What this model error usually means
OpenAI: GPT-5.1 Chat returning 429 / model rate limited means you should first confirm whether model ID openai/gpt-5.1-chat is visible for this OpenAI key, then separate permission, context, capability, rate limit, or route issues.
- Model: openai/gpt-5.1-chat
- Provider: OpenAI
- Status code: 429