claude-fable-5.1
Google LLC (Vertex AI)/🇺🇸 US/chat
Claude Fable 5.1 is Anthropic's most capable model, improving on Claude Fable 5 across agentic coding, long running agentic workflows, and knowledge work such as large code refactors, front end and visual code generation, and finance and analysis tasks. It ships a 1M token context window by default with 128K max output, is more token efficient and concise than Fable 5, and supports per message effort control. It is a Mythos class model with robust safeguards.MoreLess
Which id to call
vertex/claude-fable-5.1This exact deployment on Google LLC (Vertex AI), with no routing and no failover. Send it as the model field.
Input /1M
$10.00
$0.25 cached
Output /1M
$50.00
5.0x input
Context
1M
128K output
Added
Sep 2026
chat
Capabilities 7/8
Provider rates
What claude-fable-5.1 costs
Provider prices per 1M tokens, updated September 2, 2026.moreless
These are the upstream provider rates. Pay as you go adds 5%, or 0% if you bring your own keys, and there is no per-request fee. Prompt caching and routing change what you pay against these rates, not the rates themselves.
Input /1M
$10.00
Output /1M
$50.00
Cache write /1M
$12.50
Cache read /1M
$0.25
What a workload costs
- 100K input + 10K output
- $1.50
- 1M input + 100K output
- $15.00
- 10M input + 1M output
- $150.00
At the rates above, before caching. A cache read costs $0.25 per 1M, so repeated context lands under these figures.
OpenAI compatible
Call it in three lines
Change the base url, use your Requesty key, set the model to vertex/claude-fable-5.1. Existing OpenAI SDK code needs no other edit.
123456789101112131415from openai import OpenAI client = OpenAI( api_key="YOUR_REQUESTY_API_KEY", base_url="https://router.requesty.ai/v1", ) response = client.chat.completions.create( model="vertex/claude-fable-5.1", messages=[ {"role": "user", "content": "Explain quantum computing in one paragraph."}, ], ) print(response.choices[0].message.content)
Reference
Specs and data terms
What the catalog reports for this deployment, and what the provider does with the traffic.
Released 2026-09-01
Benchmark scores
Benchmarks measure the model, not this endpoint, so they are the same wherever these weights are served.
Artificial Analysis Coding Index: a composite of coding evaluations including LiveCodeBench, SciCode and Terminal-Bench.
Graduate-level physics, chemistry & biology questions designed to resist Googling.
Artificial Analysis Intelligence Index: a composite of multiple evaluations measuring overall model capability.
Scores from official model cards, Artificial Analysis and public leaderboards. They measure specific skills and do not capture every aspect of model quality, so test on your own workload.
Same provider
More from Google LLC (Vertex AI)
Newest first, on the same provider and the same key.
Reference
claude-fable-5.1 questions
How much does claude-fable-5.1 cost?
claude-fable-5.1 is priced at $10.00 per million input tokens and $50.00 per million output tokens when accessed via Requesty. Prompt caching is supported, which can cut effective input cost by up to 90% on repeated context. Those are the upstream provider rates: pay as you go adds 5% on top, or 0% if you bring your own provider keys.
What is the context window of claude-fable-5.1?
claude-fable-5.1 has a context window of 1M tokens, with a maximum output of 128K tokens per response. That's roughly 1,333 words of input you can fit in a single prompt.
How does claude-fable-5.1 perform on benchmarks?
claude-fable-5.1 scores 93.7% on GPQA Diamond, 81.6% on Coding Index, 65.7% on Intelligence Index. See the full benchmark chart above for results across MMLU Pro, GPQA Diamond, SWE-Bench Verified, HumanEval, MATH, AIME, MMMU, and LiveBench.
What can claude-fable-5.1 do?
claude-fable-5.1 supports vision input, tool calling, extended reasoning, prompt caching, web search, structured outputs (JSON schema), computer use. You can call it through any OpenAI-compatible client by pointing base_url to Requesty.
How do I use claude-fable-5.1 with the OpenAI SDK?
Install the OpenAI SDK, set base_url to "https://router.requesty.ai/v1", set your API key to your Requesty key, and set the model to "vertex/claude-fable-5.1". The Quickstart above shows Python, JavaScript and cURL snippets.
Can I run claude-fable-5.1 through Requesty?
Yes. claude-fable-5.1 runs through Requesty's OpenAI-compatible API, served from Google LLC (Vertex AI). You do not host the model yourself: point base_url at Requesty, set the model to "vertex/claude-fable-5.1", and requests are routed to the upstream provider with automatic failover. The same key gives you 600+ other models too.
Call claude-fable-5.1 through one endpoint
One key for this endpoint and 600+ other models. No markup on provider prices, automatic failover, caching built in.