author-contributions

A method for finding every file a particular author changed on one Git branch compared with another. It follows changes even when files were renamed.

In plain words
What is it for?
Use it before a merge or review to identify an author’s direct contributions and contributions made through renamed files. It can produce a table with the change type, file path, and line counts.
Why use it?
It gives a reliable authorship audit without overlooking work that moved between files. It also reports how many lines each file gained or lost.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/microsoft/vscode/author-contributions
Any agent
npx skills add microsoft/vscode --skill author-contributions
Clone the repo
git clone --depth 1 https://github.com/microsoft/vscode

Made for: Claude Code, Codex.

Per session 68 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,774 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00068 $0.01774
Opus 5 $0.00034 $0.00887
Sonnet 5 $0.00014 $0.00355
Haiku 4.5 $0.00007 $0.00177

Measured 2d ago against content hash 0b8c88378e18, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

author-contributions scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Runs shell commandslowCapability

Expected in a hook, worth knowing in a rule or an instructions file.

commits = subprocess.check_output(
Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.github/skills/author-contributions/SKILL.md · 187 lines

How it starts

The opening of the file, as written. The whole thing — 187 lines — stays where its author put it; the contents beside it link to each section on GitHub.

When asked to find all files a specific author contributed to on a branch (compared to main or another upstream), follow this procedure. The goal is to produce a simple table that both humans and LLMs can consume.

Run as a Subagent

This skill involves many sequential git commands. Delegate it to a subagent with a prompt like:

Find every file that author "Full Name" contributed to on branch <branch> compared to <upstream>. Trace contributions through file renames. Return a markdown table with columns: Status (DIRECT or VIA_RENAME), File Path, and Lines (+/-). Include a summary line at the end.

Procedure

1. Identify the author's exact git identity

git log --format="%an <%ae>" <upstream>..<branch> | sort -u

Match the requested person to their exact --author= string. Do not guess — short usernames won't match full display names (resolve via git log or the GitHub MCP get_me tool).

2. Collect all files the author directly committed to

git log --author="<Exact Name>" --format="%H" <upstream>..<branch>

For each commit hash, extract touched files:

git diff-tree --no-commit-id --name-only -r <hash>

Union all results into a set (author_files).

3. Build rename map across the entire branch

For every commit on the branch (not just the author's), extract renames:

git diff-tree --no-commit-id -r -M <hash>

Parse lines with R status to build a map: new_path → {old_paths}.

4. Get the merge diff file list

git diff --name-only <upstream>..<branch>

These are the files that will actually land when the branch merges.

5. Classify each file in the merge diff

For each file in step 4:

  • If it's in author_filesDIRECT
  • Else, walk the rename map transitively (follow chains: current → old → older) and check if any ancestor is in author_filesVIA_RENAME
  • Otherwise → not this author's contribution

6. Get diff stats

git diff --stat <upstream>..<branch> -- <file1> <file2> ...

Read the full file on GitHub · 187 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 187 lines · 68 tokens per session scan A 0b8c88378e18

Subscribe to this mod's changes

author-contributions is a skill published in the GitHub repository microsoft/vscode (190,384 stars, last pushed today), licensed MIT. It adds 68 tokens to every session and 1,774 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 1 finding (runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories