# How to Use the caveman-commit Skill for Conventional Commit Generation > Learn how to use caveman-commit to effortlessly generate Conventional Commit messages from staged diffs or natural language prompts. Streamline your Git workflow today. - Repository: [Julius Brussee/caveman](https://github.com/JuliusBrussee/caveman) - Tags: how-to-guide - Published: 2026-08-22 --- **The caveman-commit skill generates Conventional Commit messages from staged diffs or natural language prompts via the `/caveman-commit` slash command, outputting formatted text without executing git commands.** The **caveman-commit** skill is a self-contained commit message generator distributed within the [JuliusBrussee/caveman](https://github.com/JuliusBrussee/caveman) repository. Located in the `skills/caveman-commit` directory, it transforms git diffs or descriptive text into standardized Conventional Commit messages. The skill operates entirely through LLM instructions defined in its source files, ensuring consistent formatting across projects without performing any actual git operations. ## Activating the caveman-commit Skill ### Slash Command Invocation The primary interface is the `/caveman-commit` slash command registered in the global help table via [`skills/caveman-help/SKILL.md`](https://github.com/JuliusBrussee/caveman/blob/main/skills/caveman-help/SKILL.md). When invoked, the skill reads the staged diff or provided context and returns a formatted message ready for manual commit. ```text /caveman-commit ``` ### Natural Language Triggers The skill activates on conversational phrases without requiring the slash command. According to the instruction set in [`skills/caveman-commit/SKILL.md`](https://github.com/JuliusBrussee/caveman/blob/main/skills/caveman-commit/SKILL.md), trigger phrases include "write a commit", "commit message", or "generate commit". ```text Please write a commit for the new user-profile endpoint. ``` ## Architecture and Source Files The skill's deterministic behavior is defined across three authoritative files: - **[`skills/caveman-commit/SKILL.md`](https://github.com/JuliusBrussee/caveman/blob/main/skills/caveman-commit/SKILL.md)** – Contains the front-matter (`name`, `description`) and the complete LLM-facing instruction set. This file defines trigger phrases, formatting rules, and the strict boundary that the skill only *generates* messages without running `git commit`. - **[`skills/caveman-commit/README.md`](https://github.com/JuliusBrussee/caveman/blob/main/skills/caveman-commit/README.md)** – Provides human-readable documentation explaining the skill's purpose and usage examples. - **[`skills/caveman-help/SKILL.md`](https://github.com/JuliusBrussee/caveman/blob/main/skills/caveman-help/SKILL.md)** – Registers the `/caveman-commit` command in the UI help table, enabling discoverability. ## Conventional Commit Format Requirements The skill enforces strict Conventional Commit standards as defined in its [`SKILL.md`](https://github.com/JuliusBrussee/caveman/blob/main/SKILL.md) instruction set. ### Subject Line Rules The subject must follow the format `(): `. The implementation enforces a **hard limit of 72 characters**, with a strong preference for **≤50 characters** when possible. ### Body Content Logic The body is intentionally omitted unless the change motivation is non-obvious, a breaking change exists, or additional context (such as security fixes or migration notes) is required. This keeps the output minimal and scannable. ## Usage Examples ### Standard Feature Commit When processing a diff for a new API endpoint, the skill outputs: ```text feat(api): add GET /users/:id/profile Mobile client needs profile data without the full user payload to reduce LTE bandwidth on cold-launch screens. Closes #128 ``` The output appears as a markdown code block for direct copy-paste into your terminal. ### Breaking Change Detection When the diff or prompt indicates a breaking change, the skill automatically appends the `!` marker after the scope and includes a `BREAKING CHANGE:` trailer in the body. **Input:** ```text Rename the old orders API to the new checkout API. ``` **Output:** ```text feat(api)!: rename /v1/orders to /v1/checkout BREAKING CHANGE: clients on /v1/orders must migrate to /v1/checkout before 2026-06-01. Old route returns 410 after that date. ``` ## Safety and Composability Design The **caveman-commit** skill maintains strict **no side effects** boundaries. As implemented in [`skills/caveman-commit/SKILL.md`](https://github.com/JuliusBrussee/caveman/blob/main/skills/caveman-commit/SKILL.md), it only outputs markdown-formatted code blocks containing the commit message. It never stages files, executes `git commit`, or amends existing history. This design ensures the skill remains safe to run in any repository state and composable with other automation workflows. ## Summary - The **caveman-commit** skill generates Conventional Commit messages via `/caveman-commit` command or natural language triggers like "write a commit". - Source instructions live in [`skills/caveman-commit/SKILL.md`](https://github.com/JuliusBrussee/caveman/blob/main/skills/caveman-commit/SKILL.md) with UI integration through [`skills/caveman-help/SKILL.md`](https://github.com/JuliusBrussee/caveman/blob/main/skills/caveman-help/SKILL.md). - Enforces strict 72-character limits and standard `()` formatting per Conventional Commit specifications. - Automatically handles breaking changes with `!` notation and `BREAKING CHANGE` trailers when detected. - Produces only text output without executing git commands, ensuring safe, composable operation. ## Frequently Asked Questions ### How do I trigger the caveman-commit skill? You can invoke the skill using the `/caveman-commit` slash command or by using natural language phrases like "write a commit" or "generate commit message" in your prompt. The skill detects these triggers via the instruction set defined in [`skills/caveman-commit/SKILL.md`](https://github.com/JuliusBrussee/caveman/blob/main/skills/caveman-commit/SKILL.md), processing either staged diffs or your provided description. ### What commit format does caveman-commit use? The skill generates messages following the Conventional Commit specification with the format `(): `. It enforces a hard limit of 72 characters for the subject line and automatically adds breaking change indicators when detected in the diff or description, ensuring consistent project history. ### Does caveman-commit execute git commands? No. The skill is designed with a strict no-side-effects policy as defined in its source code at [`skills/caveman-commit/SKILL.md`](https://github.com/JuliusBrussee/caveman/blob/main/skills/caveman-commit/SKILL.md). It only generates and outputs the commit message text within a markdown code block. You must manually copy the output and run `git commit` yourself, ensuring full control over the commit process. ### Where is the caveman-commit skill configuration stored? The behavioral configuration and LLM instructions reside in [`skills/caveman-commit/SKILL.md`](https://github.com/JuliusBrussee/caveman/blob/main/skills/caveman-commit/SKILL.md) within the JuliusBrussee/caveman repository. This file contains the complete instruction set including trigger phrases, formatting rules, and the explicit restriction against executing git commands, making the skill self-contained and portable.