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Backtest and live — byte-identical, in 10 languages. A streaming-native, event-driven backtester built on the Wickra indicator core.

▶ Live demo: run a strategy in your browser and watch the equity curve build bar by bar — backtest-live.wickra.org · zero backend, the same engine this repository ships, compiled to WebAssembly.

Part of the Wickra ecosystem: the same data-driven core and ten-language binding surface also power wickra-exchange, wickra-terminal, wickra-screener, wickra-xray, wickra-radar, wickra-copilot and wickra-shazam.

The engine consumes the exact same wickra-core O(1) indicator kernels that power live Wickra, and a strategy is data (a JSON spec), not code — so a backtest and a live run over the same spec produce identical signals, across every Wickra language binding. The same engine, fed live instead of historical bars, becomes the live bot: backtest ≡ live, by construction.

The strategy spec can reference 495 wickra-core indicators by name — every backtestable scalar, candle, multi-output, pairwise, derivatives, order-book, trade, trade-quote and cross-section indicator, with multi-output fields addressed as "name.field" (macd.signal, bb.upper, adx.plus_di, …). The registry is generated directly from the wickra-core sources, so it stays in lock-step with the kernel.

pip install wickra-backtest

import wickra_backtest as wbt

spec = {                                  # a strategy is data, not code
    "symbol": "BTCUSDT", "timeframe": "1h",
    "indicators": {"fast": {"type": "Ema", "params": [12]},
                   "slow": {"type": "Ema", "params": [26]}},
    "entry": {"cross_above": ["fast", "slow"]},
    "exit":  {"cross_below": ["fast", "slow"]},
    "sizing": {"type": "fixed_fraction", "fraction": 0.95},
}

# Backtest: the whole series at once.
report = wbt.run(opens, highs, lows, closes, spec=spec)
print(report["metrics"]["return_pct"], report["metrics"]["sharpe"])

# Live: the same spec, the same engine, one bar at a time. Point `step` at a
# socket instead of an array and nothing else changes.
with wbt.StreamingBacktest(spec=spec) as live:
    for bar in feed:
        live.step(bar.open, bar.high, bar.low, bar.close)
        print(live.num_trades, live.latest_equity())
    report = live.finish()

The two reports are byte-identical. That is the whole claim, and a shared golden corpus holds every one of the ten bindings to it.

What it does differently:

• O(1) per tick — years of tick data in seconds, not hours (no recompute-on-every-tick).
• Backtest = live, value-identical across 10 languages — no reimplementation drift, pinned by a shared golden corpus for the OHLCV path and every microstructure feed.
• Microstructure backtesting — replay the order book, trades, perpetual funding and open interest as strategy inputs, not just OHLCV. Most Python backtesters have no place to put them.
• Realistic execution — long/short, market/limit/stop orders, leverage and position caps, five sizing models, intrabar stop-loss / take-profit / trailing stops, maker/taker fees, three slippage models, perpetual funding, liquidation and execution latency.
• Polyglot — the same StrategySpec runs from Rust, Python, Node.js, WASM, C, C++, C#, Go, Java and R.

Backtester	Languages	Engine	Strategy is	Book / funding inputs	Latest release
★ wickra-backtest	Rust · Python · Node.js · WASM · C · C++ · C# · Go · Java · R	event-driven, O(1)/bar	data (a JSON spec)	yes	unreleased
nautilus_trader	Rust · Python	event-driven	code	yes	2026-08
vectorbt	Python	vectorised	code	—	2026-07
backtesting.py	Python	vectorised	code	—	2026-07
zipline-reloaded	Python	event-driven	code	—	2025-07
backtrader	Python	event-driven	code	—	2023-04

Release dates are the latest published version on PyPI, checked when this table was written; "—" means the feed is not a first-class strategy input, not that the library is bad at what it does. nautilus_trader is the closest comparison and is ahead of this project in places — it is a full trading platform with live venue adapters, and it has shipped for years. The distinction here is narrower and worth stating plainly: a strategy is data rather than code, so the same spec runs unchanged from ten languages and a shared golden corpus pins every one of them to the same report, byte for byte. No other engine in this table offers that because none of them needs to.

