Tetrad

Quadruple consensus MCP server for code validation using Codex, Gemini, and Qwen

Quick Install

Automated & IDE Setup

Copy the AI prompt to install this server into Claude Code, Cursor, or another agent — or use 1-click editor setup below.

Add to Cursor Add to VS Code

Not yet automatically verified

We haven't yet run this listing's install command through our automated sandbox check. This isn't a red flag — we're steadily working through the catalog.

Manual Client & Custom JSON ConfigExpand JSON ▾

Client Config & Setup

Choose your client or environment

Target File:~/Library/Application Support/Claude/claude_desktop_config.json

claude_desktop_config.json

{
  "mcpServers": {
    "tetrad": {
      "command": "npx",
      "args": [
        "-y",
        "@samoradc/tetrad"
      ]
    }
  }
}

💡 Paste the JSON block into your client's configuration file under mcpServers, then restart the application.

Capabilities & Tool Schemas (6)Self-reported

Inspect callable tools, capabilities, and parameters exposed to AI agents by Tetrad.

tetrad_review_plan

Review implementation plans before coding

tetrad_review_code

Review code before saving

tetrad_review_tests

Review tests before finalizing

tetrad_confirm

Confirm agreement with received feedback

tetrad_final_check

Final verification before commit

tetrad_status

Check health of evaluators

Documentation Overview

Tetrad

Quadruple Consensus MCP Server for Claude Code

Tetrad is a high-performance MCP (Model Context Protocol) server written in Rust that orchestrates three AI-powered CLI code evaluation tools (Codex, Gemini CLI, Qwen) to validate all code produced by Claude Code.

The system implements a quadruple consensus protocol where no code or plan is accepted without approval from four intelligences: the three external evaluators + Claude Code itself.

Features

Quadruple Consensus: 4 AI models must agree to approve code
ReasoningBank: Continuous learning system with RETRIEVE→JUDGE→DISTILL→CONSOLIDATE cycle
High Performance: Written in Rust with parallel execution via Tokio
MCP Server: JSON-RPC 2.0 server over stdio for Claude Code integration
Full CLI: Intuitive commands (init, serve, status, doctor, config, etc.)
LRU Cache: Result caching with configurable TTL
Hook System: Pre/post evaluation callbacks for customization
Extensible: Plugin system for custom executors
Cross-session: SQLite persistence for patterns and history

Quick Start

1. Install Tetrad

bash

# Via npm (recommended - works seamlessly with Claude Code)
npm install -g @samoradc/tetrad

# Or via cargo (requires additional setup)
cargo install tetrad
sudo cp ~/.cargo/bin/tetrad /usr/local/bin/

1.1 Initialize in Your Project (Optional)

Terminal

npx @samoradc/tetrad init

This will:

Create tetrad.toml configuration file
Create .tetrad/ directory for the database
Add .tetrad/ to your .gitignore

2. Install and Configure External CLI Tools

Tetrad requires at least one of the following AI CLI tools. Good news: you don't need separate API keys if you have existing subscriptions!

Codex CLI (OpenAI)

Terminal

npm install -g @openai/codex

Authentication options:

Method	Requirements	API Key Needed?
ChatGPT Login	ChatGPT Plus, Pro, Business, Edu, or Enterprise subscription	No
API Key	OpenAI API account with credits	Yes

server.ts

# Option 1: Login with your ChatGPT subscription (recommended)
codex login
# Opens browser for OAuth - follow the prompts

# Option 2: Use API key
export OPENAI_API_KEY="your-openai-key"

Note: For headless/remote servers, use codex login --device-auth and follow the device code flow.

📖 Codex CLI Authentication Docs

Gemini CLI (Google)

Terminal

npm install -g @google/gemini-cli

Authentication options:

Method	Requirements	API Key Needed?	Free Tier
Google Login	Personal Google account	No	60 req/min, 1,000 req/day
API Key	Google AI Studio account	Yes	Same limits

server.ts

# Option 1: Login with Google account (recommended)
gemini auth login
# Opens browser for OAuth - follow the prompts

# Option 2: Use API key from Google AI Studio
export GEMINI_API_KEY="your-gemini-key"

Free Tier: With a personal Google account, you get access to Gemini 2.5 Pro with 1M token context window at no cost!

