# Git Commit Signoff > Use whenever creating, amending, rebasing, squashing, fixing up, or modifying Git commits in this repository. Ensures every commit created or changed by the AI includes a Signed-off-by trailer using Git's built-in signoff mechanism and a Co-Authored-By trailer identifying the AI tool. - Skill: `lakesoul-io/git-commit-signoff` (Agent Skill) - Install (CLI): `npx skillmds@latest add lakesoul-io/git-commit-signoff` - Raw SKILL.md: https://api.skillmd.com/api/skills/lakesoul-io/git-commit-signoff/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: lakesoul-io (https://skillmd.com/u/lakesoul-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/lakesoul-io/git-commit-signoff --- # Git Commit Sign-off Skill This repository requires Git commits created or modified by the AI to include: 1. a `Signed-off-by` trailer; and 2. a `Co-Authored-By` trailer identifying the AI tool that created or modified the commit. Always use Git's built-in sign-off mechanism for `Signed-off-by` instead of manually typing the sign-off trailer. ## Core rule When creating a new commit, always use one of: ```bash git commit -s ``` ```bash git commit --signoff ``` When committing with an inline message, use: ```bash git commit -s -m "commit message" ``` Do not create commits with plain `git commit` unless the commit message already contains a valid `Signed-off-by` trailer and the user explicitly asked not to amend it. Every commit created or modified by the AI must also include an AI co-author trailer, for example: ```text Co-Authored-By: Claude Opus 4.7 ``` Use the actual AI tool name and email identity configured for this repository or requested by the user. Do not invent an AI identity. ## Why this matters `git commit -s` appends a trailer like: ```text Signed-off-by: Name ``` The identity comes from Git configuration: ```bash git config user.name git config user.email ``` Do not invent or manually write a sign-off identity. Let Git generate it. The AI co-author trailer makes it clear that an AI tool helped create or modify the commit. ## AI co-author identity Before creating or modifying commits, determine which AI co-author trailer should be used. If the repository, user, or existing contribution policy specifies an AI co-author identity, use that exact identity. Examples: ```text Co-Authored-By: Claude Opus 4.7 ``` ```text Co-Authored-By: ChatGPT ``` If no AI co-author identity is configured or provided, ask the user which AI co-author trailer to use before creating the commit. Do not guess the AI tool name, version, or email address. ## Before committing Before creating a commit, check what will be committed: ```bash git status --short git diff --cached ``` If nothing is staged, either stage the intended files or ask the user what should be included. When staging changes, prefer explicit paths: ```bash git add path/to/file ``` Avoid broad staging like this unless the user clearly wants all changes committed: ```bash git add . ``` ## Creating a signed-off commit with AI co-author trailer Use: ```bash git commit -s ``` or with a message: ```bash git commit -s -m "component: short description" ``` For multi-line commit messages, include the AI co-author trailer as a commit message paragraph: ```bash git commit -s \ -m "component: short description" \ -m "Longer explanation of the change." \ -m "Co-Authored-By: Claude Opus 4.7 " ``` If using an editor, let `git commit -s` add the `Signed-off-by` trailer, then add the AI co-author trailer to the trailer block. ## Amending the latest commit When amending the latest commit, always preserve or add sign-off and preserve or add the AI co-author trailer. If the message may be edited: ```bash git commit --amend --signoff ``` If the message should stay unchanged and already contains the correct AI co-author trailer: ```bash git commit --amend --signoff --no-edit ``` If the latest commit is missing the AI co-author trailer, amend the message and add it: ```bash git commit --amend --signoff ``` If the latest commit already has a `Signed-off-by` trailer, `--signoff` may add another trailer depending on the current identity and message state. Check the final message after amending. ## Fixing a commit that missed sign-off or AI co-author If the latest commit was accidentally created without sign-off, run: ```bash git commit --amend --signoff --no-edit ``` If the latest commit was accidentally created without the AI co-author trailer, run: ```bash git commit --amend ``` Then add the correct trailer, for example: ```text Co-Authored-By: Claude Opus 4.7 ``` Finally verify: ```bash git show -s --format=full ``` ## Verifying trailers After creating or modifying a commit, verify the latest commit contains both required trailers: ```bash git show -s --format=full ``` or: ```bash git log -1 --pretty=full ``` Look for lines like: ```text Signed-off-by: Name Co-Authored-By: Claude Opus 4.7 ``` ## Rebasing, squashing, fixing up, or rewording When modifying existing commits through rebase, ensure every resulting commit still has sign-off and AI co-author trailers. For an interactive rebase: ```bash git rebase -i HEAD~N ``` If a commit needs sign-off, mark it as `edit`, then run: ```bash git commit --amend --signoff --no-edit git rebase --continue ``` If a commit needs the AI co-author trailer, mark it as `reword` or `edit`, then add the correct trailer to the commit message. Repeat until all edited commits have the required trailers. If squashing commits, ensure the final squashed commit message contains both: ```text Signed-off-by: Name Co-Authored-By: Claude Opus 4.7 ``` Prefer finishing the squash, then running: ```bash git commit --amend --signoff ``` and adding the AI co-author trailer if it is missing. ## Force push safety If a signed-off amend or rebase changes commits that were already pushed, do not use plain force push. Use: ```bash git push --force-with-lease ``` Only push when the user has asked to push or has clearly authorized pushing. ## Missing Git identity If Git cannot create the sign-off because `user.name` or `user.email` is not configured, stop and report the issue. Check with: ```bash git config user.name git config user.email ``` Suggest configuring them with: ```bash git config user.name "Your Name" git config user.email "you@example.com" ``` For global configuration: ```bash git config --global user.name "Your Name" git config --global user.email "you@example.com" ``` Do not guess the user's identity. ## Do not manually type sign-off Avoid this unless the user explicitly instructs it: ```text Signed-off-by: Name ``` Prefer: ```bash git commit -s ``` or: ```bash git commit --amend --signoff ``` The AI co-author trailer may be typed manually because Git does not generate it automatically. ## Commit message guidance Use concise, conventional commit messages when possible. Good examples: ```text io: add vortex file sink test ``` ```text storage: handle spill writer cleanup ``` ```text tests: add coverage for vortex sink writes ``` Avoid vague messages: ```text fix ``` ```text update ``` ```text changes ``` ## Final checklist Before finishing any commit-related task: 1. Confirm the intended files are staged. 2. Create or amend the commit using `-s` or `--signoff`. 3. Add the required AI co-author trailer. 4. Verify the latest commit has `Signed-off-by`. 5. Verify the latest commit has the correct `Co-Authored-By` trailer for the AI tool. 6. If history was rewritten and the user asked to push, use `git push --force-with-lease`. 7. Do not remove existing sign-off or co-author trailers unless explicitly requested.