sequential-think

name

sequential-think

description

Multi-step reasoning engine for complex analysis and systematic problem solving. Use when: (1) Complex debugging scenarios with multiple layers, (2) Architectural analysis and system design, (3) Problems requiring hypothesis testing and validation, (4) Multi-component failure investigation, (5) Performance bottleneck identification. Triggers: "--think", "--think-hard", "--ultrathink", "analyze step by step", "break down this problem", "systematic analysis". IMPORTANT: Do NOT use for simple single-step tasks.

Sequential Think

Structured iterative thinking for complex problem-solving. Standalone CLI only (no MCP dependency).

Execution Methods

Run scripts/sequential_think_cli.py via Bash:

# Process a thought
python scripts/sequential_think_cli.py think \
  --thought "First, let me analyze the problem structure..." \
  --thought-number 1 \
  --total-thoughts 5

# Continue thinking chain
python scripts/sequential_think_cli.py think \
  --thought "Based on step 1, I hypothesize that..." \
  --thought-number 2 \
  --total-thoughts 5

# Revise a previous thought
python scripts/sequential_think_cli.py think \
  --thought "Reconsidering step 1, I realize..." \
  --thought-number 3 \
  --total-thoughts 5 \
  --is-revision \
  --revises-thought 1

# Branch into alternative path
python scripts/sequential_think_cli.py think \
  --thought "Alternative approach: what if we..." \
  --thought-number 4 \
  --total-thoughts 6 \
  --branch-from 2 \
  --branch-id "alt-approach"

# Final thought (complete chain)
python scripts/sequential_think_cli.py think \
  --thought "Conclusion: the solution is..." \
  --thought-number 5 \
  --total-thoughts 5 \
  --no-next

# View thought history
python scripts/sequential_think_cli.py history [--format json|text]

# Clear thought history
python scripts/sequential_think_cli.py clear

Core Principles

Iterative Thinking Process

• Each tool call = one "thought" in the chain
• Build upon, question, or revise previous thoughts
• Express uncertainty when it exists

Dynamic Thought Count

• Start with initial estimate of totalThoughts
• Adjust up/down as understanding evolves
• Add more thoughts even after reaching initial end

Hypothesis-Driven Approach

1. Generate hypotheses as potential solutions emerge
2. Verify hypotheses based on chain-of-thought steps
3. Repeat until satisfied with solution

Completion Criteria

• Only set nextThoughtNeeded: false when truly finished
• Must have satisfactory, verified answer
• Don't rush to conclusion

When to Use

Scenario	Use Sequential Think
Complex debugging (3+ layers)	✅ Yes
Architectural analysis	✅ Yes
Multi-component investigation	✅ Yes
Performance bottleneck analysis	✅ Yes
Root cause analysis	✅ Yes
Simple explanation	❌ No
Single-file change	❌ No
Straightforward fix	❌ No

Parameters

Parameter	Type	Required	Description
thought	string	Yes	Current thinking step content
thoughtNumber	int	Yes	Current position in sequence (1-based)
totalThoughts	int	Yes	Estimated total thoughts needed
nextThoughtNeeded	bool	No	Whether more thinking needed (default: true)
isRevision	bool	No	Whether this revises previous thinking
revisesThought	int	No	Which thought number is being reconsidered
branchFromThought	int	No	Branching point thought number
branchId	string	No	Identifier for current branch
needsMoreThoughts	bool	No	Signal that more thoughts needed beyond estimate

Output Format

{
  "thoughtNumber": 3,
  "totalThoughts": 5,
  "nextThoughtNeeded": true,
  "branches": ["alt-approach"],
  "thoughtHistoryLength": 3
}

Workflow Pattern

Phase 1: Problem Decomposition

Thought 1: Identify problem scope and constraints
Thought 2: Break into sub-problems
Thought 3: Identify dependencies between sub-problems

Phase 2: Hypothesis Generation

Thought 4: Generate initial hypothesis
Thought 5: Identify evidence needed to verify

Phase 3: Verification & Iteration

Thought 6: Test hypothesis against evidence
Thought 7: Revise if needed (isRevision=true)
Thought 8: Branch if alternative path promising

Phase 4: Conclusion

Final Thought: Synthesize findings, provide answer (nextThoughtNeeded=false)

Best Practices

1. Start with estimate, adjust as needed

   • Initial totalThoughts is just a guess
   • Increase if problem more complex than expected
   • Decrease if solution found early

2. Use revisions for course correction

   • Mark isRevision=true when reconsidering
   • Reference revisesThought for clarity

3. Branch for alternative approaches

   • Use branchFromThought to explore alternatives
   • Give meaningful branchId names

4. Filter irrelevant information

   • Each thought should advance toward solution
   • Ignore tangential details

5. Don't rush completion

   • Only nextThoughtNeeded=false when truly done
   • Verify hypothesis before concluding

Anti-Patterns

Prohibited	Correct
Use for simple tasks	Reserve for complex multi-step problems
Skip thought numbers	Always increment correctly
Conclude without verification	Verify hypothesis before final thought
Ignore previous thoughts	Build upon or explicitly revise
Fixed totalThoughts	Adjust as understanding evolves

Integration with Other Tools

With ACE-Tool

ACE-Tool → align current state → Sequential Think → analyze and plan

With Context7

Sequential Think → coordinate analysis → Context7 → provide official patterns

With Serena

Serena → symbol-level exploration → Sequential Think → systematic analysis