Vertex AI¶

Run models through Google Cloud's Vertex AI platform. Both claude-vertex and gemini-vertex use Application Default Credentials (ADC) — no API keys to manage.

Prerequisites¶

A Google Cloud project with the Vertex AI API enabled
Application Default Credentials configured:

gcloud auth application-default login

IAM Roles

Your account needs the Vertex AI User role (roles/aiplatform.user) on the GCP project.

Environment Variables¶

Env Var	Required	Default	Description
`GOOGLE_CLOUD_PROJECT`	Yes	--	GCP project ID
`GOOGLE_CLOUD_LOCATION`	No	`us-central1` (gemini) / `global` (claude)	GCP region

claude-vertex¶

Claude models on Vertex AI via @anthropic-ai/vertex-sdk with the createClient pattern, wrapped by @langchain/anthropic.

Default region is global

Unlike other Vertex AI models, Claude on Vertex defaults to the global region, not us-central1. Set GOOGLE_CLOUD_LOCATION explicitly if you need a specific region.

Model Naming¶

Model names match the Anthropic API format -- no special Vertex-specific naming required.

API Name	Vertex Name
`claude-opus-4-6`	`claude-opus-4-6`
`claude-sonnet-4-20250514`	`claude-sonnet-4-20250514`

Setup¶

Environment FileExport

.env

LLM_PROVIDER=claude-vertex
GOOGLE_CLOUD_PROJECT=my-gcp-project-id
# GOOGLE_CLOUD_LOCATION=global  # default for claude-vertex

export LLM_PROVIDER=claude-vertex
export GOOGLE_CLOUD_PROJECT=my-gcp-project-id

Usage¶

pnpm run generate -- --provider claude-vertex

# Override region
GOOGLE_CLOUD_LOCATION=us-east5 pnpm run generate -- --provider claude-vertex

gemini-vertex¶

Gemini models on Vertex AI via @langchain/google-vertexai (ChatVertexAI). The GCP project is passed via authOptions.projectId.

Setup¶

Environment FileExport

.env

LLM_PROVIDER=gemini-vertex
GOOGLE_CLOUD_PROJECT=my-gcp-project-id
# GOOGLE_CLOUD_LOCATION=us-central1  # default for gemini-vertex

export LLM_PROVIDER=gemini-vertex
export GOOGLE_CLOUD_PROJECT=my-gcp-project-id

Usage¶

pnpm run generate -- --provider gemini-vertex

# Override model and region
pnpm run generate -- --provider gemini-vertex --model gemini-2.5-pro \
  GOOGLE_CLOUD_LOCATION=europe-west1

Region Availability¶

Check model availability by region

Not all models are available in all regions. Consult the Vertex AI documentation for current regional availability: