How to use the Commit Context Tracer agent skill

What does the commit-context skill make the agent do?

Agent skills are instruction packages that an AI agent loads when a request matches them. This one handles questions such as "why is this code here", "what was the agent doing when this changed" or "who wrote this".

The agent first uses git to find the commit that last changed the location you named. It then calls the memory_commit_lookup tool with the full commit SHA to find any linked agent session. It reports the commit details and the session summary, and it avoids guessing intent when no session is recorded.

• Works on a file, a function, or a line range.
• Reports the commit: SHA, short SHA, branch, author and message.
• Reports linked sessions: id, project, start and end times, observation count and summary.
• Pulls high-importance observations through memory_recall when that tool is available.

How do you install the commit-context skill?

Download the ZIP for the skill from this page and unzip it. You can install it for yourself or for a single project.

For a personal install, unzip it into ~/.claude/skills/. For a project-only install, unzip it into the project's .claude/skills/ folder. Alternatively, in the Claude apps, open Settings, then Capabilities, then Skills, and upload the skill there.

• Personal: ~/.claude/skills/
• Project: .claude/skills/ inside your repository
• Claude apps: Settings → Capabilities → Skills, then upload

What do you need before it works?

The skill needs git installed and your project must be a git repository. It also needs the agentmemory plugin, which provides the memory_commit_lookup and memory_recall tools. Without the plugin, the lookup step is unavailable.

The skill runs scripts and does not use the network, according to its listing. Review the files in the ZIP if you want to confirm what runs on your machine.

• git installed and the project inside a git repository
• agentmemory plugin providing memory_commit_lookup and memory_recall

How do you trigger the skill with a natural request?

You do not need a special command. Ask in plain language and include the location. Good examples are "Why is this retry loop here?" with lines selected, or "What was the agent doing when validateScope changed?" The skill also accepts an argument in the form [file, function, or line].

Under the hood, the agent finds the commit SHA with git blame for a line range, git log -L for a function, or git log -n 1 for a bare file path, then runs the lookup.

• Line range: git blame -L <start>,<end> <file>
• Function: git log -L :<function>:<file>
• Bare file: git log -n 1 -- <file>

What does a real lookup look like?

In the worked example, a reader asks why a retry loop exists in lines 40 to 52 of refresh.ts. git blame returns the commit SHA, and the lookup returns the commit on the main branch with its message and one linked session. The agent then presents the commit and quotes the session summary and observation count from the lookup response.

If the lookup returns a null commit, the skill reports that the commit predates session linking and does not invent a reason for the change.

• Expected output starts with the short SHA, branch, author and commit message.
• The linked session line gives the session id, title and observation count.

What are the limits and safety notes?

The skill only reports what git and the lookup return. It is not a source of intent beyond what recorded observations state. When no session is linked, you get the diff context from git show and nothing more.

Because the skill runs scripts, read its files before installing if you handle sensitive repositories. The listing says it does not use the network.

• Commits made before session linking existed have no recorded session.
• Repositories without the agentmemory memory system will not have memory_commit_lookup, so you only get plain git output.
• Do not expect reasoning for changes that no session recorded.

What tips help you get better results?

Select the exact lines or name the function, because a precise location gives git blame a precise commit. If the agent says a tool is missing, check the troubleshooting guide bundled with the skill; it covers the case where memory_commit_lookup is unavailable.

• Give a line range or function name rather than a whole file.
• Use commit-history to list many agent-linked commits at once.
• Use recall to dig deeper into a linked session's observations.
• Check TROUBLESHOOTING.md if the lookup tool is not available.