Status

Alpha / work in progress. The engine, the data-driven StrategySpec, the full execution and cost model, the microstructure feeds and all ten language bindings are implemented and tested; a shared golden corpus pins the cross-language equality byte-for-byte. Not yet released to any registry.

Documentation

• Strategy spec reference — the full DSL: operands, conditions, sizing, costs, slippage, risk, execution and the report shape.
• Cookbook — six ready-to-run strategies (RSI mean reversion, MACD trend, Bollinger breakout, Donchian breakout, funding carry, order-book imbalance), each validated against the engine.
• Microstructure guide — backtesting on the order book, trades, perpetual funding and market breadth (the differentiator).
• Architecture — crates, data flow and design decisions.
• Benchmarks — throughput methodology and caveats.
• Examples — runnable specs and a sample dataset.
• The JSON Schema for the spec is at schema/strategy_spec.schema.json and is printed by wkbt schema.

Quickstart

A strategy is data — a JSON spec. Run one over a candle file with the wkbt CLI:

cargo run --bin wkbt -- run --data examples/sample.csv --spec examples/ema-cross.json

bars       80
trades     4
return     -2.68%
pnl        -268.21
sharpe     -0.186
max dd     2.68%
win rate   0.0%
fees       37.50

A spec declares named indicators and entry/exit rules over them:

{
  "symbol": "BTCUSDT", "timeframe": "1h",
  "indicators": { "ema_fast": { "type": "Ema", "params": [5] },
                  "ema_slow": { "type": "Ema", "params": [15] } },
  "entry": { "cross_above": ["ema_fast", "ema_slow"] },
  "exit":  { "cross_below": ["ema_fast", "ema_slow"] },
  "sizing": { "type": "fixed_fraction", "fraction": 0.95 },
  "risk": { "trailing_stop_pct": 5.0 }
}

See the cookbook and examples/ for complete strategies, and the spec reference for the full grammar.

From Rust, the same thing is wickra_backtest::run(&spec, &candles). For live use, StreamingBacktest::new(&spec, capital) then step(candle) per bar feeds the same engine one bar at a time — backtest and live are one code path. A single run_json request bundles candles, the spec and any feeds, and is the uniform entry point every binding wraps.

Run the same spec in any language

Every binding takes the same OHLCV arrays (or a run_json request) and JSON spec and returns the same report — byte-identical (a dict in Python). Each has a quickstart:

Binding	Install	Example
Rust	cargo add wickra-backtest	examples/rust
Python (PyO3)	pip install wickra-backtest	examples/python/backtest.py
Node.js (napi-rs)	npm install wickra-backtest	examples/node/backtest.js
Browser / WASM	npm install wickra-backtest-wasm	examples/wasm/backtest.cjs
C / C++ (C ABI)	header + library, see bindings/c	examples/c/streaming.c · cpp_smoke.cpp
C# (C ABI)	dotnet add package Wickra.Backtest, see bindings/csharp	examples/csharp
Go (cgo, C ABI)	go get github.com/wickra-lib/wickra-backtest-go, see bindings/go	examples/go
Java (FFM, C ABI)	Maven Central org.wickra:wickra-backtest, see bindings/java	examples/java
R (.Call, C ABI)	R CMD INSTALL bindings/r, see bindings/r	examples/r/backtest.R

Every example does the same thing in its own language: read the shared sample data, run the series both ways, and fail if the two reports differ. examples/README.md is the cross-language index.

The C, C++, C#, Go, Java and R bindings all call through the same C ABI hub; the golden corpus asserts every language produces the same report, for both the plain OHLCV path and the order-book / trade / derivatives / cross-section feed paths.

Performance

O(1) per bar — about 1.7M bars/second on one core (a year of 1-minute bars in ~0.3 s). See BENCHMARKS.md for the methodology and caveats.

