text issues with twilio

[nicolasburtey]

a lot of people have issues receiving text. we are in touch with twilio to try to resolve the issue. one of the reason could be that the phone number used to send the text is coming from the US but being sent to El Salvador

we may want to try an alternative system to see if this works better. a non exhaustive list of providers:

• http://www.otpsmsapi.com/index.html
• https://voxvalley.com/sms/
• https://smsala.com/transactional-sms

[dolcalmi]

or add "retry options" with other messenger services (like whatsapp or telegram)

[nicolasburtey]

the whatsapp fallback (or even primary) option is something I have been thinking about.

some of the benefits would be:

• most people have a whatsapp in developing countries
• there is no cost (AFAIK? maybe would be different if this is related to a business usage using an API as opposed to manual message through the app) to send a message

question:

• is there an API for it?
• we currently associate an account to a phone number. we need to build a layer of abstraction to also have email, 2fa and co (more in this page). but I think on Whatsapp account are not tight to a single phone number permanently because there is a way to migrate to another phone number (AFAIK). it would be important to understand if this could created issue where 2 accounts could have the same phone number unintentionally or if this could create some unintended attack vector.

[dolcalmi]

• is there an API for it?

we can keep using twilio https://www.twilio.com/whatsapp but there is a cost. we could also use AWS SNS or messagebird, or... we can use an automated call with the code (we can use twilio too but not sure about the cost).

• Whatsapp account are not tight to a single phone number

you can transfer the account to a new number or use it with "another" phone number if you change the SIM, but in general is a way to reduce SMS problems.

[nicolasburtey]

we can keep using twilio https://www.twilio.com/whatsapp but there is a cost. we could also use AWS SNS or messagebird, or... we can use an automated call with the code (we can use twilio too but not sure about the cost).

the cost are actually about what it is for text unfortunately: https://www.twilio.com/whatsapp/pricing/sv doesn't make a lot of sense for me on why that is the case

it's possible an integration with the local telco to be the most efficient way to go forward

[nicolasburtey]

actually there would still be some benefits to try Whatsapp. currently about 1% of the text doesn't seems to arrive. it seems to be because the phone number sending the text are from the US. I'm trying to understand why that is with the twilio support. but using Whatsapp, while not helping on the cost side, may solve this deliverability issue.

[nicolasburtey]

maybe an option that would help would be to randomize the text being sent and now include "bitcoin" in the string.

[nicolasburtey]

duplicated ticket: https://github.com/GaloyMoney/galoy/issues/284