/tags/anthropic/ Recent content in Anthropic on AI Prompt Toolkit Hugo en-us Thu, 18 Jun 2026 00:00:00 +0000 /prompts/claude-fable-5-master-prompts/ Thu, 18 Jun 2026 00:00:00 +0000 /prompts/claude-fable-5-master-prompts/ <h2 id="claude-fable-5--mythos-5--full-prompt-guide">Claude Fable 5 &amp; Mythos 5 — Full Prompt Guide</h2> <p>Released <strong>June 9, 2026</strong>, Claude Fable 5 and Mythos 5 represent Anthropic&rsquo;s first public <strong>Mythos-class</strong> models. They achieve state-of-the-art results across software engineering, knowledge work, vision, and scientific research.</p> <h3 id="key-capabilities">Key Capabilities</h3> <table> <thead> <tr> <th>Capability</th> <th>Fable 5</th> <th>Mythos 5</th> </tr> </thead> <tbody> <tr> <td><strong>Pricing</strong></td> <td>~$10/M input</td> <td>~$10/M input, $50/M output</td> </tr> <tr> <td><strong>Context Window</strong></td> <td>1M+ tokens</td> <td>1M+ tokens</td> </tr> <tr> <td><strong>Extended Thinking</strong></td> <td>✅</td> <td>✅ (deeper)</td> </tr> <tr> <td><strong>Vision</strong></td> <td>Native</td> <td>Native</td> </tr> <tr> <td><strong>Best For</strong></td> <td>Coding, iteration</td> <td>Research, architecture</td> </tr> <tr> <td><strong>vs Claude Opus 4.8</strong></td> <td>Beats on all benchmarks</td> <td>Significantly ahead</td> </tr> </tbody> </table> <h3 id="prompting-strategy">Prompting Strategy</h3> <ol> <li><strong>Structure is everything.</strong> Fable 5 rewards explicit output formats — specify sections, evidence requirements, and confidence levels.</li> <li><strong>Extended thinking is a superpower.</strong> Enable it for any task with more than 3 reasoning steps.</li> <li><strong>Vision is native, not bolted on.</strong> Include images directly for UI review, diagram analysis, and spatial reasoning.</li> <li><strong>Long context is transformative.</strong> At 100K+ tokens, both models maintain focus and cross-reference accuracy that degrades in other models.</li> </ol> <h3 id="when-to-use-which-model">When to Use Which Model</h3> <ul> <li><strong>Fable 5</strong>: Daily coding, code review, writing, data analysis, quick research</li> <li><strong>Mythos 5</strong>: Architecture design, multi-paper research synthesis, complex debugging, security audits, scientific hypothesis generation</li> </ul>