OpenAI models

OpenAI models on Vertex AI offer fully managed and serverless models as APIs. To use an OpenAI model on Vertex AI, send a request directly to the Vertex AI API endpoint. Because OpenAI models use a managed API, there's no need to provision or manage infrastructure.

You can stream your responses to reduce the end-user latency perception. A streamed response uses server-sent events (SSE) to incrementally stream the response.

Available OpenAI models

The following models are available from OpenAI to use in Vertex AI. To access an OpenAI model, go to its Model Garden model card.

gpt-oss-120b

OpenAI gpt-oss-120b is a 120B open-weight language model released under the Apache 2.0 license. It is well-suited for reasoning and function calling use cases. The model is optimized for deployment on consumer hardware.

The 120B model achieves near-parity with OpenAI o4-mini on core reasoning benchmarks, while running on a single 80GB GPU.

Go to the gpt-oss-120b model card

gpt-oss-20b

OpenAI gpt-oss-20b is a 20B open-weight language model released under the Apache 2.0 license. It is well-suited for reasoning and function calling use cases. The model is optimized for deployment on consumer hardware.

The 20B model delivers similar results to OpenAI o3-mini on common benchmarks and can run on edge devices with 16GB of memory, making it ideal for on-device use cases, local inference, or rapid iteration without costly infrastructure.

Go to the gpt-oss-20b model card

Before you begin

To use OpenAI models with Vertex AI, you must perform the following steps. The Vertex AI API (aiplatform.googleapis.com) must be enabled to use Vertex AI. If you already have an existing project with the Vertex AI API enabled, you can use that project instead of creating a new project.

  1. Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.

  2. In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

    Go to project selector

  3. Verify that billing is enabled for your Google Cloud project.

  4. Enable the Vertex AI API.

    Enable the API

  5. In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

    Go to project selector

  6. Verify that billing is enabled for your Google Cloud project.

  7. Enable the Vertex AI API.

    Enable the API

    8.
  8. Go to one of the following Model Garden model cards, then click Enable.