📖 Gemini CLI Authentication Docs

Qwen CLI (Alibaba)

Terminal

npm install -g qwen-code

Authentication options:

Method	Requirements	API Key Needed?	Free Tier
DashScope API	Alibaba Cloud account	Yes	2,000 req/day
Coding Plan	Qwen Coding subscription	Yes (different format)	Included

server.ts

# Get your API key from DashScope console
export DASHSCOPE_API_KEY="your-dashscope-key"

# For international users (outside China)
export OPENAI_BASE_URL="https://dashscope-intl.aliyuncs.com/compatible-mode/v1"

Regional Endpoints:

Singapore: dashscope-intl.aliyuncs.com

Virginia: dashscope-us.aliyuncs.com

Beijing: dashscope.aliyuncs.com

📖 Qwen API Docs

3. Verify Installation

bash

# Check Tetrad version
tetrad version

# Check CLI availability
tetrad status

# Diagnose any issues
tetrad doctor

4. Add to Claude Code CLI

bash

# Add Tetrad as MCP server (all projects)
claude mcp add --scope user tetrad -- npx @samoradc/tetrad serve

# Verify it's configured
claude mcp list

Alternative installation methods

bash

# Current project only
claude mcp add tetrad -- npx @samoradc/tetrad serve

# If installed via cargo
claude mcp add --scope user tetrad -- tetrad serve

Note: Tetrad is published on the MCP Registry for discoverability and documentation.

5. Alternative: Manual Configuration

Create or edit .mcp.json in your project root:

config.json

{
  "mcpServers": {
    "tetrad": {
      "type": "stdio",
      "command": "npx",
      "args": ["@samoradc/tetrad", "serve"],
      "env": {
        "OPENAI_API_KEY": "${OPENAI_API_KEY}",
        "GOOGLE_API_KEY": "${GOOGLE_API_KEY}",
        "DASHSCOPE_API_KEY": "${DASHSCOPE_API_KEY}"
      }
    }
  }
}

Or for global user configuration in ~/.claude.json (mcpServers section):

config.json

{
  "mcpServers": {
    "tetrad": {
      "type": "stdio",
      "command": "npx",
      "args": ["@samoradc/tetrad", "serve"]
    }
  }
}

How It Works

When you ask Claude Code to write code, Tetrad automatically validates it:

Code

You: "Create a function in Rust that calculates the average of a vector"

Claude Code:
1. Writes the code
2. Calls tetrad_review_code automatically
3. Tetrad sends to Codex, Gemini and Qwen for evaluation
4. Returns consolidated consensus from all 3 evaluators

Tetrad Response:
┌─────────────────────────────────────────────┐
│ DECISION: PASS ✓                            │
│ Score: 92/100                               │
│ Consensus: Yes (3/3 approved)               │
│                                             │
│ Votes:                                      │
│   • Codex:  Pass (95)                       │
│   • Gemini: Pass (90)                       │
│   • Qwen:   Pass (92)                       │
│                                             │
│ Suggestions:                                │
│   - Consider handling empty vector case     │
└─────────────────────────────────────────────┘

Claude Code: Saves the approved code

When Issues Are Found:

Code

Tetrad Response:
┌─────────────────────────────────────────────┐
│ DECISION: BLOCK ✗                           │
│ Score: 26/100                               │
│ Consensus: Yes (3/3 rejected)               │
│                                             │
│ Votes:                                      │
│   • Codex:  Fail (30) - division by zero    │
│   • Gemini: Fail (25) - no error handling   │
│   • Qwen:   Fail (25) - unsafe operation    │
│                                             │
│ Issues:                                     │
│   - Division by zero not handled            │
│   - Missing input validation                │
│   - No Result/Option return type            │
└─────────────────────────────────────────────┘

Claude Code: Fixes the code and resubmits

CLI Commands

server.ts

tetrad - Quadruple Consensus CLI for Claude Code

COMMANDS:
    init              Initialize configuration in current directory
    serve             Start the MCP server (used by Claude Code)
    status            Show CLI status (codex, gemini, qwen)
    config            Configure options interactively
    doctor            Diagnose configuration issues
    version           Show version
    evaluate          Evaluate code manually (without MCP)
    history           Show evaluation history from ReasoningBank
    export            Export patterns from ReasoningBank
    import            Import patterns into ReasoningBank

OPTIONS:
    -c, --config <FILE>    Configuration file (default: tetrad.toml)
    -v, --verbose          Verbose mode
    -q, --quiet            Quiet mode
    -h, --help             Show help

MCP Tools

When running as MCP server, Tetrad exposes 6 tools:

Tool	Description
`tetrad_review_plan`	Review implementation plans before coding
`tetrad_review_code`	Review code before saving
`tetrad_review_tests`	Review tests before finalizing
`tetrad_confirm`	Confirm agreement with received feedback
`tetrad_final_check`	Final verification before commit
`tetrad_status`	Check health of evaluators

Workflow Example

Code

1. Claude Code generates plan → tetrad_review_plan → Feedback
2. Claude Code implements   → tetrad_review_code → Feedback
3. Claude Code adjusts      → tetrad_confirm     → Confirmation
4. Claude Code finalizes    → tetrad_final_check → Certificate

Architecture

Read the full README →View source on GitHub →

Related MCP Servers

View all in Developer Tools View all alternatives

Adoption & maintenance

Factual signals from GitHub, npm, and our automated checks — not a rating.

