model-routerlisted

# Purpose Pick the cheapest capability tier that still yields excellent results, and suggest which OS skills to run. # When to Use / When NOT to Use **Use when:** starting a non-trivial task; cost/latency matters; engineering-os wants a tier hint. **Do not use when:** user already pinned a model; task is already mid-flight with a working setup. # Preconditions Task description available. Optional: risk, context size estimate, deadline. # Inputs / Outputs **Inputs:** task, risk, rough context size, iteration expectation. **Outputs:** `ROUTE_DECISION` # Upstream / Downstream **Upstream:** engineering-os, user. **Downstream:** whatever skills are suggested—router does not execute them. # Core Principles 1. Optimize quality-to-cost. 2. Route by capability tier, not brand names. 3. Risk elevates tier. 4. Large context elevates long-context tier or demands context-loader first. 5. Always provide a fallback chain. 6. Prefer skill sequence over “use a bigger model for everything.” 7. Never do the task. # Process 1. **Classify** — architecture, coding, debugging, review, docs, security, etc. 2. **Complexity** — Trivial → Very High (reasoning depth, unknowns, cross-service—not just file count). 3. **Risk** — Low/Medium/High/Critical elevates tier one step when ≥ High. 4. **Context** — if huge, recommend context-loader + long-context tier; avoid stuffing. 5. **Select tier:** | Tier | Use for | |------|---------| | `fast` | tiny edits, formatting, simple Q&A | | `coding`