Sequential Thinking MCP Server

An MCP server implementation that provides a tool for reflective, assumption-aware reasoning through a structured thinking process that makes metacognition explicit.

Features

• Break down complex problems into manageable steps
• Revise and refine thoughts as understanding deepens
• Branch into alternative paths of reasoning
• Adjust the total number of thoughts dynamically
• Generate and verify solution hypotheses
• Identify assumptions that need verification
• Pause thinking to gather evidence from other tools
• Resume reasoning with new information

Workflow

The Sequential Thinking tool works in an iterative cycle with other evidence-gathering tools:

graph TD
    A["Sequential Thinking Tool<br/>Begin Reflective Analysis"] --> B["Generate Thoughts<br/>Identify Assumptions"]
    B --> C{"Assumptions Need<br/>Verification?"}
    C -->|Yes| D["Pause Thinking<br/>nextThoughtNeeded=false<br/>Output Assumptions"]
    C -->|No| E["Continue Thinking<br/>nextThoughtNeeded=true"]
    D --> F["Other Tools<br/>Gather Evidence<br/>(web search, file reading, etc.)"]
    F --> G["Resume Thinking<br/>With New Evidence"]
    G --> B
    E --> H{"All Assumptions<br/>Verified?"}
    H -->|No| B
    H -->|Yes| I["Final Conclusion<br/>nextThoughtNeeded=false"]

This workflow emphasizes rigorous reasoning by:

1. Explicitly identifying assumptions
2. Pausing to gather supporting evidence
3. Verifying assumptions before reaching conclusions
4. Allowing flexible iteration between thinking and evidence gathering

Tool

sequential_thinking

Facilitates reflective, assumption-aware reasoning by making thinking explicit, identifying underlying assumptions, and recognizing when external verification is needed.

Inputs:

• thought (string): The current thinking step
• nextThoughtNeeded (boolean): Whether to continue thinking or pause (can be false even with unverified assumptions)
• thoughtNumber (integer): Current thought number
• totalThoughts (integer): Estimated total thoughts needed
• assumptions (string, optional): Unverified assumptions that need evidence
• evidence (string, optional): Supporting evidence and verified assumptions
• isRevision (boolean, optional): Whether this revises previous thinking
• revisesThought (integer, optional): Which thought is being reconsidered
• branchFromThought (integer, optional): Branching point thought number
• branchId (string, optional): Branch identifier
• needsMoreThoughts (boolean, optional): If more thoughts are needed

Usage

The Sequential Thinking tool is designed for:

• Breaking down complex problems into steps
• Planning and design with room for revision
• Analysis that might need course correction
• Problems where the full scope might not be clear initially
• Tasks that need to maintain context over multiple steps
• Situations where irrelevant information needs to be filtered out

Configuration

Usage with Claude Desktop

Add this to your claude_desktop_config.json:

Local Development

{
  "mcpServers": {
    "sequential-thinking": {
      "command": "node",
      "args": ["/path/to/your/seq-think/dist/index.js"]
    }
  }
}

npx

{
  "mcpServers": {
    "sequential-thinking": {
      "command": "npx",
      "args": [
        "-y",
        "@ahxxm/server-sequential-thinking"
      ]
    }
  }
}

Usage with VS Code

For quick installation, click one of the installation buttons below...

For manual installation, add the following JSON block to your User Settings (JSON) file in VS Code. You can do this by pressing Ctrl + Shift + P and typing Preferences: Open Settings (JSON).

Optionally, you can add it to a file called .vscode/mcp.json in your workspace. This will allow you to share the configuration with others.

Note that the mcp key is not needed in the .vscode/mcp.json file.

For NPX installation:

{
  "mcp": {
    "servers": {
      "sequential-thinking": {
        "command": "npx",
        "args": [
          "-y",
          "@ahxxm/server-sequential-thinking"
        ]
      }
    }
  }
}

Building

To build the project locally:

npm run build

For production builds:

npm run build:prod

For CI/CD environments:

npm run install:ci
npm run build:prod

License

This MCP server is licensed under the MIT License. This means you are free to use, modify, and distribute the software, subject to the terms and conditions of the MIT License. For more details, please see the LICENSE file in the project repository.