Differences from v1

This page is for merchants who used the previous size widget (Fitle, "v1" here). FitMyType keeps the same attributes, events and answer shapes, so most of your code stays. But the names and hosts change, and there is no drop-in replacement: an existing Fitle script keeps calling the old hosts until you change it.

Names and hosts to change

Before	Now	Where
`<fitle-size-recommender>`	`<fmt-size-recommender>`	Product page element
`https://recommender.fitle.com/sr.js`	`https://recommender.fitmytype.com/sr.js`	Element loader script
`https://sdk.fitle.com/sdk.js`	`https://sdk.fitmytype.com/sdk.js`	SDK script
`https://recommender.fitle.com/ftltag.js`	`https://recommender.fitmytype.com/fmttag.js`	Tracking tag script
`https://recommender.fitle.com/shopify-theme.js`	`https://recommender.fitmytype.com/shopify-theme.js`	Shopify theme helper
`window.Fitle`	`window.FitMyType`	SDK global
`ftltag`	`fmttag`	Tag function
`ftldataLayer`	`fmtdataLayer`	Tag queue
`ftl_device_id`	`fmt_device_id`	Device id in the browser (copied for you, see below)
`ftlWidgetEnd`	`fmtWidgetEnd`	Widget event
`ftlAutoRecommendation`	`fmtAutoRecommendation`	Widget event
`https://api.fitle.com`	`https://api.fitmytype.com`	API host
`https://admin.fitle.com`	`https://admin.fitmytype.com`	Back-office
`/v2/… and /v3/… API paths`	`/v1/…`	Every public API path

Every public path is /v1

Every public API path now starts with /v1: for example /v3/reco/clothes is /v1/reco/clothes and /v2/plugins/customization is /v1/plugins/customization. The old paths are not kept. The request and answer bodies keep their shape. The event intake stays at /events. See the API reference.

The device id moves over by itself

When a shopper who had ftl_device_id in their browser first loads the new widget (after analytics consent), it is copied into fmt_device_id, so their history continues. You do nothing.

What else changed

Setup has 4 steps: Feeds, Widget, Events, Verify (see Setup in 4 steps).
fmttag('config', …) takes an object with clientId, shopCountry and channel; the short form with the client ID alone still works (see Tag events).
The tag stub is window.fmttag = window.fmttag || … with window. on both sides: the old form without it fails when the tag has not loaded.
total_price is a number, not a quoted string.
On Shopify only the pixel sends add to cart and orders: remove any tag cart or transaction_end calls from your theme.
tooltipPosition takes 7 values; the default is bottom-left.
Only English ships for now; every language code shows English until its language ships.