Anthropic
Claude Sonnet 5.5
claude-sonnet-5.5
Total Context
1M
Max Output
128K
Released
N/A
Input$2 / M tokens
Output$10 / M tokens
Claude 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.
Context Window
1M tokens
Maximum Output
128K tokens
Release Date
Jun 9, 2026
Modalities
Claude Fable 5 Pricing
| Input Price | Output Price | Cache Read |
|---|---|---|
| $10/M | $50/M | $1/M |
Claude Fable 5 API Capabilities
Reasoning
Supported
Tool calling
Supported
Temperature parameter
Not supported
Attachments
Supported
Knowledge Base
2026-01-31
Endpoint Protocols
Completions APIMessages API
Claude Fable 5 Model Highlights
Claude Fable 5 combines long-horizon autonomy, software engineering, visual understanding and complex knowledge work for demanding development tasks.
Long-Horizon Autonomy
Maintains focus across extended, complex tasks and can use its own notes to improve later decisions.
Large-Scale Engineering
Handles difficult production coding work and codebase-wide changes with fewer intervention points.
Visual Analytical Understanding
Interprets detailed figures, charts and screenshots while connecting visual evidence to technical reasoning.
Claude Fable 5 Use Cases
Claude Fable 5 is suited to large codebase changes, extended analytical research and demanding vision-based reconstruction tasks.
Codebase-Wide Migration
Analyze dependencies across a large repository, implement coordinated changes and validate the resulting migration.
Extended Analytical Research
Investigate complex evidence over many steps, retain intermediate findings and produce a reasoned synthesis.
Screenshot-to-Application Reconstruction
Read interface screenshots, infer structure and behavior, and generate a working implementation that matches the visual reference.
How to Use Claude Fable 5 via the TokenHub API
import OpenAI from "openai"
const client = new OpenAI({
apiKey: process.env.TOKENHUB_API_KEY,
baseURL: "https://us-api.tokenhub.com/v1",
})
const result = await client.chat.completions.create({})
console.log(result.choices[0]?.message?.content)Claude Fable 5 Benchmarks
Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback)
| Index score | ||
|---|---|---|
| Artificial Analysis Intelligence Index | Artificial Analysis broad capability aggregate | 59.9 |
| Artificial Analysis Coding Index | Artificial Analysis software task aggregate | 62 |
| 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
Claude Fable 5 Comparisons
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.
Ready to use Claude Fable 5?
Use one API key to access Claude Fable 5 and more AI models through TokenHub.
Media and Discussions
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