Can I automatically manage opt-outs for Conversation API?

Sam_Williams — Mon, 17 Nov 2025 16:05:23 GMT

Ensuring that you keep track of which customers opt-in and opt-out of different messaging campaigns is essential.

The consent management functionality of Conversation API allows you to manage the registration of opt-out messages sent by your end-users. It does so by checking the text content of inbound messages, matching that content with a set of pre-defined opt-out phrases, and, upon identifying a match, adding the corresponding contact to one of the specific opt-out categories described below:

Category	Description
`OPT_OUT_ALL`	This is the standard opt-out, and it blocks sending for all message types when consent management is used in Primary mode.
`OPT_OUT_MARKETING`	This opt-out type blocks only marketing messages when consent management is used in Primary mode. Marketing messages are defined as messages that have the `message_content_type` field set to `CONTENT_MARKETING`.
`OPT_OUT_NOTIFICATION`	This opt-out type blocks only notification messages when consent management is used in Primary mode. Notification messages are defined as messages that have the `message_content_type` field set to `CONTENT_NOTIFICATION`.

Note: Populating the message_content_type field is optional when sending messages. However, to classify messages accurately, it's considered a best practice to populate the message_content_type field. This allows the system to identify whether a message is marketing or notification-related.

If no content type is passed on the messages, the consent management functionality will assign the message to the OPT_OUT_ALL list.

Once enabled, the consent management functionality will start processing mobile originated messages. For all mobile originated messages, the consent management functionality will check for the presence of keywords that identify the message is an opt-in or opt-out message, and associate the message with a list category.

Note the following:

The system checks for an exact match. So, for example, if the keyword stop is set as the opt-out keyword, a message containing the text stop will trigger the consent management functionality. However, a message containing the text stop now please will not trigger the functionality.
The consent management matching process is case insensitive, so text like Stop, STOP, stoP, etc. would all trigger the functionality in this example case.
If no keywords are provided, a default keyword list is provided. For more information about how to customize keywords or auto-replies, see our article on keyword and auto-reply customization.

After a contact has been added to an opt-out list category, Conversation API will process messages sent to that contact based on the corresponding message_content_type value and the mode of your consent management functionality:

In Primary mode, messages directed to an opted-out contact will be blocked and an opt-out callback is delivered to your system via webhook trigger.
In Secondary mode, no blocking by Sinch is performed. The presence of an opt-in or opt-out keyword triggers the functionality when it is the sole element within an inbound, mobile originated message. The notification will then be sent via the Opt-out, Opt-in webhook triggers. Customers are required to take actions in their triggering application to prevent it from sending future messages to recipients that asked for opt-out.

To activate this functionality, see our article How do I activate consent management?.

For information on Conversation API's consents endpoint, see our API reference documentation.

Learn more about Sinch Conversation API.

article Can I automatically manage opt-outs for Conversation API? in Conversation API

Can I automatically manage opt-outs for Conversation API?