Using GCP Vertex AI With Roo Code

Roo Code supports accessing models through Google Cloud Platform's Vertex AI, a managed machine learning platform that provides access to various foundation models, including Anthropic's Claude family.

Website: https://cloud.google.com/vertex-ai

Prerequisites

• Google Cloud Account: You need an active Google Cloud Platform (GCP) account.
• Project: You need a GCP project with the Vertex AI API enabled.
• Model Access: You must request and be granted access to the specific Claude models on Vertex AI you want to use. See the Google Cloud documentation for instructions.
• Application Default Credentials (ADC): Roo Code uses Application Default Credentials to authenticate with Vertex AI. The easiest way to set this up is to:
  1. Install the Google Cloud CLI: https://cloud.google.com/sdk/docs/install
  2. Authenticate using: gcloud auth application-default login
• Service Account Key (Alternative): Alternatively, you can authenticate using a Google Cloud Service Account key file. You'll need to generate this key in your GCP project. See the Google Cloud documentation on creating service account keys.

Supported Models

Roo Code supports the following models through Vertex AI (based on source code):

• Google Gemini Models:
  • gemini-2.5-flash-preview-05-20
  • gemini-2.0-flash-001
  • gemini-2.5-pro-exp-03-25
  • gemini-2.0-pro-exp-02-05
  • gemini-2.0-flash-lite-001
  • gemini-2.0-flash-thinking-exp-01-21
  • gemini-1.5-flash-002
  • gemini-1.5-pro-002
• Anthropic Claude Models:
  • claude-opus-4@20250514:thinking
  • claude-opus-4@20250514
  • claude-sonnet-4@20250514:thinking
  • claude-sonnet-4@20250514
  • claude-3-7-sonnet@20250219:thinking
  • claude-3-7-sonnet@20250219
  • claude-3-5-sonnet-v2@20241022
  • claude-3-5-sonnet@20240620
  • claude-3-5-haiku@20241022
  • claude-3-opus@20240229
  • claude-3-haiku@20240307

Refer to the Google Cloud documentation on Vertex AI Models for the most up-to-date list of available models and their IDs.

Configuration in Roo Code

1. Open Roo Code Settings: Click the gear icon () in the Roo Code panel.
2. Select Provider: Choose "GCP Vertex AI" from the "API Provider" dropdown.
3. Configure Authentication:
   • If using Application Default Credentials (ADC): No further action is needed here. ADC will be used automatically if configured correctly (see Prerequisites).
   • If not using ADC (Service Account Key):
     • Option A: Paste JSON Content: Paste the entire content of your Service Account JSON key file into the Google Cloud Credentials field.
     • Option B: Provide File Path: Enter the absolute path to your downloaded Service Account JSON key file in the Google Cloud Key File Path field.
4. Enter Project ID: Enter your Google Cloud Project ID.
5. Select Region: Choose the region where your Vertex AI resources are located (e.g., us-east5).
6. Select Model: Choose your desired model from the "Model" dropdown.

Tips and Notes

• Permissions: Ensure your Google Cloud account has the necessary permissions to access Vertex AI and the specific models you want to use.
• Pricing: Refer to the Vertex AI pricing page for details.