Structure Complex Problem-Solving Sequences

Sequential Thinking MCP Server

An MCP server implementation that provides a tool for dynamic and reflective problem-solving through a structured thinking process.

Published on npm as @modelcontextprotocol/server-sequential-thinking.

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

Tool

sequential_thinking

Facilitates a detailed, step-by-step thinking process for problem-solving and analysis.

Inputs:

• thought (string): The current thinking step
• nextThoughtNeeded (boolean): Whether another thought step is needed
• thoughtNumber (integer): Current thought number
• totalThoughts (integer): Estimated total thoughts needed
• 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

In practice, you do not call sequential_thinking directly by hand unless your client exposes raw tool calls. Instead, connect the server to an MCP-aware host and ask the model to think through a problem step by step. The host can then decide to call the tool one or more times while it works.

What it looks like in use

Example prompts that typically benefit from this tool:

• Plan a database migration from PostgreSQL 14 to 16, list risks, and revise the plan if downtime exceeds 5 minutes.
• Debug why this deployment only fails in production and show your reasoning step by step.
• Compare three architecture options for a file sync engine and branch if one assumption turns out to be wrong.

How to tell it is working

If your host or inspector shows tool activity, you should see repeated calls to sequential_thinking with fields such as:

• thought
• thoughtNumber
• totalThoughts
• nextThoughtNeeded

When the reasoning changes course, you may also see revision or branching fields like isRevision, revisesThought, branchFromThought, or branchId.

Quick manual verification

After installing the server in your MCP host:

1. Restart or reload the host so it reconnects to the server.
2. Confirm the sequential_thinking tool appears in the host's MCP tool list or inspector.
3. Ask the host to solve a non-trivial problem in a step-by-step way.
4. Verify that the host invokes the tool multiple times instead of returning a one-shot answer.

Configuration

Usage with Claude Desktop

Add this to your claude_desktop_config.json:

npx

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

On Windows, use cmd /c to launch npx:

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

docker

{
  "mcpServers": {
    "sequentialthinking": {
      "command": "docker",
      "args": [
        "run",
        "--rm",
        "-i",
        "mcp/sequentialthinking"
      ]
    }
  }
}

To disable logging of thought information set env var: DISABLE_THOUGHT_LOGGING to true.

Usage with VS Code

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

For manual installation, you can configure the MCP server using one of these methods:

Method 1: User Configuration (Recommended)
Add the configuration to your user-level MCP configuration file. Open the Command Palette (Ctrl + Shift + P) and run MCP: Open User Configuration. This will open your user mcp.json file where you can add the server configuration.

Method 2: Workspace Configuration
Alternatively, you can add the configuration to a file called .vscode/mcp.json in your workspace. This will allow you to share the configuration with others.

For more details about MCP configuration in VS Code, see the official VS Code MCP documentation.

For NPX installation:

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

On Windows, use:

{
  "servers": {
    "sequential-thinking": {
      "command": "cmd",
      "args": [
        "/c",
        "npx",
        "-y",
        "@modelcontextprotocol/server-sequential-thinking"
      ]
    }
  }
}

For Docker installation:

{
  "servers": {
    "sequential-thinking": {
      "command": "docker",
      "args": [
        "run",
        "--rm",
        "-i",
        "mcp/sequentialthinking"
      ]
    }
  }
}

Usage with Codex CLI

Run the following:

npx

codex mcp add sequential-thinking npx -y @modelcontextprotocol/server-sequential-thinking

Building

Docker:

docker build -t mcp/sequentialthinking -f src/sequentialthinking/Dockerfile .