Zen MCP Server

Zen MCP: Many Workflows. One Context.

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AI orchestration for Claude Code - A Model Context Protocol server that gives your CLI of choice (e.g. Claude Code) access to multiple AI models for enhanced code analysis, problem-solving, and collaborative development. Zen works with Claude Code, Gemini CLI, Codex CLI as well as others.

True AI collaboration with conversation continuity - Claude stays in control but gets perspectives from the best AI for each subtask. Context carries forward seamlessly across tools and models, enabling complex workflows like: code reviews with multiple models → automated planning → implementation → pre-commit validation.

You're in control. Claude orchestrates the AI team, but you decide the workflow. Craft powerful prompts that bring in Gemini Pro, GPT 5, Flash, or local offline models exactly when needed.

1. Multi-Model Orchestration - Claude coordinates with Gemini Pro, O3, GPT-5, and 50+ other models to get the best analysis for each task
2. Context Revival Magic - Even after Claude's context resets, continue conversations seamlessly by having other models "remind" Claude of the discussion
3. Guided Workflows - Enforces systematic investigation phases that prevent rushed analysis and ensure thorough code examination
4. Extended Context Windows - Break Claude's limits by delegating to Gemini (1M tokens) or O3 (200K tokens) for massive codebases
5. True Conversation Continuity - Full context flows across tools and models - Gemini remembers what O3 said 10 steps ago
6. Model-Specific Strengths - Extended thinking with Gemini Pro, blazing speed with Flash, strong reasoning with O3, privacy with local Ollama
7. Professional Code Reviews - Multi-pass analysis with severity levels, actionable feedback, and consensus from multiple AI experts
8. Smart Debugging Assistant - Systematic root cause analysis with hypothesis tracking and confidence levels
9. Automatic Model Selection - Claude intelligently picks the right model for each subtask (or you can specify)
10. Vision Capabilities - Analyze screenshots, diagrams, and visual content with vision-enabled models
11. Local Model Support - Run Llama, Mistral, or other models locally for complete privacy and zero API costs
12. Bypass MCP Token Limits - Automatically works around MCP's 25K limit for large prompts and responses

The Killer Feature: When Claude's context resets, just ask to "continue with O3" - the other model's response magically revives Claude's understanding without re-ingesting documents!

Example: Multi-Model Code Review Workflow

1. Perform a codereview using gemini pro and o3 and use planner to generate a detailed plan, implement the fixes and do a final precommit check by continuing from the previous codereview
2. This triggers a codereview workflow where Claude walks the code, looking for all kinds of issues
3. After multiple passes, collects relevant code and makes note of issues along the way
4. Maintains a confidence level between exploring, low, medium, high and certain to track how confidently it's been able to find and identify issues
5. Generates a detailed list of critical -> low issues
6. Shares the relevant files, findings, etc with Gemini Pro to perform a deep dive for a second codereview
7. Comes back with a response and next does the same with o3, adding to the prompt if a new discovery comes to light
8. When done, Claude takes in all the feedback and combines a single list of all critical -> low issues, including good patterns in your code. The final list includes new findings or revisions in case Claude misunderstood or missed something crucial and one of the other models pointed this out
9. It then uses the planner workflow to break the work down into simpler steps if a major refactor is required
10. Claude then performs the actual work of fixing highlighted issues
11. When done, Claude returns to Gemini Pro for a precommit review

All within a single conversation thread! Gemini Pro in step 11 knows what was recommended by O3 in step 7! Taking that context and review into consideration to aid with its final pre-commit review.

Think of it as Claude Code for Claude Code. This MCP isn't magic. It's just super-glue.

Remember: Claude stays in full control — but YOU call the shots. Zen is designed to have Claude engage other models only when needed — and to follow through with meaningful back-and-forth. You're the one who crafts the powerful prompt that makes Claude bring in Gemini, Flash, O3 — or fly solo. You're the guide. The prompter. The puppeteer.

You are the AI - Actually Intelligent.

