How can the different TWINT issuers be called from my mobile app?

Preconditions

We check if the website is actually marked as mobile. Make sure you send an appropriate user agent in order for the app to open the mobile layout. This will make sure that the different TWINT Issuers are shown. 

How to invoke the Issuer Apps

All of these URLs are already being invoked by our payment page in case you send the correct user agent (see above). In case you wrap the payment page into your app you simply need to make sure that it's possible for these URLs (see below the list of Issuer) to go though and be invoked from within a web view. You don't need to worry about invoking them themselves. TWINT uses special URL schemes to invoke the App from payment web page. For Android the link is simply as follows:

intent://payment#Intent;action=ch.twint.action.TWINT_PAYMENT;scheme=twint;S.code={token};S.startingOrigin=EXTERNAL_WEB_BROWSER;S.browser_fallback_url=;end

The placeholder {token} indicates the place where we put the the payment code from TWINT.

For iOS, the link depends on the issuer bank. The base format is as follows:

twint-issuer1://applinks/?al_applink_data={"app_action_type": "TWINT_PAYMENT","extras": {"code": "{token}",},"referer_app_link": {"target_url": "", "url": "", "app_name": "EXTERNAL_WEB_BROWSER"}, "version": "6.0" }

The placeholder {token} again indicates the place where we put the the payment code from TWINT.

However, as mentioned, here the links are issuer specific, as unlike with android phones where simply an app will open which supports a given "intent", here we have to specify a particular app. In order to do that, we need to change the twint-issuer1:// prefix into one approppriate for the relevant bank's app.

List of TWINT Issuers

Here is the list of all prefixes for all supported banks:

AppKB twint-issuer12://
BCF twint-issuer16://
BCGE twint-issuer10://
BCJ twint-issuer17://
BCN twint-issuer18://
BCV twint-issuer5://
BCVs twint-issuer13://
Credit Suisse twint-issuer4://
GKB twint-issuer15://
Migrosbank twint-issuer21://
NAB twint-issuer11://
OKB twint-issuer8://
PostFinance twint-issuer7://
Raiffeisen twint-issuer6://
SGKB twint-issuer14://
TKB twint-issuer19://
TWINT prepaid twint-issuer1://
UBS twint-issuer2://
Valiant twint-issuer20://
ZKB twint-issuer3://
ZugerKB twint-issuer9://