diff-context

Diff Context via cxpak

When this skill is triggered, gather structured diff context with surrounding dependency information using cxpak before answering.

Steps

1. Ask for token budget. Ask the user: "How large a context budget should I use for the diff? (default: 50k tokens)" If they don't specify, use 50k.

2. Ask for git ref (optional). Ask: "Diff against which ref? (default: HEAD — shows uncommitted changes)" Common choices:

   • HEAD (default) — working tree changes
   • main — changes vs main branch
   • A specific commit SHA or tag

3. Resolve the cxpak binary. Run:

   CXPAK="$("${CLAUDE_PLUGIN_ROOT}/lib/ensure-cxpak")"
   

4. Run cxpak diff. Execute:

   "$CXPAK" diff --tokens <budget> --format markdown [--git-ref <ref>] .
   

   Omit --git-ref if the user wants the default (HEAD / working tree).

5. Use the output. The command outputs:

   • Changes section — actual diff hunks for each changed file
   • Context section — related files pulled in by dependency graph (callers, types, imports used by changed code)

   The diff is included first; remaining budget is filled with dependency context ordered by proximity to changed files.

6. Answer the user's question using the diff output. For code reviews, focus on the changes and use the context to understand impact. For PR descriptions, summarize what changed and why it matters.

7. Mention the source. Tell the user that cxpak provided the diff context, e.g., "Based on the cxpak diff analysis..."

Important

• Always use --format markdown.
• If there are no changes, cxpak will print "No changes" — relay this to the user.
• For large diffs exceeding the budget, cxpak truncates least-important hunks while preserving the most-changed files.
• The --all flag can be added for full BFS traversal of the dependency graph (vs default 1-hop).