MCP server Official

Sequential Thinking MCP Server

Reference MCP server with one tool for step-by-step reasoning that can revise and branch thoughts.

Author: Model Context Protocol
Works with: Any MCP client
License: MIT
Documented: Oct 2, 2026

What Sequential Thinking MCP Server is

Provides a sequential_thinking tool for dynamic, reflective problem solving. The model calls it repeatedly, tracking thought numbers, revisions and branches.

What it does

Where Sequential Thinking MCP Server runs and what it adds, from its documentation

Break complex problems into steps
Revise earlier thoughts
Branch into alternative reasoning paths
Adjust the total number of thoughts dynamically
Generate and verify solution hypotheses

When to use it

Good fit

Planning and design with room for revision
Debugging where the full scope is unclear at first

Not for

Simple one-shot questions
Production use without review: The root README says these are reference implementations meant as educational examples, not production-ready solutions.

How to install Sequential Thinking MCP Server

You need: Node.js (npx) or Docker

Make sure Node.js is available
Add the npx command to your MCP client config
Restart the host so it reconnects
Ask for step-by-step reasoning and check for repeated sequential_thinking calls

Configuration example (from the official docs)

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

Permissions and security

What it can access

No external access described; the tool only records thoughts

Security notes from the maintainers

The root README says these are reference implementations meant as educational examples, not production-ready solutions.

Review the source before granting an agent access to credentials or production systems. We document what the maintainers state; we do not audit code.

Limitations

The host decides when to call the tool; you normally do not call it by hand

Frequently asked questions

How do I know the Sequential Thinking server is working?

You should see repeated sequential_thinking calls with thought, thoughtNumber, totalThoughts and nextThoughtNeeded. source

Can Sequential Thinking MCP branch or revise?

Yes, via isRevision, revisesThought, branchFromThought and branchId. source

What is the npm package?

@modelcontextprotocol/server-sequential-thinking. source

Related guides

Sources and gaps

https://raw.githubusercontent.com/modelcontextprotocol/servers/main/src/sequentialthinking/README.md readme, checked Oct 2, 2026
https://raw.githubusercontent.com/modelcontextprotocol/servers/main/README.md readme, checked Oct 2, 2026

Not stated by the maintainers: Hosts other than generic MCP clients are not individually named as supported for Claude Code/Cursor/Windsurf/Codex in this README; last_release date not visible in the checked README.