Project layout

wickra-backtest/
├── crates/
│   ├── wickra-backtest-core/   engine: spec DSL, registry, rules, execution, portfolio, metrics, report
│   ├── wickra-backtest-data/   loaders (CSV / JSON / JSONL / Parquet) + resampling + Renko/Kagi/PnF
│   ├── wickra-backtest/        facade crate (re-exports the engine + runners)
│   ├── wickra-backtest-cli/    the `wkbt` command-line backtester
│   └── wickra-backtest-bench/  criterion throughput benchmarks
├── bindings/
│   ├── python/   PyO3 + maturin          ├── csharp/  P/Invoke over the C ABI
│   ├── node/     napi-rs                 ├── go/      cgo over the C ABI
│   ├── wasm/     wasm-bindgen            ├── java/    FFM over the C ABI
│   ├── c/        C ABI (cdylib/staticlib + generated header)
│   └── r/        .Call over the C ABI
├── golden/       shared cross-language parity corpus (cases + feed requests)
├── schema/       generated JSON Schema for the strategy spec
├── examples/     runnable strategies + a sample dataset
├── docs/         strategy spec reference + cookbook
└── fuzz/         cargo-fuzz targets (nightly)

Building from source

# Rust core + tests + lints
cargo test --workspace --all-features
cargo clippy --workspace --all-targets --all-features -- -D warnings
cargo bench -p wickra-backtest-bench

# Python binding (requires a Rust toolchain + maturin)
cd bindings/python && maturin develop --release && pytest

# Node binding (requires @napi-rs/cli)
cd bindings/node && npm install && npm run build && npm test

# WASM binding (requires wasm-pack)
cd bindings/wasm && wasm-pack build --target nodejs --out-dir pkg && node --test tests/

# C ABI (cdylib + staticlib + generated header)
cargo build -p wickra-backtest-c --release

# C# binding (requires the .NET 8 SDK; links the C ABI above)
dotnet test bindings/csharp/Wickra.Backtest.Tests/Wickra.Backtest.Tests.csproj

# Go binding (requires a C compiler for cgo; links the C ABI above)
cd bindings/go && go test ./...

# Java binding (requires JDK 22+ and Maven; links the C ABI above)
mvn -f bindings/java test

# R binding (requires a C toolchain / Rtools; links the C ABI above)
WKBT_INC="$PWD/bindings/c/include" WKBT_LIB="$PWD/target/debug" R CMD INSTALL bindings/r

The Go, Java and R bindings load the C ABI shared library at run time; put target/debug (or target/release) on the library path. Fuzzing requires a nightly toolchain — see fuzz/; the same never-panic invariants are covered on stable by the property tests.

Testing

Every layer is covered; the commands are in Building from source.

• wickra-backtest-core — 113 unit tests: hand-computed round trips (entry at the next open, exit on the signal after it), every sizing model, the cost and slippage models, intrabar stops and liquidation, funding, the rule evaluator, bounded history, and the feed requirements a spec declares. Plus five integration suites: property tests, the shipped example specs, and the three golden runners (batch, streaming, and the microstructure requests).
• wickra-backtest-data — 17 unit tests over CSV, JSONL, JSON-array and Binance kline decoding, plus the resamplers.
• bindings/c — 12 Rust tests driving the ABI itself, including the streaming handle's lifecycle and every error path, so a null or finished handle is proven to be reported rather than dereferenced.
• bindings/python — 21 pytest cases: smoke, streaming, golden parity, completeness of the module and class surface, and the feed path.
• bindings/node — 19 node --test cases, same shape.
• bindings/wasm — 8 node --test cases against the built package.
• bindings/csharp — 15 xUnit cases. bindings/java — 15 JUnit cases. bindings/go — 15 go test cases. bindings/r — 3 script suites.
• fuzz/ — five targets covering the whole untrusted-input surface: the spec parser, the JSON request, the engine loop, the fill model and the data loader.