Recommended AI Stack

For best results, use Claude Code with:

• Opus 4.1 - All agentic work and orchestration
• Gemini 2.5 Pro - Deep thinking, code reviews, debugging, pre-commit analysis

Quick Start (5 minutes)

Prerequisites: Python 3.10+, Git, uv installed

1. Get API Keys (choose one or more):

• OpenRouter - Access multiple models with one API
• Gemini - Google's latest models
• OpenAI - O3, GPT-5 series
• X.AI - Grok models
• DIAL - Vendor-agnostic model access
• Ollama - Local models (free)

2. Install (choose one):

Option A: Clone and Automatic Setup (recommended)

Option B: Instant Setup with uvx

3. Start Using!

👉 Complete Setup Guide with detailed installation, configuration for Gemini / Codex, and troubleshooting

Core Tools

Note: Each tool comes with its own multi-step workflow, parameters, and descriptions that consume valuable context window space even when not in use. To optimize performance, some tools are disabled by default. See Tool Configuration below to enable them.

Collaboration & Planning (Enabled by default)

• chat - Brainstorm ideas, get second opinions, validate approaches
• thinkdeep - Extended reasoning, edge case analysis, alternative perspectives
• planner - Break down complex projects into structured, actionable plans
• consensus - Get expert opinions from multiple AI models with stance steering

Code Analysis & Quality

• debug - Systematic investigation and root cause analysis
• precommit - Validate changes before committing, prevent regressions
• codereview - Professional reviews with severity levels and actionable feedback
• analyze (disabled by default - enable) - Understand architecture, patterns, dependencies across entire codebases

Development Tools (Disabled by default - enable)

• refactor - Intelligent code refactoring with decomposition focus
• testgen - Comprehensive test generation with edge cases
• secaudit - Security audits with OWASP Top 10 analysis
• docgen - Generate documentation with complexity analysis

Utilities

• challenge - Prevent "You're absolutely right!" responses with critical analysis
• tracer (disabled by default - enable) - Static analysis prompts for call-flow mapping

Default Configuration

To optimize context window usage, only essential tools are enabled by default:

Enabled by default:

• chat, thinkdeep, planner, consensus - Core collaboration tools
• codereview, precommit, debug - Essential code quality tools
• challenge - Critical thinking utility

Disabled by default:

• analyze, refactor, testgen, secaudit, docgen, tracer

Enabling Additional Tools

To enable additional tools, remove them from the DISABLED_TOOLS list:

Option 1: Edit your .env file

Option 2: Configure in MCP settings

Option 3: Enable all tools

Note:

• Essential tools (version, listmodels) cannot be disabled
• After changing tool configuration, restart your Claude session for changes to take effect
• Each tool adds to context window usage, so only enable what you need

Key Features

AI Orchestration

• Auto model selection - Claude picks the right AI for each task
• Multi-model workflows - Chain different models in single conversations
• Conversation continuity - Context preserved across tools and models
• Context revival - Continue conversations even after context resets

Model Support

• Multiple providers - Gemini, OpenAI, X.AI, OpenRouter, DIAL, Ollama
• Latest models - GPT-5, Gemini 2.5 Pro, O3, Grok-4, local Llama
• Thinking modes - Control reasoning depth vs cost
• Vision support - Analyze images, diagrams, screenshots

Developer Experience

• Guided workflows - Systematic investigation prevents rushed analysis
• Smart file handling - Auto-expand directories, manage token limits
• Web search integration - Access current documentation and best practices
• Large prompt support - Bypass MCP's 25K token limit

Example Workflows

Multi-model Code Review:

→ Claude reviews code systematically → Consults Gemini Pro → Gets O3's perspective → Creates unified action plan

Collaborative Debugging:

→ Deep investigation → Expert analysis → Solution implementation → Pre-commit validation

Architecture Planning:

→ Structured planning → Multiple expert opinions → Consensus building → Implementation roadmap

👉 Advanced Usage Guide for complex workflows, model configuration, and power-user features

Quick Links

📖 Documentation

• Getting Started - Complete setup guide
• Tools Reference - All tools with examples
• Advanced Usage - Power user features
• Configuration - Environment variables, restrictions

🔧 Setup & Support

• WSL Setup - Windows users
• Troubleshooting - Common issues
• Contributing - Code standards, PR process

License

Apache 2.0 License - see LICENSE file for details.

Acknowledgments

Built with the power of Multi-Model AI collaboration 🤝

• Actual Intelligence by real Humans
• MCP (Model Context Protocol) by Anthropic
• Claude Code - Your AI coding orchestrator
• Gemini 2.5 Pro & Flash - Extended thinking & fast analysis
• OpenAI O3 & GPT-5 - Strong reasoning & latest capabilities

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