Sequential Thinking Skill

Installation

Optional standalone executor: The skill can run .claude/tools/optimization/sequential-thinking/executor.py. Requirements:

Python 3.10+: python.org or winget install Python.Python.3.12 (Windows), brew install python@3.12 (macOS).
MCP Python package: pip install mcp
If the executor is not present or MCP is not installed, the skill still provides in-context guidance and exits successfully.

Full functionality: The Python script .claude/tools/optimization/sequential-thinking/executor.py must exist for standalone executor runs. Run node .claude/tools/cli/doctor.mjs to verify; doctor warns if the executor is missing.

Cheat Sheet & Best Practices

Frameworks: Polya: (1) Understand the problem (2) Devise a plan (3) Carry out the plan (4) Look back. IDEAL: Identify → Define context → Explore strategies → Act on best → Look back and learn.

Process: Be systematic: preview outcomes, sustain effort, examine from multiple angles, pace and self-monitor. Use diagrams, tables, patterns; break into subgoals; work backwards when useful.

Hacks: Number thoughts (thoughtNumber, totalThoughts); allow revision and branching. Start with an initial step count and refine. Use the MCP sequential-thinking tool for multi-step analysis and hypothesis verification when the full scope is unclear.

Certifications & Training

No cert. Problem-solving frameworks: Polya (Understand → Plan → Execute → Look back), IDEAL (Identify → Define → Explore → Act → Look back). Skill data: Systematic steps; preview outcomes; sustain effort; revise and branch; use diagrams/tables/patterns.

Hooks & Workflows

Suggested hooks: Optional: pre-plan or pre-complex-task hook to suggest sequential-thinking for multi-step tasks. Use with planner (primary) for planning and master-orchestrator when decomposing work.

Workflows: Use with planner (primary). Flow: complex task → load sequential-thinking → emit thoughts (MCP or executor) → revise → act. See core/router-decision for when router assigns planner.

Overview

This skill provides structured problem-solving through a flexible thinking process that can adapt and evolve. Each thought can build on, question, or revise previous insights.

Context Savings: ~97% reduction

MCP Mode: ~15,000 tokens always loaded
Skill Mode: ~500 tokens metadata + on-demand loading

When to Use

Breaking down complex problems into steps
Planning and design with room for revision
Analysis that might need course correction
Problems where the full scope isn't clear initially
Multi-step solutions requiring maintained context
Filtering irrelevant information
Hypothesis generation and verification

Quick Reference

Use the MCP sequential thinking tool directly:

// Via MCP tool
mcp__sequential -
  thinking__sequentialthinking({
    thought: 'First, let me analyze the problem...',
    thoughtNumber: 1,
    totalThoughts: 5,
    nextThoughtNeeded: true,
  });

Tool: sequentialthinking

A detailed tool for dynamic and reflective problem-solving through thoughts.

Parameters

Parameter	Type	Description
`thought`	string	Your current thinking step
`thoughtNumber`	integer	Current thought number (1, 2, 3...)
`totalThoughts`	integer	Estimated total thoughts needed
`nextThoughtNeeded`	boolean	Whether another thought step is needed
`isRevision`	boolean	If this thought revises previous thinking
`revisesThought`	integer	Which thought number is being reconsidered
`branchFromThought`	integer	Branching point thought number
`branchId`	string	Identifier for current branch
`needsMoreThoughts`	boolean	If more thoughts needed at the "end"

Key Features

Adjust totalThoughts up or down as you progress
Question or revise previous thoughts
Add more thoughts even after reaching what seemed like the end
Express uncertainty and explore alternatives
Branch or backtrack (non-linear thinking)
Generate and verify solution hypotheses

Process

Start with initial estimate of needed thoughts
Feel free to question/revise previous thoughts
Add more thoughts if needed, even at the "end"
Mark thoughts that revise or branch
Generate solution hypothesis when appropriate
Verify hypothesis based on Chain of Thought
Repeat until satisfied
Set nextThoughtNeeded: false only when truly done

Tool Execution

The sequential thinking tool is available via MCP. Use it directly in your responses:

// Execute a thinking step
mcp__sequential -
  thinking__sequentialthinking({
    thought: 'Your analysis here...',
    thoughtNumber: 1,
    totalThoughts: 5,
    nextThoughtNeeded: true,
  });

Configuration

MCP server configuration stored in config.json:

Command: npx -y @modelcontextprotocol/server-sequential-thinking

Original MCP server: @modelcontextprotocol/server-sequential-thinking
MCP Converter Skill: .claude/skills/mcp-converter/

Iron Laws

NEVER set nextThoughtNeeded: false before the solution hypothesis has been verified
ALWAYS adjust totalThoughts dynamically as problem complexity becomes clear
NEVER commit to the first approach without exploring at least one alternative via branching
ALWAYS mark corrections explicitly with isRevision: true and revisesThought: N
NEVER stop at the estimated thought count if the hypothesis remains unverified

Anti-Patterns

Anti-Pattern	Why It Fails	Correct Approach
Fixed thought count	Thinking stops at an arbitrary estimate regardless of solution confidence	Set `needsMoreThoughts: true` and increase `totalThoughts` when complexity grows
No branching	Commits to the first approach without considering alternatives	Use `branchFromThought` to explore multiple solution paths before choosing
Skipping revisions	Incorrect assumptions propagate uncorrected through downstream thoughts	Mark all corrections with `isRevision: true` and `revisesThought: N`
Premature termination	Unverified hypothesis leads to incorrect or incomplete solutions	Verify the hypothesis explicitly before setting `nextThoughtNeeded: false`
No uncertainty markers	Overconfident conclusions mislead execution agents	Mark tentative thoughts explicitly; distinguish confident vs uncertain reasoning

Memory Protocol (MANDATORY)

Before starting: Read .claude/context/memory/learnings.md

After completing:

New pattern -> .claude/context/memory/learnings.md
Issue found -> .claude/context/memory/issues.md
Decision made -> .claude/context/memory/decisions.md

ASSUME INTERRUPTION: If it's not in memory, it didn't happen.

sequential-thinking