Automated TDD enforcement for Claude Code.

TDD Guard monitors file operations in real-time and blocks any changes that violate TDD principles. By analyzing test results, todos, and code changes, it ensures Claude Code follows the red-green-refactor cycle without manual reminders.

Click to watch TDD Guard in action

• Focus on solving problems - TDD Guard enforces the rules while you design solutions
• Save context for what matters - No more TDD instructions cluttering your CLAUDE.md
• Works with your stack - TypeScript, JavaScript, Python, and PHP today. More languages coming soon
• Control without context switches - Toggle with tdd-guard on/off mid-session
• Flexible validation - Use local Claude or configure Anthropic API

• Node.js 18+
• Test Runner:
  • JavaScript/TypeScript: Vitest or Jest
  • Python: pytest
  • PHP: PHPUnit 9.x, 10.x, 11.x, or 12.x

npm install -g tdd-guard

TDD Guard needs to capture test results from your test runner. Choose your language below:

npm install --save-dev tdd-guard-vitest

import { defineConfig } from 'vitest/config'
import { VitestReporter } from 'tdd-guard-vitest'

export default defineConfig({
  test: {
    reporters: [
      'default',
      new VitestReporter('/Users/username/projects/my-app'),
    ],
  },
})

npm install --save-dev tdd-guard-jest

import type { Config } from 'jest'

const config: Config = {
  reporters: [
    'default',
    [
      'tdd-guard-jest',
      {
        projectRoot: '/Users/username/projects/my-app',
      },
    ],
  ],
}

export default config

pip install tdd-guard-pytest

[tool.pytest.ini_options]
tdd_guard_project_root = "/Users/username/projects/my-app"

composer require --dev tdd-guard/phpunit

<listeners>
    <listener class="TddGuard\PHPUnit\TddGuardListener">
        <arguments>
            <string>/Users/username/projects/my-app</string>
        </arguments>
    </listener>
</listeners>

<extensions>
    <bootstrap class="TddGuard\PHPUnit\TddGuardExtension">
        <parameter name="projectRoot" value="/Users/username/projects/my-app"/>
    </bootstrap>
</extensions>

Use the /hooks command in Claude Code:

1. Type /hooks in Claude Code
2. Select PreToolUse - Before tool execution
3. Choose + Add new matcher...
4. Enter: Write|Edit|MultiEdit|TodoWrite
5. Select + Add new hook...
6. Enter command: tdd-guard
7. Choose where to save (Project settings recommended)

Tip: Also configure:

• Quick commands for tdd-guard on/off
• Session clearing for automatic cleanup on new sessions
• ESLint integration for automated refactoring support

TDD Guard supports two AI models for validation:

Uses your existing Claude Code authentication. No additional setup required.

Direct API access provides faster validation.

Setup:

1. Get an Anthropic API key from console.anthropic.com
   • Note: This is separate from Claude Code and requires Anthropic API credits
   • Uses token-based billing instead of Claude Code subscription
2. Set environment variables:

export TDD_GUARD_ANTHROPIC_API_KEY=your_api_key_here
export MODEL_TYPE=anthropic_api

Note: TDD Guard uses the TDD_GUARD_ANTHROPIC_API_KEY environment variable (not the standard ANTHROPIC_API_KEY) to avoid conflicts with other Anthropic SDK usage in your project.

As stated in the Claude Code Hooks documentation:

Hooks execute shell commands with your full user permissions without confirmation. You are responsible for ensuring your hooks are safe and secure. Anthropic is not liable for any data loss or system damage resulting from hook usage.

We share this information for transparency. Please read the full security considerations before using hooks.

TDD Guard runs with your user permissions and has access to your file system. We follow security best practices including automated security scanning, dependency audits, and test-driven development. Review the source code if you have security concerns.

• Not tested with multiple concurrent sessions in the same project

• Add support for more testing frameworks (Mocha, unittest, etc.)
• Add support for additional programming languages (Go, Rust, Java, etc.)
• Encourage meaningful refactoring opportunities when tests are green
• Add support for multiple concurrent subagents per project

See DEVELOPMENT.md for setup instructions and development guidelines.

Contributions are welcome! Feel free to submit issues and pull requests.

Contributors:

• Python/pytest support: @Durafen
• PHP/PHPUnit support: @wazum

• Configuration Guide - Environment variables, model options, and troubleshooting
• Architecture Decision Records - Technical design decisions and rationale

MIT