claude-fable-5.1
Anthropic/Proprietary/2 providers
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
anthropic/claude-fable-5.1This model has no managed policy yet, so call the provider endpoint directly. Every id in the endpoints table works the same way.
From /1M input
$10.00
Anthropic PBC
Context
1M
128K output
Endpoints
3
2 regions
Regions
2
chat
Capabilities 7/8
3 endpoints / 2 regions
Providers serving claude-fable-5.1
Provider prices, per 1M tokens. Pay as you go adds 5%, or 0% on your own keys.
| Rank | Privacy | ||||||
|---|---|---|---|---|---|---|---|
| 1 | Anthropic PBC | Global | 1M | $10.00 | $50.00 | $0.25 | no-train |
| 2 |  Google LLC (Vertex AI) | Global | 1M | $10.00 | $50.00 | $0.25 | no-train |
| 3 | Google LLC (Vertex AI) | eu | 1M | $11.00 | $55.00 | $0.28 | no-train |
A column is blank where no qualifying sample exists, and every row links to that provider's endpoint page.
model=
Which id to call
One base url, https://router.requesty.ai/v1, and one key for every id here.
anthropic/claude-fable-5.1This model has no managed policy yet, so call the provider endpoint directly. Every id in the endpoints table works the same way.
OpenAI compatible
Call it in three lines
Change the base url, use your Requesty key, set the model to any id on the left. 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="anthropic/claude-fable-5.1", messages=[ {"role": "user", "content": "Explain quantum computing in one paragraph."}, ], ) print(response.choices[0].message.content)
Artificial Analysis
Benchmark scores
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 artificialanalysis.ai. They measure the model, not the provider, so they are the same on every endpoint above.
6
More from Anthropic
Reference
claude-fable-5.1 questions
Which providers serve claude-fable-5.1?
claude-fable-5.1 is available from 2 providers through Requesty: Anthropic PBC, Google LLC (Vertex AI). All endpoints share one OpenAI-compatible API and one key, and Requesty fails over between them automatically.
How much does claude-fable-5.1 cost?
Pricing starts at $10.00 per million input tokens and $50.00 per million output tokens on Anthropic PBC, the cheapest endpoint. Prices vary by provider and region; the table above shows every endpoint. Those are the upstream provider rates: pay as you go adds 5% on top, or 0% if you bring your own provider keys.
Is claude-fable-5.1 open weights?
No. claude-fable-5.1 is a proprietary model from Anthropic, served through Anthropic's own API and licensed cloud platforms.
What is the context window of claude-fable-5.1?
claude-fable-5.1 supports up to 1M tokens of context, with up to 128K output tokens per response. Some providers expose a smaller window; check the per-endpoint context column above.
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 "anthropic/claude-fable-5.1" or any endpoint id from the table above. The quickstart section shows Python, JavaScript and cURL snippets.
Route claude-fable-5.1 through one endpoint
One key for 2 providers on this model and 600+ others. No markup on provider prices, automatic failover, caching built in.