On top of those, all ten languages replay a shared, language-neutral golden corpus — four OHLCV cases and five microstructure requests in golden/ — and assert equality with the Rust reference report. Since the streaming work, each also replays the corpus one bar at a time and asserts the same report, so the claim that a backtest and a live loop agree is pinned per language rather than argued.

What "parity" means here, precisely. The reports are compared byte for byte, not to a tolerance. That is possible because every binding calls the same Rust engine — the arithmetic is not reimplemented anywhere — and because the indicators the corpus names use only IEEE-754 arithmetic, which every conforming platform rounds identically. It is not free, though: a spec can name any indicator in the core, and some of those call a transcendental from the platform's math library (ln, atan, exp and friends). No mainstream libm rounds those correctly, and implementations differ in the last bit — the sibling indicator library measured a one-ulp difference on 24 of 67 bars for a single indicator. A golden case built on one of those would have to compare to a relative tolerance instead. None currently does, and that is a property of the corpus worth keeping deliberately rather than by accident.

Requirements

The minimum supported version per language. The same engine kernel runs behind every binding; the C-ABI bindings that compile on install — Go (cgo) and R (.Call) — also need a C compiler, and Java runs with --enable-native-access=ALL-UNNAMED.

Language	Package	Minimum supported
Rust	crates.io · wickra-backtest	1.86 (MSRV)
Python	PyPI · wickra-backtest (abi3 wheel)	3.9 (tested through 3.13)
Node.js	npm · wickra-backtest (N-API 8)	22 (tested on 22 · 24 LTS)
WASM	npm · wickra-backtest-wasm	any modern JS engine
C	wickra_backtest.h + library (releases)	C99 compiler
C++	the C ABI + optional wickra_backtest.hpp	C++14 compiler
C#	NuGet · Wickra.Backtest	.NET 8 (net8.0)
Go	module · wickra-lib/wickra-backtest-go	Go 1.23 (cgo)
Java	Maven Central · org.wickra:wickra-backtest	Java 22 (FFM / Panama)
R	r-universe · wickrabacktest	R ≥ 2.10 (Rtools on Win.)

Ecosystem

Part of the Wickra family — each one a data-driven core with a CLI and the same ten-language binding surface:

• wickra — the core library: 514 O(1) streaming indicators across ten languages
• wickra-exchange — unified market-data + execution across ten crypto exchanges
• wickra-backtest — event-driven backtester over the Wickra core
• wickra-terminal — the trading terminal: a TUI and a browser renderer over the stack
• wickra-screener — parallel multi-symbol screening over 514 streaming indicators
• wickra-xray — market-microstructure explorer: footprint, order-book heatmap, liquidation map, funding/OI divergence
• wickra-radar — perp-universe alert radar: OI delta, funding flip, book imbalance, liquidation clusters, OI/price divergence
• wickra-copilot — local market copilot grounded in real order-book, liquidation and funding microstructure
• wickra-shazam — match an asset's current microstructure fingerprint against its entire history

This project's own site is backtest.wickra.org and its in-browser demo backtest-live.wickra.org. The indicator core it is built on documents itself at docs.wickra.org.

Contributing

Contributions are welcome — issues, bug reports, ideas and pull requests all land at https://github.com/wickra-lib/wickra-backtest. See CONTRIBUTING.md for the orientation: the engine lives in crates/wickra-backtest-core, every binding under bindings/<lang> keeps the golden-corpus parity invariant, and cargo fmt --all + cargo clippy --workspace --all-targets --all-features -- -D warnings are CI gates. For larger changes, open an issue first.

Security

Found a security issue? Please don't open a public issue. Report it privately via the repository's Security tab ("Report a vulnerability") or email support@wickra.org. Full policy: SECURITY.md.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option. Use it, fork it, modify it, redistribute it — commercially or not — file issues, send pull requests; all welcome.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Disclaimer

Not a trading system. Backtest results are deterministic transforms of the input data — they are not financial advice and are not indicative of future performance. Any use in a live trading context is at your own risk. The software is provided as is, without warranty of any kind; see the license files for the full terms.

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