GitHub stars

Stargazers on the source repository.

npm downloads

228

Package downloads in the last 30 days.

Last commit

7mo ago

Most recent push to the default branch.

Tools exposed

Callable tools this server registers over MCP.

Reviews

No reviews yet — be the first to share how this listing worked for you.

Frequently Asked Questions about Tetrad

Add the following block to your claude_desktop_config.json under mcpServers: "mcpServers": { "tetrad": { "command": "npx", "args": ["-y","@samoradc/tetrad"] } }

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Technical Specs & Signals

CategoryDeveloper Tools

5/9 checks healthy over the last 45d

49Quality signal: Fair · 49/100How this signal is calculated ▾

Server availabilityNot measured

Not scored for repo-hosted servers — we can't reach the running server, only its GitHub page. Hosted MCP endpoints are health-checked live.

Verified ownership10/20

Documentation & tools24/30

Adoption & activity3/15

Community engagement0/10

A guidance signal from public completeness & health data — not a user rating. New listings start lower and rise as they add docs, get verified, and grow adoption. Signals we can't observe for a listing are skipped, not counted against it.

Supply-chain signal

No high-severity advisories surfaced by our automated scan.

Critical 0High 0Medium 0Low 0

Scanned 1d ago via OSV.dev · @samoradc/tetrad (npm)

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More in 💻 Developer Tools →Best MCP servers for Developers →Alternatives to Tetrad →Install in Claude Desktop Install in Cursor Install in VS Code Setup guides for all 13 MCP clients

Tetrad

Quadruple consensus MCP server for code validation using Codex, Gemini, and Qwen

Quick Install

Automated & IDE Setup

Copy the AI prompt to install this server into Claude Code, Cursor, or another agent — or use 1-click editor setup below.

Add to Cursor Add to VS Code

Not yet automatically verified

We haven't yet run this listing's install command through our automated sandbox check. This isn't a red flag — we're steadily working through the catalog.

Manual Client & Custom JSON ConfigExpand JSON ▾

Client Config & Setup

Choose your client or environment

Target File:~/Library/Application Support/Claude/claude_desktop_config.json

claude_desktop_config.json

{
  "mcpServers": {
    "tetrad": {
      "command": "npx",
      "args": [
        "-y",
        "@samoradc/tetrad"
      ]
    }
  }
}

💡 Paste the JSON block into your client's configuration file under mcpServers, then restart the application.

Capabilities & Tool Schemas (6)Self-reported

Inspect callable tools, capabilities, and parameters exposed to AI agents by Tetrad.

tetrad_review_plan

Review implementation plans before coding

tetrad_review_code

Review code before saving

tetrad_review_tests

Review tests before finalizing

tetrad_confirm

Confirm agreement with received feedback

tetrad_final_check

Final verification before commit

tetrad_status

Check health of evaluators

Documentation Overview

Tetrad

Quadruple Consensus MCP Server for Claude Code

The system implements a quadruple consensus protocol where no code or plan is accepted without approval from four intelligences: the three external evaluators + Claude Code itself.

Features

Quadruple Consensus: 4 AI models must agree to approve code
ReasoningBank: Continuous learning system with RETRIEVE→JUDGE→DISTILL→CONSOLIDATE cycle
High Performance: Written in Rust with parallel execution via Tokio
MCP Server: JSON-RPC 2.0 server over stdio for Claude Code integration
Full CLI: Intuitive commands (init, serve, status, doctor, config, etc.)
LRU Cache: Result caching with configurable TTL
Hook System: Pre/post evaluation callbacks for customization
Extensible: Plugin system for custom executors
Cross-session: SQLite persistence for patterns and history

Quick Start

1. Install Tetrad

bash

# Via npm (recommended - works seamlessly with Claude Code)
npm install -g @samoradc/tetrad

# Or via cargo (requires additional setup)
cargo install tetrad
sudo cp ~/.cargo/bin/tetrad /usr/local/bin/

1.1 Initialize in Your Project (Optional)

Terminal

npx @samoradc/tetrad init

This will:

Create tetrad.toml configuration file
Create .tetrad/ directory for the database
Add .tetrad/ to your .gitignore

2. Install and Configure External CLI Tools

Tetrad requires at least one of the following AI CLI tools. Good news: you don't need separate API keys if you have existing subscriptions!

