Anthropic · Frontier
Claude Fable Latest
Compatibility alias for Claude Fable 5.1. Anthropic retains prompts and outputs for 30 days under its Covered Models policy; Zero Data Retention is not available.
- Reasoning
- Tools
- Vision
- Structured output
- PDF input
- Input
- Text, Images
- Output
- Text
- Reasoning effort
- low · medium · high · xhigh · max
- Discovery tier
- Frontier
Pricing
USD per 1M tokens- Input
- $10.00
- Output
- $50.00
- Cache read
- $0.25
- Cache write
- $12.50
- $20.00 for a 1-hour cache
Reference prices as published by the model provider. API example
Specifications
- Context window
- 1M
- Max output
- 128K
Side by side
Compare models
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Public evaluations
Benchmarks
Independent evaluation results, with how each score ranks among the models in the Noumen catalog.
Intelligence Index
53.4
Tested at max reasoning effort
Better than 98% of 326 scored models
Indexes
Coding Index
81.6Composite of the coding evaluations
Better than 99% of 168 scored models
Agentic work
AutomationBench-AA
59.4%Workflow automation, penalized for guardrail violations
Better than 78% of 173 scored models
AutomationBench-AA tasks completed
32.1%Workflows finished end to end without a guardrail violation
Better than 90% of 173 scored models
Harvey LAB-AAv1.1
6.4%Legal tasks passed in full, with no material hallucination
Better than 89% of 29 scored models
AA-Briefcasev1.1
1,671 EloAgentic knowledge work, rated head to head
Better than 96% of 166 scored models
GDPval-AAv2.1
1,755 EloEconomically valuable occupational tasks, rated head to head
Better than 97% of 187 scored models
Document reasoning
GDP.pdf
26.2%Professional reasoning over PDF documents, all-pass rate
Better than 90% of 171 scored models
AA-LCRv1.1
85.3%Reasoning across long documents
Better than 97% of 309 scored models
MLCR-AA
15.6%Long-context reasoning over medical records
Better than 66% of 121 scored models
Reasoning and knowledge
Humanity’s Last Exam
59.1%Expert-level questions across academic fields
Better than 99% of 323 scored models
GPQA Diamond
93.7%Graduate-level science questions
Better than 94% of 291 scored models
Coding
Terminal-Benchv4.0
52.0%Practical software engineering in a terminal
Better than 95% of 171 scored models
SciCode
63.1%Scientific computing in Python
Better than 99% of 174 scored models
Legacy evaluations
AA-LCR (unversioned)
85.3%Long-context reasoning, earlier grading
Better than 97% of 309 scored models
Scores from Artificial Analysis, updated Oct 26, 2026. Claude Fable Latest was tested at max reasoning effort; compare scores measured at the same effort.Artificial Analysis
Live routing data
Performance and reliability
Recent averages across requests routed for this model. Your own speed depends on prompt length, reasoning effort and load.
- Throughput
- 79.4 tok/s
- Faster than 52% of 256 models
- Time to first token
- 5.2 s
- Quicker than 27% of 256 models
- Prompt cache hits
- 33.8%
- About $6.71 per 1M input tokens with caching
- Request success (24h)
- 99.0%
- Reliable
Cache hits are the share of input tokens recently served from a prompt cache across all requests. They are not a forecast of your own hit rate.
- Healthy (98% or more)
- Degraded (90–98%)
- Down (under 90%)
- No requests
Developers
Use it through the API
Noumen’s API is OpenAI-compatible: any Chat Completions client works with a base URL and a key.
curl https://www.noumen.xyz/api/v1/chat/completions \
-H "Authorization: Bearer $NOUMEN_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "anthropic/claude-fable-latest",
"reasoning_effort": "medium",
"messages": [{ "role": "user", "content": "Explain this stack trace." }]
}'import os
from openai import OpenAI
client = OpenAI(base_url="https://www.noumen.xyz/api/v1", api_key=os.environ["NOUMEN_API_KEY"])
reply = client.chat.completions.create(
model="anthropic/claude-fable-latest",
messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)Anthropic
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