Companion to saas_template_playbook.md . That file covers everything every SaaS needs. This file covers what changes — and what's new — when AI is core to the product.

Practical-first. Code snippets, decision tables, real defaults, no buzzwords. If a section doesn't help you ship next week, it doesn't belong here.

📋 Table of Contents

⚡ The Shift in 60 Seconds

🎯 Pick One: AI-Native vs AI-Augmented

🚪 2.5 Two Starting Points: Greenfield vs Retrofit

🏗️ Reference Architecture

🤖 Agents as First-Class Actors

🔌 The LLM Gateway (Provider Abstraction)

📝 Prompts as Code

🛠️ Tools, Function Calling & MCP

🧠 Memory & RAG (the practical version)

📐 Structured Outputs

💧 Streaming UX

💵 Cost Control, Budgets & Model Routing

🧾 Outcome-Based & Metered Pricing — the implementation

✅ Evals — how to actually test agents

🔭 Observability for Agents

⚡ Caching (Prompt + Semantic)

🛡️ Safety, Abuse & PII

🙋 Human-in-the-Loop & Autonomy Levels

⏳ Long-Running Agent Jobs

🏢 AI-Specific Multi-Tenancy…