Codex CLI (OpenAI)

Terminal

npm install -g @openai/codex

Authentication options:

Method	Requirements	API Key Needed?
ChatGPT Login	ChatGPT Plus, Pro, Business, Edu, or Enterprise subscription	No
API Key	OpenAI API account with credits	Yes

server.ts

# Option 1: Login with your ChatGPT subscription (recommended)
codex login
# Opens browser for OAuth - follow the prompts

# Option 2: Use API key
export OPENAI_API_KEY="your-openai-key"

Note: For headless/remote servers, use codex login --device-auth and follow the device code flow.

📖 Codex CLI Authentication Docs

Gemini CLI (Google)

Terminal

npm install -g @google/gemini-cli

Authentication options:

Method	Requirements	API Key Needed?	Free Tier
Google Login	Personal Google account	No	60 req/min, 1,000 req/day
API Key	Google AI Studio account	Yes	Same limits

server.ts

# Option 1: Login with Google account (recommended)
gemini auth login
# Opens browser for OAuth - follow the prompts

# Option 2: Use API key from Google AI Studio
export GEMINI_API_KEY="your-gemini-key"

Free Tier: With a personal Google account, you get access to Gemini 2.5 Pro with 1M token context window at no cost!

📖 Gemini CLI Authentication Docs

Qwen CLI (Alibaba)

Terminal

npm install -g qwen-code

Authentication options:

Method	Requirements	API Key Needed?	Free Tier
DashScope API	Alibaba Cloud account	Yes	2,000 req/day
Coding Plan	Qwen Coding subscription	Yes (different format)	Included

server.ts

# Get your API key from DashScope console
export DASHSCOPE_API_KEY="your-dashscope-key"

# For international users (outside China)
export OPENAI_BASE_URL="https://dashscope-intl.aliyuncs.com/compatible-mode/v1"

Regional Endpoints:

Singapore: dashscope-intl.aliyuncs.com

Virginia: dashscope-us.aliyuncs.com

Beijing: dashscope.aliyuncs.com

📖 Qwen API Docs

3. Verify Installation

bash

# Check Tetrad version
tetrad version

# Check CLI availability
tetrad status

# Diagnose any issues
tetrad doctor

4. Add to Claude Code CLI

bash

# Add Tetrad as MCP server (all projects)
claude mcp add --scope user tetrad -- npx @samoradc/tetrad serve

# Verify it's configured
claude mcp list

Alternative installation methods

bash

# Current project only
claude mcp add tetrad -- npx @samoradc/tetrad serve

# If installed via cargo
claude mcp add --scope user tetrad -- tetrad serve

Note: Tetrad is published on the MCP Registry for discoverability and documentation.

5. Alternative: Manual Configuration

Create or edit .mcp.json in your project root:

config.json

{
  "mcpServers": {
    "tetrad": {
      "type": "stdio",
      "command": "npx",
      "args": ["@samoradc/tetrad", "serve"],
      "env": {
        "OPENAI_API_KEY": "${OPENAI_API_KEY}",
        "GOOGLE_API_KEY": "${GOOGLE_API_KEY}",
        "DASHSCOPE_API_KEY": "${DASHSCOPE_API_KEY}"
      }
    }
  }
}

Or for global user configuration in ~/.claude.json (mcpServers section):

config.json

{
  "mcpServers": {
    "tetrad": {
      "type": "stdio",
      "command": "npx",
      "args": ["@samoradc/tetrad", "serve"]
    }
  }
}

How It Works

When you ask Claude Code to write code, Tetrad automatically validates it:

Code

You: "Create a function in Rust that calculates the average of a vector"

Claude Code:
1. Writes the code
2. Calls tetrad_review_code automatically
3. Tetrad sends to Codex, Gemini and Qwen for evaluation
4. Returns consolidated consensus from all 3 evaluators

Tetrad Response:
┌─────────────────────────────────────────────┐
│ DECISION: PASS ✓                            │
│ Score: 92/100                               │
│ Consensus: Yes (3/3 approved)               │
│                                             │
│ Votes:                                      │
│   • Codex:  Pass (95)                       │
│   • Gemini: Pass (90)                       │
│   • Qwen:   Pass (92)                       │
│                                             │
│ Suggestions:                                │
│   - Consider handling empty vector case     │
└─────────────────────────────────────────────┘

Claude Code: Saves the approved code

When Issues Are Found:

