POST /v1/messagesClaude Fable 5
claude-fable-5Claude Fable 5 is presented as a Mythos-level Claude model for ambitious, long-running projects. Source pages emphasize autonomous knowledge work, software engineering, vision, memory, and the ability to work for extended periods with sub-agents. Its description should feel more like a project-level collaborator than a short-turn assistant.
Total Context
1Mtokens
Max Output
128Ktokens
Released
Jun 9, 2026
Modalities
Claude Fable 5 Price
| Input Price | Output Price | Cache Read |
|---|---|---|
| $10/M | $50/M | $1/M |
Claude Fable 5 API
Claude Fable 5 Benchmark
Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback)
59.9
/100
Artificial Analysis Intelligence Index
Artificial Analysis broad capability aggregate
Index score
62
/100
Artificial Analysis Coding Index
Artificial Analysis software task aggregate
Index score
Knowledge & Reasoning
GPQA
Advanced science problem solving
92.6%
HLE
Broad expert-level exam set
53.3%
Coding & Engineering
SciCode
Scientific coding challenges
60.2%
Terminal-Bench Hard
Hard terminal task execution
62.9%
Instruction Following & Agent Tasks
IFBench
Prompt constraint adherence
63.5%
AA-LCR
Long-context reasoning
70%
τ²-Bench
Agent workflow tasks
98.5%
Metrics sourced from Artificial Analysis
Frequently asked questions about Claude Fable 5
Understand what Claude Fable 5 is, its best uses, distinguishing strengths, practical tradeoffs, and safe TokenHub integration guidance.
What is Claude Fable 5, and where does it fit in Anthropic’s model lineup?+
Claude Fable 5 is Anthropic’s highest-capability Claude tier for demanding reasoning and autonomous work. Its public availability has changed, so confirm current access and data-handling conditions before deployment.
Which workloads are the best fit for Claude Fable 5?+
Best-fit scenarios include long-horizon autonomous agents, complex multi-step reasoning, and professional document and decision analysis. Test representative inputs and define measurable acceptance criteria before production.
Why might a team select Claude Fable 5 over a smaller or older model?+
Key strengths include adaptive allocation of reasoning effort, strong autonomy on extended tasks, and effective use of tools and function calls. This combination is especially useful for complex multi-step reasoning.
What should be validated before relying on Claude Fable 5?+
Consider another model when stable, broadly available production access is mandatory, the workload is highly cost-sensitive, or the workflow cannot include human review for important decisions. Verify important factual, legal, financial, medical, or operational outputs with qualified human review.
What is the practical TokenHub setup guidance for Claude Fable 5?+
In TokenHub, select the exact model identifier displayed for Claude Fable 5, use the endpoint documented for your account, and authenticate with your TokenHub credentials. Because provider access conditions have changed, verify current TokenHub availability and any data-retention requirements before sending sensitive data.
Media and Discussions
Selected public videos and posts related to this model.
X (Twitter)
Reddit
YouTube