Open-Source Approach to Ensuring Quality with AI — Classmethod Releases AI-Assisted Test-Driven Development Framework “Tsumiki”

Classmethod, Inc. (Headquarters: Minato-ku, Tokyo; CEO: Satoshi Yokota;”Classmethod”) has officially released “Tsumiki,” an open-source framework designed to systematize and streamline the use of Anthropic’s AI agent-driven coding tool, “Claude Code.”

■ Background and Challenges

In recent years, the rise of AI-powered “vibe coding”—a development method where code is generated based on natural language instructions—has made it easier for even those with limited programming experience to build systems. However, in corporate development environments, the following serious issues have become apparent:

Not implemented as expected — Frequent rework due to ambiguous specifications
Works, but seems hard to maintain — Accumulation of technical debt due to lack of testing
Fine for simple demos, but risky for production — Lack of quality assurance processes

Over the past 12 months, Classmethod has worked with more than 40 client companies on AI-assisted development and discovered that solving these issues requires not only “pursuing smarter AI” but also “discipline in the development process.”

Additionally, through the use of Claude Code, many companies have expressed the following needs:

Adopt a systematic approach to Test-Driven Development (TDD)
Build a standardized workflow across the team
Establish a development process that ensures quality while leveraging AI
Eliminate disparities in individual prompt engineering skills

To meet these needs, Classmethod has systematized its accumulated expertise in AI-assisted test-driven development and released it as a framework.

■ Overview and Features of Tsumiki

Tsumiki enables the construction of reliable production-grade systems through a new development method called AI-assisted Test-Driven Development (AITDD), based on the principles of Specification First, Test First, and Quality First.

It goes beyond simply generating “working code” and enables efficient development of “clearly specified, test-protected, and maintainable production-quality systems” by fully leveraging AI capabilities.

Positioning of Tsumiki

Within the AI-driven development ecosystem, Tsumiki is positioned as follows:

Claude (AI model) → Claude Code (middleware) → Tsumiki (framework) → Industry Templates → Individual Applications

Tsumiki serves as a bridge to effectively utilize the powerful features of Claude Code in real-world development.

Differences Between AITDD and Conventional AI-Driven Development

AITDD combines traditional Test-Driven Development (TDD) with AI technology to enhance development efficiency.

Basic Development Cycle:

Requirements Expansion → Design → Task Breakdown → TDD Implementation
(Requirements Analysis → Write Test Case → Red → Green → Refactor → Verify)

Features of the Extended TDD Cycle:

Red (Write Test): Define the “expected behavior” as a test first
Green (Implementation): AI generates the minimal code needed to pass the test
Refactor (Improvement): AI optimizes the code for readability and efficiency
Verify (Validation): AI confirms that the implementation meets the requirements

Differences from Conventional AI-Driven Development:

Tsumiki ensures quality not just by generating code with AI, but also through:

Automatic Specification Generation and Management: Clarifies requirements and ensures consistency with implementation
Automated Code Review: Objective quality evaluation by AI

■ Key Components of Tsumiki

Tsumiki consists of the following main components:

1．Kairo Command Set: Provides a comprehensive development flow from requirements expansion to implementation

Automates requirements expansion, design, task breakdown, and implementation
Ensures consistent process management

2．TDD Command Set: Supports each step of test-driven development with AI

Implements the Red-Green-Refactor-Verify cycle
Automatically evaluates based on quality standards

3．Integrated Workflow

Automates development processes by combining multiple commands
Dedicated AITDD command sets (/kairo-* series, /tdd-* series)

■ Public Information

Repository: https://github.com/classmethod/tsumiki

License: MIT License (Commercial use permitted)

■ Future Outlook

Tsumiki is also planned to be expanded with industry-specific templates. Specialized templates tailored to the characteristics of various industries—such as finance, healthcare, manufacturing, and retail—will be provided sequentially.

About Classmethod, Inc.

Classmethod, Inc. is a technology partner supporting corporate digital transformation (DX), with a focus on cloud-native technologies including Amazon Web Services (AWS), data analytics, mobile, IoT, and AI/machine learning.

In AWS consulting, Classmethod has been recognized as a top-tier partner continuously since 2015, and has received the “AWS Consulting Partner of the Year” award recognizing the best domestic partner four times. In 2022, Classmethod received the “SI Partner of the Year” award as the global top partner, and was again named a finalist in 2023, establishing Classmethod as one of the world’s leading AWS partners. To date, Classmethod has supported approximately 5,000 companies and assisted with the management and construction of over 40,000 AWS accounts. Classmethod also places great emphasis on a culture of technical knowledge sharing by its engineers. Its owned media platform “DevelopersIO”, features over 50,000 technical articles, and we also operate “Zenn,” a knowledge-sharing platform for developers, contributing to the growth of the broader technical community. Under the mission of “empowering creativity through innovative ideas and advanced technical expertise,” Classmethod will continue to propose optimal technologies that enhance the business value of its customers.

Headquarters: 26F Hibiya Fort Tower 1-1-1 Nishishimbashi Minato-ku, Tokyo
CEO: Satoshi Yokota
Business: Cloud migration, development of big data infrastructure and mobile applications, technical assistance on AI/machine learning and LINE based software development

Official Website (Japanese): https://classmethod.jp/
Official Website (English): https://classmethod.jp/english/
DevelopersIO (tech blog): https://dev.classmethod.jp/en/
Facebook: https://www.facebook.com/classmethod/
Official YouTube channel: https://www.youtube.com/c/classmethod-yt/

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