catchup

catchup — get back up to speed fast

Produce a concise, accurate summary of what changed in a scope the user gives you, so they can resume or review without reading every line.

Steps

1. Determine the scope

Figure out what to summarize from the user's request:

• a branch → diff vs its merge-base with the main branch
• a PR (number/URL) → use gh pr diff / gh pr view
• a commit range (abc..def) or "since <date>" → git log + git diff
• a file/dir → recent history for that path
• "what did I miss" with no scope → recent commits on the current branch since the user's last activity (ask if ambiguous)

2. Read the actual changes

Use git log --stat, git diff, and gh as needed. Read enough of the diff to understand intent, not just file names. Don't guess.

3. Summarize — tight and structured

Output to chat (no file unless asked):

• TL;DR — 1-2 sentences: the gist of what changed and why.
• Changes — grouped by area/feature, each with the why, not just the what.
• Risk / watch-out areas — anything subtle, breaking, migration-related, or worth a closer look in review.
• What's left / next — open TODOs, failing checks, unfinished threads (if detectable from commits, comments, or .plan docs).

4. Keep it honest

If something is unclear from the diff alone, say so rather than inventing rationale. Cite file:line or commit SHAs so the user can jump in.