Sequential Thinking & UltraThink

Structured reasoning system for complex problem analysis and decision-making.

Activation Triggers

Use Sequential Thinking MCP when:

• Breaking down complex problems into steps

• Planning and design with room for revision

• Architecture decisions affect 3+ files

• Technology selection between multiple options

• Performance vs maintainability trade-offs

• Breaking changes under consideration

• Multiple approaches exist to solve the same problem

• Repetitive errors occur

Tool Parameters

Required Parameters:

• thought (string): Current thinking step content

• nextThoughtNeeded (boolean): Whether another step is needed

• thoughtNumber (integer): Current thought number (starts from 1)

• totalThoughts (integer): Estimated total thoughts needed

Optional Parameters:

• isRevision (boolean): Whether this revises previous thinking

• revisesThought (integer): Which thought is being reconsidered

• branchFromThought (integer): Branching point for alternatives

• branchId (string): Branch identifier

• needsMoreThoughts (boolean): If more thoughts needed beyond estimate

Usage Pattern

Step 1 - Initial Analysis:

thought: "Analyzing the problem: [describe problem]" nextThoughtNeeded: true thoughtNumber: 1 totalThoughts: 5

Step 2 - Decomposition:

thought: "Breaking down: [sub-problems]" nextThoughtNeeded: true thoughtNumber: 2 totalThoughts: 5

Step 3 - Revision (if needed):

thought: "Revising thought 2: [correction]" isRevision: true revisesThought: 2 thoughtNumber: 3 totalThoughts: 5 nextThoughtNeeded: true

Final Step - Conclusion:

thought: "Conclusion: [final answer]" thoughtNumber: 5 totalThoughts: 5 nextThoughtNeeded: false

UltraThink Mode

Enhanced analysis mode activated by --deepthink flag.

Activation:

"Implement authentication system --deepthink" "Refactor the API layer --deepthink"

Process:

• Request Analysis: Identify core task, detect keywords, recognize complexity

• Sequential Thinking: Begin structured reasoning

• Execution Planning: Map subtasks to agents, identify parallel opportunities

• Execution: Launch agents, integrate results

UltraThink Parameters:

Initial Analysis:

thought: "Analyzing user request: [content]" nextThoughtNeeded: true thoughtNumber: 1 totalThoughts: [estimate]

Subtask Decomposition:

thought: "Breaking down: 1) [task1] 2) [task2] 3) [task3]" nextThoughtNeeded: true thoughtNumber: 2

Agent Mapping:

thought: "Mapping: [task1] → expert-backend, [task2] → expert-frontend" nextThoughtNeeded: true thoughtNumber: 3

Execution Strategy:

thought: "Strategy: [tasks1,2] parallel, [task3] depends on [task1]" nextThoughtNeeded: true thoughtNumber: 4

Final Plan:

thought: "Plan: Launch [agents] in parallel, then [agent]" nextThoughtNeeded: false

When to Use

UltraThink is ideal for:

• Complex multi-domain tasks (backend + frontend + testing)

• Architecture decisions affecting multiple files

• Performance optimization requiring analysis

• Security review needs

• Refactoring with behavior preservation

Benefits:

• Structured decomposition of complex problems

• Explicit agent-task mapping with justification

• Identification of parallel execution opportunities

• Context maintenance throughout reasoning

• Revision capability when approaches need adjustment

Guidelines

• Start with reasonable totalThoughts estimate

• Use isRevision when correcting previous thoughts

• Maintain thoughtNumber sequence

• Set nextThoughtNeeded to false only when complete

• Use branching for exploring alternatives