Anthropic ● Coming soon

Claude Fable 5.1

claude-fable-5-1

Anthropic's most capable widely released model: the successor to Fable 5, with a 1M-token context

Claude Fable 5.1 is Anthropic's most capable widely released model and the successor to Claude Fable 5, built for the hardest reasoning problems and long-running agentic work. Its list price is the same as Fable 5 ($10 input / $50 output per million tokens), while cache reads drop from $1 to $0.25. It has a 1M-token context window and up to 128K output tokens per request; thinking is always on, its depth is set with five effort levels (low to max), and it can return a readable summary of its reasoning. NezhaGate is integrating it now: leave your email and we will tell you the day it goes live.

Highlights

Anthropic's most capable widely released model, succeeding Fable 5
Same list price as Fable 5: $10 input / $50 output per million tokens; cache reads cut to $0.25 (from $1)
1M-token context window and up to 128K output tokens per request
Thinking is always on, with five effort levels (low / medium / high / xhigh / max) and readable reasoning summaries
Built for the hardest reasoning and long-running agentic tasks

Use cases

Hard reasoning, math and research analysis

Coding and agent tasks that run autonomously for a long time

Understanding and reworking large codebases as a whole

In-depth analysis of long reports, papers and document sets

Long-form writing such as fiction and scripts

FAQ

When will Claude Fable 5.1 be available on NezhaGate?

We are integrating and testing it now. The moment it is callable this page switches to live and shows the price. Leave your email and we will write that day.

How will I call it?

Either way works: the OpenAI-compatible API (set base_url to https://nezhagate.com/v1 and model to claude-fable-5-1), or the native Anthropic Messages API (point ANTHROPIC_BASE_URL in Claude Code or any Anthropic SDK at https://nezhagate.com/anthropic).

Is there a Fable model I can use today?

Yes. Claude Fable 5 (claude-fable-5) and Claude Opus 5 (claude-opus-5) are live on NezhaGate and callable right now.