Give a WhatsApp AI assistant selective long-term memory

Goal: Make my WhatsApp assistant remember important facts about users.
Setup: agents used in source: n8n; tools/MCPs stated: n8n, WhatsApp.
Steps:
1. Detect important information in each message instead of storing everything.
2. Save only those details.
3. Retrieve them when the user returns.
Rules: ask me before anything irreversible (sending, posting, paying, deleting); don’t invent data, results or tools I haven’t given you; tell me what you couldn’t verify.
Based on: /u/cuebicai — https://www.reddit.com/r/n8n/comments/1ws34sk/built_an_n8n_workflow_for_a_whatsapp_ai_assistant/ (summarised from source; the source has no explicit step list)

Steps are our summary of the source (it has no explicit step list). Includes a “Based on” credit line.