Claude Fable 5
Claude Fable 5 is a Mythos-class model from Anthropic, built for autonomous knowledge work and coding.
Model by Anthropic
Chalk Labs
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Install
Pick your client. Read the repository before you give any tool access to your data.
{
"model": "anthropic/claude-fable-5",
"baseURL": "https://openrouter.ai/api/v1"
}OpenAI-compatible API: point any OpenAI SDK at the base URL and use this model id.
Settings it needs
OPENROUTER_API_KEYrequiredsecret
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About
Use cases: code-generation, model-inference
Reviews
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Price and limits
| Variant | Input $/M tokens | Output $/M tokens | Cached input $/M |
|---|---|---|---|
| Standard | $10 | $50 | $1 |
Batch API anthropic/claude-fable-5:batch | $5 | $25 | — |
Price as of Oct 26, 2026 from OpenRouter · provider's own prices: docs.claude.com. Prices change often; check before you rely on one.
- Provider
- Anthropic
- Model id
anthropic/claude-fable-5- Context window
- 1,000,000 tokens (1M)
- Max output
- 128,000 tokens
- Input
- text, image, file
- Output
- text
- Tool calling
- Yes
- Structured outputs
- Yes
- Reasoning
- Yes
- Weights
- Closed
- Released
- Jun 9, 2026
Details
- Auth
- API key
- License
- Proprietary
- Website
- www.anthropic.com
- First seen
- Oct 24, 2026
- Last checked
- Oct 26, 2026
- Source
- OpenRouter
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Done for you
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Rahil Jain, Co-founder, Chalk Labs. Ex-Goldman Sachs engineer. You talk to the person who builds it.
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Cite this page
Claude Fable 5: price, context window, tool use. Agent Mart. https://agentmart.dev/models/anthropic-claude-fable-5 (last updated 2026-10-26)