Repo Catchup

repo-catchup

Report what changed in the current repository over a date range. The reply has one executive-summary sentence, then a table with one row per commit. The skill always reads the repository it runs in. It takes no separate repository argument.

On a GitHub remote, with gh installed and authenticated, a row backed by a merged pull request links to that pull request. A row with no pull request still links to its bare commit. On any other host, or with gh missing or unauthenticated, every row falls back to a plain, non-clickable hash.

With a CODEOWNERS file present at the repository's root, .github/, or docs/, rows group by team. A commit's team is whichever one owns the majority of its touched files. A commit matching no team's rule falls back to its own author. With no CODEOWNERS file at any of the three locations, every row falls back to its own author's name.

When to use

• The user types /repo-catchup, with or without --from/--to.
• The user asks, in plain language, to catch up on this repository. This includes a request to summarize or review recent changes.
• Example requests: "catch me up on this repo," "what changed here recently," "summarize commits since 2026-08-01".

When not to use

• When the current directory is not a git repository, say so plainly and stop. Do not guess at another directory.
• When the user names a different repository to report on, decline. Suggest they run this skill from that repository instead. This skill only reads the one it runs in.
• When the user asks for a report scoped to one contributor or team, decline that scope. The same applies to a request that flags risk or breaking changes. This skill reports every contributor over the range, plain and descriptive, with no scoping flag and no judgment call.

Dependencies

Requires node to run the two bundled scripts named in Delegation below.

The bundled scripts also need an authenticated gh CLI for one path only: linking a row to its merged GitHub pull request, or to its bare commit, on a GitHub remote. No other part of this skill needs gh. When gh is missing or unauthenticated, or the remote is not GitHub, the scripts skip that enrichment on their own. The report still returns in full, with a plain hash in the Ref column instead.

Argument grammar

Scan args for two optional flags, in any order:

• --from <boundary>
• --to <boundary>

Each <boundary> value accepts one of three forms. The skill resolves the value in this order:

1. An absolute date in YYYY-MM-DD form.
2. A relative phrase, anchored to today. Recognized phrases are today, yesterday, last week, last month, and last year. A numeric phrase also works, for example 3 days ago, 2 weeks ago, or 4 months ago.
3. A git tag or branch name. The skill resolves it to that ref's own commit date.

The two flags resolve on their own. One side can use an absolute date. The other side can use a relative phrase or a ref.

When a value matches none of the three forms, the bundled script raises an error that names the value. Relay that error to the user plainly and stop. Do not guess a fallback range.

When the request gives no boundary for a flag, leave that flag out. Do not guess a value.

A boundary value can contain spaces, for example last week or 3 days ago. Keep it as one shell argument. Quote it in the subagent brief, for example --from "3 days ago".

Delegation

Call the Agent tool with:

• subagent_type: "general-purpose"
• model: "haiku". The two bundled scripts below already make every decision, so the subagent only runs one command and relays its output. A fast model is enough.
• description: "Gather repo-catchup commits"
• prompt: the brief below, with <FROM>/<TO> filled in from whatever --from/--to values apply. When a value is not set, omit that flag entirely from the command, so the script's own default applies.

Brief for the subagent

Run this exact command from the current directory and return its stdout verbatim, with
nothing else added:

node "${CLAUDE_SKILL_DIR}/scripts/gather-commits-cli.js" --from <FROM> --to <TO> | node "${CLAUDE_SKILL_DIR}/scripts/build-report-cli.js"

Omit a --from or --to token entirely rather than passing an empty value for it.

If the command exits non-zero, return its stderr text verbatim instead, prefixed with
"ERROR: ".

A git log over an arbitrary range has no size limit. This whole pipeline runs inside the subagent for that reason. Only its final, compact result crosses back into this conversation. A raw commit list never does.

After the subagent returns

Parse the subagent's reply.

• When the reply starts with ERROR: , relay the rest of that line to the user plainly and stop. Do not retry or guess a fallback range.
• Otherwise, parse it as JSON: { range: { from, to }, rows, summary }.

When rows is empty, reply with one plain sentence. State that nothing changed in the repository between range.from and range.to. Do not show a table.

