Mods
User-written functions that change how AI models like Claude Code behave.
Mods are like small plugins or custom instructions you can write for certain AI tools. They allow you to change how the AI responds or what actions it can take.
For example, with Claude Code, you can write a mod that tells it how to format code snippets or how to interact with specific programming tools. This makes the AI more useful for your particular tasks.
Mods are user-defined functions that extend or alter the behavior of a large language model, particularly in specialized applications like code generation or tool use. These functions can intercept and modify model inputs, outputs, or tool calls, enabling custom logic, data transformations, or specialized integrations.
For instance, Anthropic's Claude Code allows users to write mods that define custom functions. These functions can influence how Claude Code processes prompts, generates code, or decides which external tools to use, offering a way to tailor the model's functionality without retraining the base model.
Anthropic is highlighting how users can customize Claude Code's behavior through custom functions. This allows for more tailored AI interactions and specific task automation, showing a trend towards user-driven AI modification.
- Mods in Claude Code: change how Claude Code worksAnthropic · Claude on YouTube ·
- Anthropic Claude
- Anthropic's Claude Code allows users to write functions, called mods, to change how the AI operates, including its tool use and responses.
- Fine-tuning
- Fine-tuning retrains a model on new data, changing its core knowled
- Plugins
- Plugins are often pre-built tools an AI can call, whereas mods are typi
- Prompt engineering
- Prompt engineering involves crafting input text to guide the
The concept of user-defined modifications to AI behavior has roots in software development's extensibility through plugins and custom scripts. For LLMs, this is evolving into specific features like function calling and custom tool integrations.
Explore the documentation for Anthropic's Claude Code to find examples of custom functions. Try to imagine writing a simple function that tells Claude how to always format Python code with a specific linter.
The Playbook: reusable how-tos, prompts, configs and tips pulled out of the news.
- ToolClaude Code Mods for Customizing Claude Code BehaviorCustom functions that alter Claude Code's rendering, prompt inputs, and tool calls. · 15 min
- PromptRole-play a student struggling with math for AI tutor simulationSimulate a student's math struggles and uncertainty for AI tutor evaluation. · 5 min
- TemplateReusable workflow templates for healthcare teamsTeams can create and share templates for common workflows like documentation or prior authorizations. · 15 min
- TemplateTemplate for building an AI tool tailored to your workA structured approach to defining and building a custom AI tool for specific business needs. · 15 min
- TemplateEvals CSV prompt list for agent skillsA CSV file template for listing prompts used in evaluating agent skills. · 20 min
Questions people ask
- Are mods the same as fine-tuning?
- No, mods are external instructions that guide an existing model's behavior, while fine-tuning involves retraining the model on new data to change its underlying knowledge or capabilities.
- Can I write mods for any AI?
- Currently, mod capabilities are specific to certain AI products and applications, like Anthropic's Claude Code. Availability varies across different AI labs and their offerings.
First seen on Subvolts Oct 5, 2026. Updated Oct 12, 2026. Written by an AI model from the items above and reviewed against them weekly; report an error.