Claude Fable 5.1

Anthropic's most capable model for demanding reasoning and long-horizon agentic work, extending Claude Fable 5 with stronger agentic coding, multistep research, and document work.

claude-fable-5-1
STABLEGet StartedView uptime
1,000,000 context
Released September 1, 2026
Starting at $10.00/M input tokens
Starting at $50.00/M output tokens
Streaming
Vision
Tools
Reasoning
Structured JSON
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All Providers for Claude Fable 5.1

LLM Gateway routes requests to the best providers that are able to handle your prompt size and parameters.

Context: 1M
Input
$10
/M tokens
Cache Read
$0.25
/M tokens
Output
$50
/M tokens
Cache Write 5m
$12.5
/M tokens
Cache Write 1h
$20
/M tokens
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Frequently asked questions

What is Claude Fable 5.1?

Anthropic's most capable model for demanding reasoning and long-horizon agentic work, extending Claude Fable 5 with stronger agentic coding, multistep research, and document work. You can access it through LLM Gateway's OpenAI-compatible API with automatic provider routing, fallback, and cost analytics.

How much does Claude Fable 5.1 cost?

Pricing for Claude Fable 5.1 on LLM Gateway starts at $10.00 per million input tokens and $50.00 per million output tokens, depending on the provider. The pricing table above always reflects the current per-provider rates.

What is the context length of Claude Fable 5.1?

Claude Fable 5.1 supports a context window of up to 1,000,000 tokens on its largest provider deployment.

Which providers serve Claude Fable 5.1?

Claude Fable 5.1 is served by Anthropic through LLM Gateway. Requests are automatically routed to the best available provider, with fallback when a provider has issues.

Does Claude Fable 5.1 support tool calling and structured outputs?

Yes. Claude Fable 5.1 supports both tool (function) calling and strict JSON output schema (upstream-enforced) through LLM Gateway.

When was Claude Fable 5.1 released?

Claude Fable 5.1 was released on September 1, 2026.