Claude Opus 4.5 Extended Thinking
This skill guides optimal use of Claude Opus 4.5's extended thinking capabilities - the model's ability to reason deeply before responding, leading to more thoughtful, accurate, and nuanced outputs.
Understanding Extended Thinking
What It Is
Extended thinking allows Opus 4.5 to:
- Deliberate longer before producing output
- Consider multiple perspectives and approaches
- Self-critique and refine reasoning
- Handle complex multi-step problems
- Produce more thoughtful, less reactive responses
When It Activates
Extended thinking engages automatically when:
- Problems require multi-step reasoning
- Questions have nuance or ambiguity
- Tasks require weighing tradeoffs
- Complex analysis or synthesis is needed
- Creative work benefits from deliberation
Prompt Patterns for Deep Thinking
Pattern 1: Explicit Deliberation Request
Before answering, take time to:
1. Consider the problem from multiple angles
2. Identify potential pitfalls or edge cases
3. Weigh different approaches
4. Then provide your best response
Question: [Your complex question]Pattern 2: Multi-Perspective Analysis
I need a thorough analysis of [topic].
Please consider:
- The technical perspective
- The business/practical perspective
- The user/human perspective
- Potential risks and downsides
- Long-term implications
Take your time to reason through each before synthesizing.Pattern 3: Step-by-Step Reasoning
Walk me through your reasoning on this problem step by step.
Don't jump to conclusions - show your work.
Problem: [Complex problem]
For each step, explain:
- What you're considering
- Why you're making that choice
- What alternatives you rejected and whyPattern 4: Devil's Advocate
I'm planning to [action/decision].
Before you help me execute this:
1. Steelman the opposing view - what's the best argument against?
2. What am I potentially missing or underweighting?
3. What would make this fail?
4. Only then, if it still seems right, help me proceed.Pattern 5: Synthesis Request
I have [number] different sources/perspectives on [topic]:
[List them]
Please synthesize these into a coherent understanding that:
- Identifies where they agree
- Explains where they conflict and why
- Weighs the evidence/arguments
- Provides your reasoned conclusionTask Types That Benefit Most
1. Strategic Planning
Prompt pattern:
"Help me think through [strategic decision].
Consider: current state, desired outcome, constraints,
multiple paths, risks of each, second-order effects.
Don't rush to a recommendation - reason through thoroughly first."2. Code Architecture Decisions
Prompt pattern:
"I'm deciding between [Option A] and [Option B] for [system].
Before recommending, analyze:
- Scalability implications
- Maintenance burden
- Team capability fit
- Migration complexity
- What we might regret in 2 years"3. Creative Development
Prompt pattern:
"I want to create [creative work] about [theme].
Before writing, explore:
- Different narrative approaches
- Tonal variations
- Structural options
- What makes this theme resonate
Then develop the direction that feels most promising."4. Problem Diagnosis
Prompt pattern:
"[System/situation] is exhibiting [problem].
Don't jump to the obvious cause.
Consider:
- What are all possible causes?
- What evidence supports/refutes each?
- What's the most likely root cause?
- What would I need to verify to be sure?"5. Research Synthesis
Prompt pattern:
"Help me understand [complex topic].
I need you to:
- Break down the key concepts
- Explain how they relate
- Identify what's well-established vs debated
- Note what's commonly misunderstood
- Synthesize into a coherent mental model"Anti-Patterns to Avoid
❌ Rushing to Action
Bad: "Write me a function that does X"
Better: "I need a function that does X. Before coding,
let's consider: edge cases, error handling,
interface design, testing approach."❌ Accepting First Answer
Bad: "What's the best database for my app?"
Better: "What database should I use for [specific requirements]?
Consider multiple options, tradeoffs between them,
and what factors should weight most heavily."❌ Binary Thinking
Bad: "Should I do A or B?"
Better: "I'm choosing between A and B, but I'm open to
alternatives I haven't considered. What's the
best path forward given [context]?"❌ Ignoring Uncertainty
Bad: "Tell me the answer to [complex question]"
Better: "Help me understand [complex question].
Be explicit about what's certain vs uncertain,
and what evidence supports different views."Extended Thinking Triggers
Use these phrases to encourage deeper deliberation:
Analytical Triggers:
- "Think through this carefully..."
- "Consider all angles before responding..."
- "What are the non-obvious implications?"
- "What am I likely missing?"
- "Reason through step by step..."
Critical Triggers:
- "What could go wrong with this approach?"
- "Steelman the opposing view..."
- "What's the strongest argument against?"
- "What assumptions am I making?"
- "Where might this reasoning break down?"
Synthesis Triggers:
- "How do these pieces fit together?"
- "What's the underlying pattern?"
- "Synthesize into a coherent view..."
- "What's the essence of this?"
- "How would you explain this to an expert?"
Output Quality Indicators
Signs extended thinking is working well:
- Response acknowledges complexity and tradeoffs
- Multiple perspectives are genuinely considered
- Reasoning is visible, not just conclusions
- Uncertainty is explicitly addressed
- Edge cases and risks are surfaced proactively
- Recommendations are nuanced, not absolute
Signs it might need more prompting:
- Quick, surface-level response
- Only one perspective considered
- Confident without showing reasoning
- Missing obvious complexities
- Generic advice without context fit
Combining with Other Patterns
Extended Thinking + Agentic Execution
"First, think through the best approach to [task].
Consider alternatives and tradeoffs.
Once you have a clear plan, execute it autonomously,
but note any decision points where you chose between options."Extended Thinking + Iterative Refinement
"Draft an initial approach to [problem].
Then critique your own draft - what could be better?
Revise based on your critique.
Show me both the final version and key improvements you made."Extended Thinking + User Collaboration
"Analyze [situation] and identify the key decision points.
For each decision, explain the tradeoffs.
Before proceeding, I'll tell you my priorities,
then you can recommend the path that fits best."When NOT to Use Extended Thinking
Some tasks benefit from quick, direct responses:
- Simple factual questions
- Straightforward code snippets
- Clear instructions with no ambiguity
- Tasks where speed matters more than depth
- Follow-up execution after thinking is done
For these, don't add complexity. Just ask directly.
Model-Specific Notes (Opus 4.5)
Opus 4.5 specifically excels at:
- Sustained reasoning chains - Can maintain coherence over long analytical sequences
- Self-correction - Will catch and correct its own errors when given space
- Nuance handling - Better at "it depends" answers with clear conditions
- Multi-factor synthesis - Can hold many variables in consideration simultaneously
- Creative-analytical blend - Can reason rigorously about creative work
Integration with FrankX System
Use extended thinking for:
- Starlight Council decisions - Strategic synthesis across domains
- Architecture planning - System design for Arcanea, FrankX projects
- Content strategy - Weighing positioning, audience, platform fit
- Creative development - Book outlines, course structures, music direction
- Technical decisions - Framework choices, MCP design, agent orchestration
*Extended thinking is about quality of cognition, not length of output. The best responses come from genuine deliberation - use these patterns to unlock that capability.*