Free · B4 Signal API v1 · NinjaTrader 8

Build indicators that speak B4.

The free B4 Signal API, three ready-to-learn demo indicators and the B4 NinjaTrader 8 skill library for AI-assisted development. Everything you need to publish entry and confirmation signals the B4 way.

Download the free kit ↓Read the API

OnBarUpdate()

// reset, then publish for the current bar
b4BuySignal[0]  = false;
b4SellSignal[0] = false;
b4ConfirmationDirection[0] = 0;

if (B4UseEntrySignals) {
    b4BuySignal[0]  = CrossAbove(fast, slow, 1);
    b4SellSignal[0] = CrossBelow(fast, slow, 1);
}
if (B4UseConfirmations)
    b4ConfirmationDirection[0] =
        fast[0] > slow[0] ? 1 : -1;

B4 Signal API v1

Five members. One clear contract.

Add these members to any NinjaTrader 8 indicator and its signals can be read by B4 tools and by any other NinjaScript, exactly like built-in indicator series. The API publishes signals only; it never places orders.

MemberTypeMeaning

B4UseEntrySignalsbool settingTurns entry signals on or off (default on)

B4UseConfirmationsbool settingTurns the confirmation series on or off (default on)

B4BuySignalsSeries<bool>true only on the bar that produced a buy signal

B4SellSignalsSeries<bool>true only on the bar that produced a sell signal

B4ConfirmationDirectionsSeries<int>1 long bias, -1 short bias, 0 none, for the current bar

Pulse, then reset

Reset every bar to false / false / 0, then publish. A signal is true only on the bar it happened.

Exact names, exact attributes

Tools match by name. Keep the types, the settings group "B4 CoPilot Pro Integration" and the empty setters.

Signals, never orders

API indicators publish information only. Execution stays with a strategy or tool the trader controls.

Full API guide Copy-paste API block (.cs)

Free demo projects

Three indicators to learn from.

Simple, readable NinjaScript written from scratch, each with the B4 Signal API built in. Every signal-affecting value is an adjustable setting.

B4ApiDemoEmaCross.cs

EMA Cross

A fast EMA crossing a slow EMA publishes buy and sell signals; the confirmation series reports the trend side.

Settings: fast period, slow period
Confirmation: 1 while fast > slow, -1 while below

Download .cs

B4ApiDemoRsiReversal.cs

RSI Reversal

RSI climbing back out of oversold publishes a buy; falling back out of overbought publishes a sell.

Settings: period, smoothing, oversold, overbought, midline
Confirmation: RSI above or below the midline

Download .cs

B4ApiDemoDonchianBreakout.cs

Donchian Breakout

A close beyond the previous N-bar channel publishes a breakout signal in that direction.

Settings: channel period
Confirmation: direction of the most recent breakout

Download .cs

Download all three demos (.zip)

B4 NinjaTrader 8 skill library

Teach your AI assistant to build NT8 the right way.

Seven skills for Claude Code and compatible AI coding tools. Each one turns hard-won NinjaTrader 8 engineering practice into a procedure, with templates and checklists.

Indicator Foundations

nt8-indicator-foundations

Lifecycle states, plots, Series<T>, properties, bar guards, Calculate modes, anti-repaint and hot-path performance, plus a starter template.

Use when: creating or editing any NT8 indicator.

B4 Signal API

nt8-b4-signal-api

Add the five-member B4 Signal API v1 to any indicator, with a copy-paste block and a test checklist.

Use when: an indicator should publish B4 entry and confirmation signals.

Adjustable Parameters

nt8-adjustable-parameters

No hard-wired trading values. Turn every threshold, period and offset into a setting without changing behaviour.

Use when: writing new code or removing magic numbers.

Build Verification

nt8-build-verification

Eight verification gates, real compiles, an error database and an honest build report. No "should work".

Use when: finishing any change, or a compile fails.

Drawing & Rendering

nt8-drawing-and-rendering

Draw.* overloads and tags, when to move to OnRender with SharpDX, resource lifetime and keeping visuals out of logic.

Use when: adding arrows, zones, labels or custom visuals.

Order Flow & Data

nt8-order-flow-and-data

OnMarketData trade classification, Tick Replay, Level II depth, multiple series and keeping real versus estimated order flow honest.

Use when: building footprint, delta, CVD, profile or DOM tools.

Safe Deployment

nt8-safe-deployment

Back up, deploy only when flat, understand the automatic compile, reload charts and keep a rollback path.

Use when: installing or updating NinjaScript on a live platform.

Download the skill library (.zip)

Install

Up and running in minutes.

Demo indicators (NinjaTrader 8)

Make sure you are flat, ideally with the market closed.
Copy the .cs file into Documents\NinjaTrader 8\bin\Custom\Indicators\.
Open the NinjaScript Editor and compile (F5); check for errors.
Add "B4 API Demo - ..." to a chart. The B4 settings sit under B4 CoPilot Pro Integration.

Skill library (Claude Code)

Unzip the library.
Copy a skill folder into %USERPROFILE%\.claude\skills\ for personal use, or .claude\skills\ inside a project.
Ask for NinjaTrader 8 work as usual; the matching skill loads automatically from its description.

The demos place no orders, read no account data and write no files. They are learning material, not trading systems. Community projects built with this kit are third-party work unless B4 reviews and supports them.