Contract Errors

Every QSL strategy must export specific lifecycle functions. Contract errors are raised when required functions are missing.

Required Functions

Error: missing_define

Error: Strategy must export a define() function

Cause: Your code does not contain a function define(ctx) declaration.

Fix: Add a define() function, even if you have no parameters:

function define(ctx) {
  // No parameters needed for this strategy
}

Error: missing_onbar

Error: Strategy must export an onBar() function

Cause: Your code does not contain a function onBar(ctx, i) declaration.

Fix: Add your trading logic inside onBar():

function onBar(ctx, i) {
  // Your trading logic here
}

Warning: missing_init

Warning: Strategy does not export an init() function

init() is not strictly required, but without it you cannot declare indicators or initialise state. Most strategies need it.

function init(ctx) {
  ctx.indicator('sma', 'SMA', { period: ctx.p.period });
}

Function Naming

Functions must use these exact names. Common mistakes:

// Wrong — these will NOT be detected
function Define(ctx) { }     // uppercase D
function on_bar(ctx, i) { }  // underscore
function setup(ctx) { }      // wrong name
const onBar = (ctx, i) => {} // arrow function (may not be detected)

// Correct
function define(ctx) { }
function init(ctx) { }
function onBar(ctx, i) { }