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GPT OSS 120B

GPT OSS 120B is OpenAI's open-source 120-billion parameter language model, offering strong general-purpose capability with the transparency and flexibility of open weights.

ReasoningTool Use
index.ts
import { streamText } from 'ai'
const result = streamText({
model: 'openai/gpt-oss-120b',
prompt: 'Why is the sky blue?'
})

Frequently Asked Questions

  • What does 'open-source' mean for GPT OSS 120B?

    The model weights are publicly available. You can inspect and audit the model while using it through managed APIs.

  • How does GPT OSS 120B compare to GPT-5?

    GPT-5 is OpenAI's closed-source general-purpose model with higher capability. GPT OSS 120B offers strong general-purpose performance with the advantage of open weights and model transparency.

  • What context window does GPT OSS 120B support?

    131.1K tokens, providing substantial capacity for document processing and extended conversations.

  • How does AI Gateway handle authentication for GPT OSS 120B?

    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.