Sequential Thinking

---
name: sequential-thinking
description: Use when complex problems require systematic step-by-step reasoning with ability to revise thoughts, branch into alternative approaches, or dynamically adjust scope. Ideal for multi-stage analysis, design planning, problem decomposition, or tasks with initially unclear scope.
license: MIT
---

# Sequential Thinking

Enables structured problem-solving through iterative reasoning with revision and branching capabilities.

## Core Capabilities

- **Iterative reasoning**: Break complex problems into sequential thought steps
- **Dynamic scope**: Adjust total thought count as understanding evolves
- **Revision tracking**: Reconsider and modify previous conclusions
- **Branch exploration**: Explore alternative reasoning paths from any point
- **Maintained context**: Keep track of reasoning chain throughout analysis

## When to Use

Use `mcp__reasoning__sequentialthinking` when:
- Problem requires multiple interconnected reasoning steps
- Initial scope or approach is uncertain
- Need to filter through complexity to find core issues
- May need to backtrack or revise earlier conclusions
- Want to explore alternative solution paths

**Don't use for**: Simple queries, direct facts, or single-step tasks.

## Basic Usage

The MCP tool `mcp__reasoning__sequentialthinking` accepts these parameters:

### Required Parameters

- `thought` (string): Current reasoning step
- `nextThoughtNeeded` (boolean): Whether more reasoning is needed
- `thoughtNumber` (integer): Current step number (starts at 1)
- `totalThoughts` (integer): Estimated total steps needed

### Optional Parameters

- `isRevision` (boolean): Indicates this revises previous thinking
- `revisesThought` (integer): Which thought number is being reconsidered
- `branchFromThought` (integer): Thought number to branch from
- `branchId` (string): Identifier for this reasoning branch

## Workflow Pattern

```
1. Start with initial thought (thoughtNumber: 1)
2. For each step:
   - Express current reasoning in `thought`
   - Estimate remaining work via `totalThoughts` (adjust dynamically)
   - Set `nextThoughtNeeded: true` to continue
3. When reaching conclusion, set `nextThoughtNeeded: false`
```

## Simple Example

```typescript
// First thought
{
  thought: "Problem involves optimizing database queries. Need to identify bottlenecks first.",
  thoughtNumber: 1,
  totalThoughts: 5,
  nextThoughtNeeded: true
}

// Second thought
{
  thought: "Analyzing query patterns reveals N+1 problem in user fetches.",
  thoughtNumber: 2,
  totalThoughts: 6, // Adjusted scope
  nextThoughtNeeded: true
}

// ... continue until done
```

## Advanced Features

For revision patterns, branching strategies, and complex workflows, see:
- [Advanced Usage](.codex/skills/sequential-thinking/references/advanced.md) - Revision and branching patterns
- [Examples](.codex/skills/sequential-thinking/references/examples.md) - Real-world use cases

## Tips

- Start with rough estimate for `totalThoughts`, refine as you progress
- Use revision when assumptions prove incorrect
- Branch when multiple approaches seem viable
- Express uncertainty explicitly in thoughts
- Adjust scope freely - accuracy matters less than progress visibility