Yakusoku Keeper

A rule-based prompting MCP server that enforces consistent LLM behavior through input count and time-based triggers.

Yakusoku (約束) means "promise" in Japanese - this tool helps Claude Code keep its promises by automatically applying configured rules at specified intervals.

Features

• 🎯 Automatic Rule Application: Rules are automatically triggered based on input count or elapsed time

• 🔄 Dynamic Rule Management: Add, remove, and modify rules in real-time

• ⚙️ Flexible Configuration: Support for user-level and project-specific rules

• 📊 Multiple Trigger Types: First-time, every N inputs, and every N minutes rules

• 🔌 Claude Code Integration: Seamless MCP server integration with Claude Code

Related MCP server: mcp-codex-dev

Quick Start

Installation

1. Clone the repository:

git clone https://github.com/ShigeruWakida/YakusokuKeeper.git
cd YakusokuKeeper

2. Install dependencies:

pip install -r requirements.txt

3. Test the server:

python yakusoku_keeper.py

Claude Code Configuration

Add the server using the Claude Code CLI:

claude mcp add yakusoku_keeper --scope project -- python /path/to/YakusokuKeeper/yakusoku_keeper.py

Or manually add this to your Claude Code MCP settings:

{
  "mcpServers": {
    "yakusoku_keeper": {
      "type": "stdio",
      "command": "python",
      "args": ["/path/to/YakusokuKeeper/yakusoku_keeper.py"],
      "env": {}
    }
  }
}

How It Works

Rule Types

• first: Triggers on the very first interaction

• every_N_inputs: Triggers every N user inputs (e.g., every 5 interactions)

• every_N_minutes: Triggers after N minutes have elapsed since the last trigger

Configuration Files

Yakusoku Keeper uses a two-tier configuration system:

• ~/.yakusoku/yakusoku_config.yml: Global rules (created commented-out by default)

• .yakusoku/project.yml: Project-specific rules (created active by default)

Example Configuration

# --- First time rules ---
first:
  - At the beginning of the response, insert the string that follows "say".
  - say Hello! I am Yakusoku Keeper.
  - Generate code using the K&R coding style.
  - Use only < and <= operators for all comparisons.
  - Read and follow ./docs/README_CODING_STANDARDS.md
  - When using replace_symbol_body, insert_after_symbol, or insert_before_symbol, you MUST present the code block—preferably in diff format—and you MUST obtain explicit approval before applying any change.

# --- Input count based rules ---
every_5_inputs:
  - Generate code using the K&R coding style.
every_10_inputs:
  - Use only < and <= operators for all comparisons.
  - When using replace_symbol_body, insert_after_symbol, or insert_before_symbol, you MUST present the code block—preferably in diff format—and you MUST obtain explicit approval before applying any change.

# --- Time based rules ---
every_60_minutes:
  - Read and follow ./docs/README_CODING_STANDARDS.md

MCP Tools

Core Tools

• get_rules(): Returns rules that match current conditions (called automatically)

• reset(): Resets input counters and time triggers

• initial_instructions(): Provides high-priority instructions to Claude Code

Rule Management Tools

• add_rule(rule_type, rule_content, target, value): Dynamically add new rules

• remove_rule(rule_type, rule_content, target, value): Remove existing rules

Examples

# Add a first-time rule
add_rule("first", "Always be polite and helpful")

# Add an input-based rule (every 3 inputs)
add_rule("every_N_inputs", "Check code for best practices", value=3)

# Add a time-based rule (every 30 minutes)
add_rule("every_N_minutes", "Suggest taking a break", value=30)

# Remove a rule
remove_rule("first", "Always be polite and helpful")

Project Structure

YakusokuKeeper/
├── yakusoku_keeper.py    # Main MCP server
├── README.md           # This file
├── requirements.txt    # Dependencies
├── LICENSE            # MIT License
└── .yakusoku/          # Project configuration (auto-created)

Use Cases

• Coding Standards: Automatically remind about code style requirements

• Documentation: Prompt for documentation at regular intervals

• Code Review: Trigger quality checks every few interactions

• Break Reminders: Suggest breaks during long coding sessions

• Greeting Messages: Consistent welcome messages for new sessions

Combo: YakusokuKeeper + mcp-win-toast

mcp-win-toast is an MCP server that lets AI assistants send Windows toast notifications and dialog boxes. By combining it with YakusokuKeeper, you can build a self-managing AI assistant that notifies you at the right moments — automatically, without being asked.

Break Reminder

Add a time-based rule to remind you to take a break every 30 minutes, delivered as a toast notification.

every_30_minutes:
  - "Call show_toast with title 'Break Time' and message 'You have been working for 30 minutes. Stand up and stretch!'"

Progress Report at Regular Intervals

Have Claude automatically summarize what it has done every 10 interactions and notify you.

every_10_inputs:
  - "Summarize what you have accomplished so far in 2-3 bullet points, then call show_toast with title 'Progress Report' and the summary as the message."

Critical File Protection

Show a blocking dialog for confirmation whenever Claude is about to modify important files.

first:
  - "Before editing any file matching *.env, *.config, or docker-compose.*, always call show_dialog with title 'Confirm Edit' and a message describing which file you are about to modify. Wait for the user to acknowledge before proceeding."

Session Duration Warning

Warn the user with a dialog box after a long session so they can decide whether to continue.

every_60_minutes:
  - "Call show_dialog with title 'Long Session' and message 'You have been working for over an hour. Would you like to wrap up or continue?' to check in with the user."

Contributing

1. Fork the repository

2. Create a feature branch (git checkout -b feature/amazing-feature)

3. Commit your changes (git commit -m 'Add amazing feature')

4. Push to the branch (git push origin feature/amazing-feature)

5. Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• Built with FastMCP for MCP server implementation

• Designed for seamless integration with Claude Code