infrastructure-model-routing-litellm-proxy-returns-404-error-when-calling-the-r-f95d932f

THEN Register the model in LiteLLM's `model_prices_and_context_window.json` file with proper pricing and context window metadata. If the model is not mapped, the Responses API fails because it requires model info for routing. Alternatively, use the chat completions endpoint (`/v1/chat/completions`) which does not enforce this mapping. For custom models, add an entry like: `{ "model": "openai/gpt-oss-120b", "input_cost_per_token": 1e-7, "output_cost_per_token": 5e-7 }`.

// Add to model_prices_and_context_window.json
{
  "openai/gpt-oss-120b": {
    "input_cost_per_token": 1e-7,
    "output_cost_per_token": 5e-7,
    "max_tokens": 4096
  }
}