How requests reach a provider The Osprey agent speaks the Anthropic Messages API. Providers that already speak it are reached directly; providers that offer only an OpenAI-compatible endpoint are reached through a local translation proxy that OSPREY starts at launch. MCP tool servers are a separate client stack — they use LiteLLM and do not travel the agent's path. Osprey agent Anthropic Messages API MCP tool servers a separate client stack native — nothing in between Anthropic-native endpoint anthropic · cborg · als-apg local translation proxy Anthropic ↔ OpenAI random port, started at launch OpenAI-compatible endpoint stanford · argo · asksage · amsc-i2 ollama · vllm · ds4 LiteLLM not the agent's path any provider whatever LiteLLM can call keep the trailing /v1 on an OpenAI-compatible base_url — the proxy needs it; the agent's own requests have it stripped api_protocol: anthropic routes a custom Anthropic-speaking gateway down the direct lane instead