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Opt-out keywords

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Proxy Public Beta is not available to new customers

Proxy Public Beta is currently closed for new customers. Please consider using Twilio Conversations and Programmable Voice directly if you are building your masking application.

Note that this does not have any impact on Twilio Flex customers.

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Public Beta for customers already using Proxy

Twilio's Proxy API is currently available as a Public Beta product. Some features are not yet implemented and others may be changed before the product is declared as Generally Available.

Public Beta products are not covered by a Twilio SLA.

How Proxy handles opt-out and opt-in keywords

By default, Twilio handles opt-out and opt-in keywords as described in Twilio support for opt-out keywords (SMS STOP filtering) document; when Twilio receives an opt-out keyword from an external sender phone number to any Twilio number, Twilio will reply with a pre-generated response and will no longer send messages from the Twilio Number to that external phone number until the sender opts back in by sending an opt-in keyword.

When using SMS with Proxy, there are special considerations and deviations from the standard handling of opt-out and opt-in keywords:

Proxy will not forward STOP, UNSUBSCRIBE, END, CANCEL, QUIT, STOPALL, ARRETT, ARRET, ARRETE (opt-out) messages from either participant. Dropped messages do not trigger callbacks.
Proxy forwards all opt-in, help and info keywords between Participants, except UNSTOP, to ensure that potentially valid messages are not lost.
For any opt-in/out message not forwarded, Proxy will send a debugger notification with Twilio code 80901 .
Proxy does not support the Advanced Opt Out feature available with Messaging Services.
Unlike with a Messaging Service, opt-out keyword replies will not apply to the entire pool of phone numbers in a Proxy Service pool.
If you would like Proxy to respect the STOP SMS Filtering flag, contact our support team to submit a request to enable the ProxyRespectSmsStopFilterFlag account flag. Once Twilio enables this, custom opt-in/out keyword handling can be accomplished by adding the desired logic to Proxy's InterceptCallbackUrl .