LLM Reference
GCP Vertex AI

Using Claude Fable 5 on GCP Vertex AI

Implementation guide · Claude Fable · Anthropic

Serverless

GCP Vertex AI exposes Claude Fable 5 through model ID claude-fable-5. Use the setup steps, sourced pricing, capabilities, and official provider links below to validate this route before deployment.

Last refreshed 2026-07-26. 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 claude-fable-5 — see the documentation for request format.
  3. 3
    You'll be billed $10.00/1M input, $50.00/1M output tokens. See full pricing.

Code Examples

Install
pip install google-cloud-aiplatform
API key
GOOGLE_CLOUD_PROJECT
Model ID
claude-fable-5

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("claude-fable-5")
response = model.generate_content("Hello")
print(response.text)

Pricing on GCP Vertex AI

TypePrice (per 1M)
Input tokens$10.00
Output tokens$50.00

Capabilities

VisionMultimodalReasoningJSON / Tool useStructured OutputsPrompt CachingBatch API

About Claude Fable 5

Anthropic's most capable widely released model, built for demanding reasoning and long-horizon agentic work. Claude Fable 5 is the generally available Mythos-class Claude model, supports vision, tool use, structured outputs, prompt caching, Batch API processing, adaptive thinking that is always on, a 1M-token context window, and up to 128k output tokens. It launched on the Claude API, AWS Bedrock, Vertex AI, and Microsoft Foundry on June 9, 2026 with first-party pricing at $10 per 1M input tokens and $50 per 1M output tokens.

Model Specs

Released2026-06-09
Context1m
ArchitectureDecoder Only

Provider

GCP Vertex AI
GCP Vertex AI

Google Cloud Platform (GCP)

Mountain View, California, United States