GPT 5.1 Thinking
GPT 5.1 Thinking is the reasoning-focused member of the GPT-5.1 family, applying extended chain-of-thought computation to produce more thorough and accurate responses on complex analytical, scientific, and multi-step problems.
import { streamText } from 'ai'
const result = streamText({ model: 'openai/gpt-5.1-thinking', prompt: 'Why is the sky blue?'})Frequently Asked Questions
How does GPT 5.1 Thinking reasoning work?
It generates internal reasoning tokens that work through the problem step by step before producing a visible response, similar to the approach used in o-series reasoning models.
When should I use thinking versus instant?
Use thinking for complex analysis, math, science, and hard coding problems where accuracy is the priority. Use instant for real-time chat, streaming content, and tasks where speed is the priority.
Is GPT 5.1 Thinking slower than GPT-5.1 instant?
Yes. The extended reasoning process adds time before the first visible output. The tradeoff is deeper, more accurate reasoning on complex problems.
What context window does GPT 5.1 Thinking support?
400K tokens, supporting the lengthy inputs that complex reasoning tasks often require.
How does AI Gateway handle authentication for GPT 5.1 Thinking?
AI Gateway accepts a single API key or OIDC token for all requests. You don't embed OpenAI credentials in your application; AI Gateway routes and authenticates on your behalf.
What are typical latency characteristics?
This page shows live throughput and time-to-first-token metrics measured across real AI Gateway traffic.