The Provider Router is Agent Platform's model and tool gateway: it unifies 30+ providers, MCP tool discovery, step-local permission control, fallback chains with RRF fusion, and an OpenAI-compatible Proxy that existing SDKs can use without code changes. It is configuration-driven rather than hard-coded, with provider-health-aware routing.
Hermes supports 40+ providers, and the consumer-subscription OAuth paths are where billing surprises live: Anthropic OAuth only spends Claude Max extra-usage credits, and Claude Pro can't use it at all. Auxiliary tasks default to `provider: auto`, meaning your expensive main model does compression and vision grunt work. The fallback chain is a one-shot switch per session, not continuous retry.
Spin up a local OpenAI-compatible endpoint at localhost:20128 that automatically routes requests from Claude Code / Cursor / Cline / Codex / Copilot through a Subscription → Cheap → Free 3-tier fallback to 40+ providers. Built-in RTK compresses tool_result (saving 20–40% input tokens), Caveman mode compresses output, OAuth auto-refresh, multi-account round-robin — install with npm install -g 9router and two commands.
Filters too strict and getting zero results? CRAG automatically relaxes them and retries — far better than letting the LLM hallucinate an answer from general knowledge.