Write the terminal, don’t just use it

from while25 import Indicator, Plot
from while25.inputs import Int

class Momentum(Indicator):
    id      = "momentum"
    label   = "Momentum"
    overlay = False                      # its own pane, below price
    inputs  = [Int("length", default=14, minimum=2)]
    plots   = [Plot("mom", color="#e0a34a")]

    def compute(self, ctx):
        n    = int(ctx.params.get("length", 14))
        rows = ctx.data.candles(ctx.instrument, ctx.interval, limit=n + 200)
        if len(rows) <= n:
            return None

        close = [float(r["close"]) for r in rows]
        # Warm-up bars have no value yet — NaN renders as a gap, 0 would be a lie.
        out   = [float("nan")] * n + [
            (close[i] / close[i - n] - 1) * 100 for i in range(n, len(close))
        ]

        self.times = [int(r["time"]) for r in rows]   # one timestamp per value
        return {"mom": out}

from while25 import Strategy, on

class Breakout(Strategy):
    id = "breakout"

    @on.bar("EQ:US:AAPL", interval="5m")
    def bar(self, ctx, bar):
        if bar["close"] > bar["open"] * 1.01:
            ctx.orders.buy(ctx.instrument, 1, stop_loss=bar["low"])

# indicators/zscore.py
from while25 import Indicator, Plot, Level
from while25.inputs import Int

class ZScore(Indicator):
    id      = "zscore"
    label   = "Z-Score"
    overlay = False                       # its own pane, below price
    inputs  = [Int("length", default=20, minimum=2, maximum=500)]
    plots   = [Plot("z", color="#e0a34a")]
    levels  = [Level(2.0, style="dashed"), Level(-2.0, style="dashed")]

    def compute(self, ctx):
        n    = int(ctx.params.get("length", 20))
        rows = ctx.data.candles(ctx.instrument, ctx.interval, limit=n + 300)
        if len(rows) < n:
            return None

        close, out = [float(r["close"]) for r in rows], []
        for i in range(len(close)):
            if i < n - 1:
                out.append(float("nan"))          # warm-up renders as a gap
                continue
            w    = close[i - n + 1:i + 1]
            mean = sum(w) / n
            sd   = (sum((x - mean) ** 2 for x in w) / n) ** 0.5
            out.append(0.0 if sd == 0 else (close[i] - mean) / sd)

        self.times = [int(r["time"]) for r in rows]   # one per value
        return {"z": out}

from while25 import Strategy, on

class Breakout(Strategy):
    id = "breakout"

    @on.tick("EQ:US:AAPL")
    def price(self, ctx, tick):
        ...

    @on.fill(tag="breakout")
    def filled(self, ctx, event):
        ...

from while25 import While25Error

try:
    res = ctx.orders.bracket("FUT:US:MNQ:202609", "BUY", 1,
                             take_profit=21_450.0,
                             stop_loss=21_380.0,
                             tag="breakout")
except While25Error as e:
    # A refusal RAISES — it does not come back as {"ok": False}. Risk-gate
    # rejections arrive here too.
    ctx.log(f"refused [{e.code}] {e.message}", level="error")
else:
    if res["paper"]:
        ctx.log("filled on the paper book")        # not armed for live
    else:
        ctx.log(f"live order {res['order_id']}")

ctx.viz.bar(trades, "P&L by symbol", x="symbol", y="pnl")
ctx.viz.heatmap(grid, "Correlation", x="a", y="b", value="rho")
ctx.viz.table(df, "Open positions")            # a DataFrame works directly

# apps/desk.py
from while25 import App, on
from while25 import ui

ui.panel("desk", "Trading Desk")
ui.layout(
    ui.row(ui.metric("pnl", "Day P&L"), ui.metric("pos", "Positions")),
    ui.chart("equity", "Equity curve"),
    ui.table("fills", "Recent fills"),
)

class Desk(App):
    id = "desk"

    @on.schedule(every="5s")
    def refresh(self, ctx):
        p = ctx.portfolio.snapshot()
        ctx.ui.push("pnl", p.get("day_pnl"))
        ctx.ui.push("pos", len(ctx.portfolio.positions()))

<workspace>/
├── indicators/  strategies/  monitors/  apps/   your modules
├── data/        files you drop in
├── lib/         packages you install
└── requirements.txt

from while25 import While25Error

try:
    rows = ctx.data.candles("EQ:US:AAPL", "5m", limit=200)
except While25Error as e:
    if e.code == "NO_SERIES":
        ctx.log("not being watched yet — open it on a chart")
        return
    raise                       # anything else is not ours to swallow