Otherwise, compose the reply in two parts:

1. One-line executive summary, written by you from summary and range. State the number of rows, the number of distinct owners, and the date range. When summary.droppedBotCommits or summary.droppedMergeCommits is above zero, mention the dropped bot or merge commits parenthetically. Otherwise, omit that mention.
2. A table with columns Date | Owner | Ref | Description. One row per entry in rows, already sorted by owner then date:
   • Date: the first 10 characters of row.date (its YYYY-MM-DD portion).
   • Owner: row.owner verbatim.
   • Ref: `row.ref.label` as inline code. When row.ref.url is not null, render it as a markdown link instead. A null URL still renders as a plain code span, with no link.
   • Description: one short, plain sentence in your own words, built from row.subjects. Do not copy the commit message verbatim. When row.body is not null, add a why-clause from it, in your own words, never copied verbatim. Add as many clauses as the body supports. There is no fixed sentence-count cap. When row.body is null, write the subject-only sentence exactly as before.

The report goes into the chat reply only. Never write it to a file. Never publish it as an artifact.

Worked example

This fixture is synthetic. It is not this repository's own history. The repository's remote is GitHub, and gh is authenticated. A CODEOWNERS file at .github/CODEOWNERS names two teams:

/backend/ @acme/backend-team
/frontend/ @acme/frontend-team

--from v1.4.0 --to 2026-01-07 resolves. The v1.4.0 tag points at a commit dated 2026-01-01, so the ref form and the absolute form resolve together in one call. The subagent's pipeline returns:

{
  "range": { "from": "2026-01-01", "to": "2026-01-07" },
  "rows": [
    {
      "date": "2026-01-02T10:00:00+01:00",
      "owner": "@acme/backend-team",
      "ref": { "label": "#42", "url": "https://github.com/acme/widgets/pull/42" },
      "subjects": ["add password reset handler"],
      "hashes": ["148f3f4ae5c5e04b46f6500db4311d48ac26d703"],
      "body": "Users locked out of a stale session had no way back in on their own. This adds a self-service reset link."
    },
    {
      "date": "2026-01-03T11:00:00+01:00",
      "owner": "@acme/backend-team",
      "ref": { "label": "058fee1", "url": "https://github.com/acme/widgets/commit/058fee1654cd41717ae2b92af8a34092c7d52dc8" },
      "subjects": ["fix off-by-one in pagination offset"],
      "hashes": ["058fee1654cd41717ae2b92af8a34092c7d52dc8"],
      "body": null
    },
    {
      "date": "2026-01-04T12:00:00+01:00",
      "owner": "@acme/frontend-team",
      "ref": { "label": "#57", "url": "https://github.com/acme/widgets/pull/57" },
      "subjects": ["update nav bar layout"],
      "hashes": ["7dc2c10d4b9c86b03022d47c3bc40871cd8a025a"],
      "body": null
    },
    {
      "date": "2026-01-01T09:00:00+01:00",
      "owner": "Ada Lovelace",
      "ref": { "label": "e62c56c", "url": "https://github.com/acme/widgets/commit/e62c56c2d75d9776bac22580ed8d2c5af30bef7b" },
      "subjects": ["seed repo with CODEOWNERS"],
      "hashes": ["e62c56c2d75d9776bac22580ed8d2c5af30bef7b"],
      "body": null
    }
  ],
  "summary": { "totalCommits": 5, "droppedBotCommits": 1, "droppedMergeCommits": 0, "rowCount": 4 }
}

Before returning this result, the pipeline dropped one raw commit. A dependabot[bot] commit was bot-authored.

The password-reset commit and the pagination fix each touched a file under backend/. CODEOWNERS attributes both to @acme/backend-team, though two different people authored them. Merged pull request #42 covers the password-reset commit, so its row links to that pull request. That pull request also carries a body, so the row's Description adds a why-clause drawn from it. The pagination fix has no matching pull request and no commit body. Its row links to its bare commit instead and keeps the subject-only sentence.

The nav-bar commit touched a file under frontend/, so CODEOWNERS attributes it to @acme/frontend-team. Merged pull request #57 covers it too, so its row links to that pull request.

The CODEOWNERS-seeding commit touched only .github/CODEOWNERS itself. No rule in the file matches that path, so it falls back to its own author, Ada Lovelace.

The reply:

4 commits from 3 owners between 2026-01-01 and 2026-01-07 (1 bot commit omitted).

With no CODEOWNERS file at any of the three locations, every row falls back to its own author's name instead of a team. On a non-GitHub remote, or with gh missing or unauthenticated, every ref.url comes back null instead. The table then shows a plain code span, for example `9f8e7d6`, with no link.

A range with no commits, --from 2026-02-01 --to 2026-02-07 returning rows: [], gets a different reply, with no table:

Nothing changed in this repository between 2026-02-01 and 2026-02-07.