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Glossary
Terms that appear in the documentation, organized alphabetically.
Action - String that identifies the intent of an order. The 7 canonical actions: buy_to_open, sell_short_to_open, sell_to_close, buy_to_cover, close_position, reverse_position, update_position_exits. See Canonical actions table.
Admission control - Backend subsystem that applies safety limits to prevent abuse. Returns HTTP 429 when a limit is exceeded.
Backtest - Replay of a strategy against historical data. Processes thousands of candles in seconds. Deterministic. Generates quantitative metrics. See Reading the results.
Bracket order - Type of compound order: entry plus stop and target in OCO (one cancels the other). See Order types.
Candle - Dictionary with time, open, high, low, close, volume. Fundamental data unit. sdk.candles is the list of them.
Chart Trading - TessTrade live execution context. Runs the script against a real candle stream from the connected exchange, paper trading with a simulated account.
Cooldown - Pattern of waiting N seconds or bars after a signal before emitting the next one. Implemented manually in sdk.state with timestamps.
Crossover - Event in which one series transitions from below to above (or vice versa) another. Canonical operators: crosses_above, crosses_below.
DECLARATION - Root-level dictionary in the script that describes inputs, plots, pane and canonical conditions. See DECLARATION shape.
df - The main(df=...) parameter. A pd.DataFrame with columns time, open, high, low, close, volume. Used by the plot branch.
Dispatcher - Name of the main() function with 3 branches. Dispatches to on_bar_strategy (sdk=), _build_chart (df=) or returns the DECLARATION (no args).
Drawdown (DD) - Maximum drop of equity from a peak. Max DD is the worst observed valley. Risk metric.
EMA - Exponential Moving Average. Exponentially weighted moving average. See Implementing SMA and EMA.
Entry conditions / Exit conditions - DECLARATION fields that define declarative rules. Alternative to on_bar_strategy. See When to use entry/exit conditions.
Equity - Total account capital: cash plus market value of positions. sdk.equity exposes this value.
Feed - Real-time stream of candles/ticks from the connected exchange.
Histogram (plot) - Plot type with vertical bars. Common for MACD hist and volume.
Hook (legacy) - Alternative function to main(): on_bar(sdk). Less recommended; prefer main().
Imperative (mode) - Logic written in on_bar_strategy(sdk, params). Opposite of declarative mode. See The main() dispatcher.
Indicator - Script with DECLARATION["type"] = "indicator". Draws only plots; does not emit orders.
Input - Editable parameter declared in DECLARATION["inputs"]. Rendered as a control in the UI.
Level - Fixed horizontal line on the plot (e.g., 70/30 on RSI). Declared in DECLARATION["levels"].
Limit order - Order that executes only at the specified price or better. Kwarg order_type="limit" plus price=....
Live - Synonym for Chart Trading; execution against real-time data.
Look-ahead bias - Common backtest error: use of future data for a present decision. Generates unrealistic metrics that are not reproducible live.
MACD - Moving Average Convergence Divergence. Composite indicator: EMA(fast) minus EMA(slow), signal line and histogram.
Market order - Order executed immediately at the current price. Kwarg order_type="market". Default.
Max Positions - Limit of simultaneously open positions per account. Default 1 (no pyramiding).
OCO (One-Cancels-Other) - Pair of orders in which execution of one cancels the other. Used in brackets (stop and target).
on_bar(sdk) - Legacy entry point without a dispatcher. Works, but prefer main().
on_bar_strategy - Naming convention for the function called by the sdk= branch of main(). It is just a helper, with no special handling.
Overlay (pane) - Plot drawn over the price chart (on top of the candles). Used for moving averages, bands and VWAP.
Pane - Visual panel of the chart. "overlay" on top of price; "new" in a separate panel below. See panes.
PARAMS - Global variable injected by the engine with the values of the inputs. Used in legacy mode on_bar(sdk). In main() mode, use params or sdk.params.
Plot - Line, histogram or mark on the chart. Declared in DECLARATION["plots"]. Data comes in series.
Profit Factor (PF) - Sum of profits divided by sum of losses. PF > 1 indicates profitable; PF 1.5 or higher is good.
RSI - Relative Strength Index. Oscillator from 0 to 100. 70 indicates overbought; 30, oversold.
Sandbox - Isolated environment in which the Python script runs. Limits imports, builtins, CPU, memory and I/O access.
sdk - Object injected into the script with properties (candles, position, state, ...) and methods (buy, sell, close).
sdk.state - Persistent dictionary between calls. Used for flags, cooldown, manual trailing stop and buffers.
Sharpe Ratio - Return divided by volatility, multiplied by sqrt(252). Risk-adjusted return metric. Sharpe > 1 is good; > 2 is excellent.
Signal - Dictionary emitted by the SDK when sdk.buy/sell/close is called. Contains fields such as time, side, action, qty. Collected by the engine and executed.
Sizing - Determination of position size. qty= is absolute; size_pct= is relative to cash.
Slippage - Difference between expected and executed price. In backtest it is configurable; live it is real.
SMA - Simple Moving Average. Arithmetic mean of the last N closes.
Source (plot/condition) - Key that references a series in series. E.g., plot.source = "ma_fast" points to series["ma_fast"].
Stop loss - Forced exit price in case of loss. Kwarg stop_loss=.
Stop order - Order that activates (as market) when price crosses a trigger. Kwarg order_type="stop".
Strategy - Script with DECLARATION["type"] = "strategy". Emits orders and, optionally, draws plots.
Take profit - Exit price at profit. Kwarg take_profit=.
Target (condition) - In an entry/exit condition, the other series (or constant) against which the source is compared. Required, or value.
TIF (Time In Force) - Time during which the order stays alive: "day", "gtc", "ioc", "fok", "gtd".
Trailing stop - Stop that follows the price: rises with it in long, drops in short. Implemented manually via update_exits plus sdk.state.
Warmup - Initial period in which indicators do not yet have enough data. Return None in the series or exit early in the script. Size depends on the indicator (SMA-14 requires 14 or more candles).
Win rate - Percentage of profitable trades. In isolation it is misleading; combine with profit factor.
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