What problem does it solve? Integrating multiple large language models normally requires managing separate API keys, SDKs, and billing accounts for each provider. This Skill unifies access to 100+ models through a single CLI, with automatic model selection and cost optimization. ## Core Features & Use Cases - Multi-Model Access: Call Claude Opus 4.5, Claude Sonnet 4.5, Claude Haiku 4.5, Gemini 3 Pro, Kimi K2, GLM-4.6, and Intellect 3 through one OpenRouter-based interface. - Automatic Model Selection: The openrouter/any-model app picks the most cost-effective model for a given prompt. - System Prompt Support: Pass custom system prompts via JSON input files for controlled assistant behavior. - Use Case: A developer building a coding assistant can prototype with Claude Haiku for cheap iterations, then switch to Claude Opus for complex reasoning tasks by changing only the app ID. ## Quick Start Ask the assistant to run a prompt through Claude Sonnet using the belt CLI, for example: use the llm-models skill to ask Claude Sonnet to explain quantum computing.