sabia 0.4.0

Polars-native technical features for trading pipelines — pure, point-in-time, online-ready

sabia

Polars-native technical features for trading pipelines — pure, point-in-time, online-ready.

sabia reads price/volume into features, grounded in the trading & finance literature. It is the features brick in a layered stack:

marketgoblin (data in) → sabia (features) → quale (signals)

Runtime dependencies are just polars and numpy. (The stack's calendar brick quando will be wired in when calendar-aware seasonality or the microstructure tier needs it — v1 seasonality is pure vectorized datetime.) Risk/eval math lives in ruin; signals live in quale. sabia computes features and nothing else.

What it is

Pure factories over OHLCV bars. A factory binds its params and returns a BoundFeature — an immutable .spec plus a .expr(schema) -> pl.Expr that resolves column roles (close@tr, high@split) against a caller-supplied BarSchema. Features are strictly trailing, point-in-time correct, and deterministic. Batch-first, online-ready: nothing streams in v1, but every feature declares the history it needs and is covered by a windowed-recompute parity test, so a future online engine is a thin wrapper rather than a rewrite.

Install

uv sync --extra dev

Quickstart

A complete, copy-paste-runnable example — two symbols, 30 daily bars, three features:

import math
import polars as pl
import sabia
from sabia import BarSchema

def bars(symbol, base):
    rets = [0.012 if i % 3 else -0.008 for i in range(30)]   # deterministic, varied
    close, c = [], base
    for r in rets:
        c *= math.exp(r); close.append(c)
    return pl.DataFrame({
        "timestamp": pl.datetime_range(pl.datetime(2024, 1, 1), pl.datetime(2024, 1, 30),
                                       interval="1d", time_zone="UTC", eager=True),
        "symbol": [symbol] * 30,
        "open":  [x * 0.999 for x in close],
        "high":  [x * 1.004 for x in close],
        "low":   [x * 0.996 for x in close],
        "close": close,
        "volume": [1_000_000.0 + 1000 * i for i in range(30)],
    })

frame = pl.concat([bars("AAA", 100.0), bars("BBB", 50.0)]).sort("symbol", "timestamp")

# BarSchema maps your physical columns to roles. sabia adjusts nothing — you declare which
# adjustment basis each column carries. .ohlcv(...) is the shorthand for the common OHLCV case;
# for richer inputs (a separate total-return close, VWAP, a market factor) build BarSchema(roles=...).
schema = BarSchema.ohlcv()   # open/high/low/close/volume; close also backs close@tr

# Factories return BoundFeature objects; compute resolves their roles and materializes. include_keys
# prepends symbol/timestamp, aligned row-for-row, which is what a downstream pipeline wants.
features = sabia.compute(
    frame,
    sabia.returns.ret_log(period=1),
    sabia.momentum.roc(window=5),
    sabia.volatility.vol_cc(window=10),
    schema=schema,
    include_keys=True,
)
print(features.tail(5))

shape: (5, 5)
┌────────┬─────────────────────────┬───────────┬──────────┬───────────┐
│ symbol ┆ timestamp               ┆ ret_log_1 ┆ roc_5    ┆ vol_cc_10 │
│ ---    ┆ ---                     ┆ ---       ┆ ---      ┆ ---       │
│ str    ┆ datetime[μs, UTC]       ┆ f64       ┆ f64      ┆ f64       │
╞════════╪═════════════════════════╪═══════════╪══════════╪═══════════╡
│ BBB    ┆ 2024-01-26 00:00:00 UTC ┆ 0.012     ┆ 0.020201 ┆ 0.009661  │
│ BBB    ┆ 2024-01-27 00:00:00 UTC ┆ 0.012     ┆ 0.040811 ┆ 0.009661  │
│ BBB    ┆ 2024-01-28 00:00:00 UTC ┆ -0.008    ┆ 0.020201 ┆ 0.010328  │
│ BBB    ┆ 2024-01-29 00:00:00 UTC ┆ 0.012     ┆ 0.020201 ┆ 0.009661  │
│ BBB    ┆ 2024-01-30 00:00:00 UTC ┆ 0.012     ┆ 0.040811 ┆ 0.009661  │
└────────┴─────────────────────────┴───────────┴──────────┴───────────┘

Each feature emits null during its warm-up window (a rolling stat needs a full window first); use sabia.drop_warmup(...) to trim those rows. Query the shipped catalog by horizon or data tier:

reg = sabia.Registry.default()
reg.where(lambda s: sabia.Horizon.MEDIUM in s.native_band)
reg.available(sabia.DataTier.DAILY)

Invariants

Causality · point-in-time correctness · purity (no I/O, clocks, randomness) · Polars-native (no pandas) · determinism within a declared tolerance. All enforced by tests, not convention. See FEATURES.md for the full spec.

Reproducibility & versioning

sabia pins polars==1.39.3 exactly and targets Python ≥ 3.13 on purpose: the manifest's feature fingerprint (§3.4) folds in the Polars version, so a stored dataset's exact feature definitions stay provable across train and serve. These pins are deliberate, not an oversight — they will relax toward a range once the fingerprint contract is settled past 1.0.

The fingerprint is a best-effort reproducibility hash, not a behavioral guarantee: it hashes each feature's bound params, roles, dependencies, the Polars version, and the normalized source of its expression (and first-party helpers). That catches the changes that matter in practice — a retuned constant, a swapped role, an edited formula — but, being source-based, two mathematically equivalent rewrites can still produce different fingerprints. Treat a fingerprint change as "prove this was intended" (the CI manifest gate enforces exactly that), not as a proof of behavioral difference. FeatureSetManifest serializes (to_json / from_json) so a dataset can carry its definitions.

License

MIT