Using Grok 4.1 Fast on GCP Vertex AI

Implementation guide · Grok 4 · xAI

Serverless

GCP Vertex AI exposes Grok 4.1 Fast through model ID grok-4.1-fast. Use the setup steps, sourced pricing, capabilities, and official provider links below to validate this route before deployment.

Last refreshed 2026-10-18. Next refresh: weekly.

Quick Start

  1. 1
    Create an account at GCP Vertex AI and generate an API key.
  2. 2
    Use the GCP Vertex AI SDK or REST API to call grok-4.1-fast — see the documentation for request format.
  3. 3
    You'll be billed $0.20/1M input, $0.50/1M output tokens. See full pricing.
API PortalDocumentationPricing

Code Examples

Install
pip install google-cloud-aiplatform
API key
GOOGLE_CLOUD_PROJECT
Model ID
grok-4.1-fast

For Google-published models use the model name directly, e.g. "gemini-2.0-flash-001". For third-party publishers (Anthropic, Meta, etc.) use the full publisher path, e.g. "publishers/anthropic/models/claude-3-5-sonnet-v2@20241022".

import os
import vertexai
from vertexai.generative_models import GenerativeModel

# Reads GOOGLE_CLOUD_PROJECT from env; authenticates via Application Default Credentials
vertexai.init(project=os.environ["GOOGLE_CLOUD_PROJECT"], location="us-central1")
model = GenerativeModel("grok-4.1-fast")
response = model.generate_content("Hello")
print(response.text)

Pricing on GCP Vertex AI

TypePrice (per 1M)
Input tokens$0.20
Output tokens$0.50

Capabilities

VisionMultimodalReasoningJSON / Tool useStructured Outputs

About Grok 4.1 Fast

Ultra-low latency Grok 4.1 Fast API family. xAI retired grok-4-1-fast-reasoning and grok-4-1-fast-non-reasoning on 2026-05-15; requests now redirect to Grok 4.3 at Grok 4.3 pricing.

Full model details →

Model Specs

Released2025-11-19
Context2M

Also available on(4)

OpenRouter$0.20/1MMicrosoft Foundry$0.20/1MVercel AI Gateway$0.20/1M
Compare all providers →

Provider

GCP Vertex AI

Google Cloud Platform (GCP)

Mountain View, California, United States