Facebook is three channels in one prompt
A Facebook agent has to juggle public comments, Lead Ad forms and private Messenger threads, three surfaces with three tones. A comment reply is short and public; a Messenger thread is a sales conversation; a Lead Ad follow-up is a warm re-open. One flat prompt cannot hold all three. Architecture is what keeps them straight.
The four layers
MyChatBot agents stack in layers. System sets brand identity and guardrails. Role narrows the job, and you can run separate sales, support and lead-triage agents on one Page. Memory is the Knowledge Base: Business Domain docs and a Product Feed, so answers come from facts. Tools is where it acts, CRM writes, calendar checks, order creation. Change a price in the Feed and every surface updates; you never touch the prompt.
Reading intent across surfaces
The agent classifies intent before it speaks: is this a price question, a complaint, a collaboration pitch, a ready buyer? On a public comment it stays brief and pivots to DM; in Messenger it goes deep with Agentic Search; on a Lead Ad it references the exact form answer. Same brain, surface-aware behavior.
What silently burns credits
The quiet budget killers: re-loading the whole catalogue per message, re-asking for info the lead already gave, and verbose system text repeated on every turn. Fix it with narrow Agentic Search retrieval, CRM memory so context persists, and tight system layers. Architecture is not just quality, it is cost control.
Designing the handoff
Hand-off Control is part of the architecture, not a bolt-on. Define the stop-word, the value threshold and the emotional cues that send a thread to a human, with silent hand-off and Flight Control in Telegram. Then ship it: the Configuration Wizard battle-tests and versions every change, so you tune tone and triggers without ever starting over.