#+TITLE: PRD: LLM Failover Cascade & Multi-Provider Support
#+AUTHOR: PSF Requirements Definer
#+STATUS: FROZEN

* 1. Purpose
Ensure 100% availability of System 1 (Neural) reasoning via an ordered list of providers and automatic fallbacks.

* 2. Functional Requirements
- **Backend Registry:** The core MUST allow Skills to register new AI providers (Gemini, OpenAI, Claude, etc.).
- **Automatic Failover:** The `ask-neuro` function MUST iterate through a `*provider-cascade*` list, automatically trying the next provider if the previous one fails.
- **Interactive Re-Ordering:** The system MUST allow the user to update the cascade order in real-time from Emacs.

* 3. Success Criteria
 - DONE Daemon correctly falls back from a failing API key to a working one.
 - DONE `M-x org-agent-set-model-cascade` successfully updates the live Lisp hierarchy.
 - DONE Support for 5+ providers (Gemini, OpenAI, Anthropic, OpenRouter, Ollama).