Code

Tetrad Response:
┌─────────────────────────────────────────────┐
│ DECISION: BLOCK ✗                           │
│ Score: 26/100                               │
│ Consensus: Yes (3/3 rejected)               │
│                                             │
│ Votes:                                      │
│   • Codex:  Fail (30) - division by zero    │
│   • Gemini: Fail (25) - no error handling   │
│   • Qwen:   Fail (25) - unsafe operation    │
│                                             │
│ Issues:                                     │
│   - Division by zero not handled            │
│   - Missing input validation                │
│   - No Result/Option return type            │
└─────────────────────────────────────────────┘

Claude Code: Fixes the code and resubmits

CLI Commands

server.ts

tetrad - Quadruple Consensus CLI for Claude Code

COMMANDS:
    init              Initialize configuration in current directory
    serve             Start the MCP server (used by Claude Code)
    status            Show CLI status (codex, gemini, qwen)
    config            Configure options interactively
    doctor            Diagnose configuration issues
    version           Show version
    evaluate          Evaluate code manually (without MCP)
    history           Show evaluation history from ReasoningBank
    export            Export patterns from ReasoningBank
    import            Import patterns into ReasoningBank

OPTIONS:
    -c, --config <FILE>    Configuration file (default: tetrad.toml)
    -v, --verbose          Verbose mode
    -q, --quiet            Quiet mode
    -h, --help             Show help

MCP Tools

When running as MCP server, Tetrad exposes 6 tools:

Tool	Description
`tetrad_review_plan`	Review implementation plans before coding
`tetrad_review_code`	Review code before saving
`tetrad_review_tests`	Review tests before finalizing
`tetrad_confirm`	Confirm agreement with received feedback
`tetrad_final_check`	Final verification before commit
`tetrad_status`	Check health of evaluators

Workflow Example

Code

1. Claude Code generates plan → tetrad_review_plan → Feedback
2. Claude Code implements   → tetrad_review_code → Feedback
3. Claude Code adjusts      → tetrad_confirm     → Confirmation
4. Claude Code finalizes    → tetrad_final_check → Certificate

Architecture

Read the full README →View source on GitHub →

Related MCP Servers

View all in Developer Tools View all alternatives

Adoption & maintenance

Factual signals from GitHub, npm, and our automated checks — not a rating.

GitHub stars

Stargazers on the source repository.

npm downloads

228

Package downloads in the last 30 days.

Last commit

7mo ago

Most recent push to the default branch.

Tools exposed

Callable tools this server registers over MCP.

Reviews

No reviews yet — be the first to share how this listing worked for you.

Frequently Asked Questions about Tetrad

Add the following block to your claude_desktop_config.json under mcpServers: "mcpServers": { "tetrad": { "command": "npx", "args": ["-y","@samoradc/tetrad"] } }

AllMCPs Directory Badge

Full Badge Customizer

Showcase your server listing on GitHub or your project documentation. Embed this dynamic SVG badge to highlight official listing status and live engagement.

Badge Style:

Live Dynamic SVG Preview

Markdown (GitHub README)

[![AllMCPs](https://allmcps.com/api/badge/tetrad?style=directory)](https://allmcps.com/mcp/tetrad)

HTML Embed

<a href="https://allmcps.com/mcp/tetrad"><img src="https://allmcps.com/api/badge/tetrad?style=directory" alt="Tetrad on AllMCPs" /></a>

Technical Specs & Signals

CategoryDeveloper Tools

5/9 checks healthy over the last 45d

49Quality signal: Fair · 49/100How this signal is calculated ▾

Server availabilityNot measured

Not scored for repo-hosted servers — we can't reach the running server, only its GitHub page. Hosted MCP endpoints are health-checked live.

Verified ownership10/20

Documentation & tools24/30

Adoption & activity3/15

Community engagement0/10

Supply-chain signal

No high-severity advisories surfaced by our automated scan.

Critical 0High 0Medium 0Low 0

Scanned 1d ago via OSV.dev · @samoradc/tetrad (npm)

★ Spotlight Slot

Feature Your MCP Server

Get maximum visibility for your server across our directory, search results, and detail pages.

Spotlight Your Server

Own this project?

Free dofollow backlink: add your website and place the AllMCPs badge on it — no claim needed. We detect it automatically and keep it verified as long as the badge stays live.

Claim & get free dofollow

Share & Embed

Add our SVG badge (dark/light directory styles) or embeddable widget to your site.

Explore more

More in 💻 Developer Tools →Best MCP servers for Developers →Alternatives to Tetrad →Install in Claude Desktop Install in Cursor Install in VS Code Setup guides for all 13 MCP clients