forex-tester-custom-indicator-api

TypeScript types and runtime API for custom indicators in Forex Tester Online.

Install this package in a custom indicator project, extend Indicator, then build and upload the result to FTO.

Install

npm install forex-tester-custom-indicator-api

Write an indicator

Export a default class that extends Indicator. Implement OnInit and OnCalculate. The platform injects this.api before OnInit runs.

import {
  Indicator,
  IndexBuffer,
  InputNumber,
  InputEnum,
  MovingAverageType,
  OutputWindow,
  PenStyle,
  PlotType,
  PriceType,
} from 'forex-tester-custom-indicator-api'

export default class SimpleMovingAverage extends Indicator {
  private period!: InputNumber
  private maType!: InputEnum<MovingAverageType>
  private applyToPrice!: InputEnum<PriceType>
  private buffer!: IndexBuffer

  public OnInit(): void {
    this.api.SetIndicatorShortName('SMA')
    this.api.SetIndicatorOutputWindow(OutputWindow.CHART)

    this.period = this.api.CreateIntegerInput('Period', 14, 1, 500, 1)
    this.maType = this.api.CreateMATypeInput()
    this.applyToPrice = this.api.CreateApplyToPriceInput()

    this.buffer = this.api.CreateBuffer()
    this.api.SetPlotCount(1)
    this.api.CreatePlot(0, this.buffer, 'SMA', PlotType.LINE, PenStyle.SOLID, 1, '#2196F3')
  }

  public OnCalculate(index: number): void {
    if (index + this.period.value >= this.api.Bars()) {
      return
    }

    const value = this.api.GetMA(
      index,
      0,
      this.period.value,
      this.maType.value,
      this.applyToPrice.value,
      this.buffer.getValue(index + 1)
    )

    this.buffer.setValue(index, value)
  }
}

Lifecycle

| Method | Required | When it runs | | --- | --- | --- | | OnInit() | yes | Once, when the indicator is created | | OnCalculate(index) | yes | For each bar that needs a value. 0 is the current bar | | OnParamsChange() | no | After the user changes inputs | | OnHide() / OnShow() | no | When the indicator is hidden or shown | | OnDeinit() | no | When the indicator is removed | | OnToolButtonClick(toolName) | no | When an indicator tool button is clicked |

What this.api covers

• Plots and buffers — CreateBuffer, SetPlotCount, CreatePlot, and related style helpers
• Inputs — CreateIntegerInput, CreateDoubleInput, CreateEnumInput, CreateMATypeInput, CreateApplyToPriceInput, and other typed input helpers
• Chart data — Open, High, Low, Close, Volume, Time, Bars, Symbol, Timeframe
• Built-in indicators — GetMA, iRSI, iMACD, and other i* helpers
• Objects, dates, and account info — chart objects, FTODate, and account/testing helpers

TypeScript types in this package are the source of truth: use autocomplete on this.api and the exported enums.

Documentation

Full authoring guides, setup, and upload steps: FTO custom indicators docs.