Programming reference · verified 17 Jul 2026
Write prompts that make hard coding work feel tractable.
Build a prompt, find a proven pattern, or diagnose a response that went off track.
Scope: Claude Fable 5 / Mythos 5, plus current cross-model prompting practices
Fast paths
Choose what you’re doing
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Pocket library
Prompt patterns
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Favorites
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Guided workflow
Prompt builder
Answer four short questions. Your inputs stay in this browser and are inserted into a reusable prompt.
Decision guide
Fix a result
Choose the closest symptom. You’ll get a focused diagnosis, a prompt patch, and a fallback path.
Primary sources
Verified against Anthropic documentation
This fieldbook summarizes and restructures official guidance; it is not affiliated with Anthropic. Links require a network connection.
01
Prompting Claude Fable 5Model-specific behavior, long runs, effort, memory, safety
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02Prompting best practicesClarity, examples, XML, long context, tools, agent workflows
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03Models overviewAvailability, model IDs, capabilities, compatibility
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04EffortSupported levels and capability/latency/token trade-offs
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05Refusals and fallbackFable 5 refusal stop reason and fallback handling
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