[WhatsApp connector] deprecation of the on-premises API

[Fabilin]

TOCK currently provides two different connectors for the WhatsApp platform:

• tock-bot-connector-whatsapp, the legacy connector which is built for the WhatsApp on-premises API
• tock-bot-connector-whatsapp-cloud, a new connector in active development which is built for the WhatsApp Cloud API

However, Meta has now deprecated its on-premises API. The final compatible version of the WhatsApp client came out in January, and will expire on October 23, 2025.

Due to the retirement of the on-premises API, the legacy whatsapp connector will soon become unusable. This issue is here to discuss ways to handle this obsolescence.

Proposed actions

Short term, I would suggest deprecating all methods in the legacy WhatsApp connector very soon, if possible for version 25.3.0. This deprecation should be accompanied by a notice of the API retirement, as well as a suggestion to switch to the whatsapp-cloud connector.

Longer term, considering WhatsApp will end up supporting only the cloud API, I believe we should merge tock-bot-connector-whatsapp-cloud into tock-bot-connector-whatsapp. This merge could happen in 4 phases:

1. Methods in the whatsapp connector start delegating to their equivalents in the whatsapp-cloud connector. The two connector modules become equivalent in functionality. At this stage, tock-bot-connector-whatsapp has a dependency on tock-bot-connector-whatsapp-cloud.
2. The whatsapp cloud connector methods get deprecated, and their implementation moves over to the regular whatsapp connector. The dependency swaps around, tock-bot-connector-whatsapp-cloud depends on tock-bot-connector-whatsapp.
3. A database migration job is added to convert all "WhatsApp Cloud" application configurations to "WhatsApp" configurations
4. We retire tock-bot-connector-whatsapp-cloud, leaving only an updated tock-bot-connector-whatsapp module with the same functionality.