diff-intake

name: diff-intake description: > Reads a PR or branch diff and produces a structured YAML change brief for downstream analytics instrumentation skills. Use this as the first step whenever a user shares a PR link, branch comparison, or raw diff and wants to understand what changed, what needs tracking, or how to instrument a feature. Trigger on phrases like "review this PR", "what changed in this branch", "help me instrument this diff", "check analytics coverage for this change", or any request to start the analytics review workflow.

diff-intake

Follow this skill step by step. You are step 1 of the analytics instrumentation workflow. Produce a compact YAML change brief that downstream skills (discover-event-surfaces, instrument-events) will consume. Keep the output machine-readable and precise — no prose around the YAML block.

Step 1: Gather changed files and categorize

Fetch the list of changed files from the source, then categorize each one.

Fetching changes

• PR URL gh pr view <number-or-url> gh pr view <pr-number> --json files --jq '.files[] | "\(.path)\t+\(.additions) -\(.deletions)\t"'
• Branch comparison git log <main|master>..<branch> git diff --stat <main|master>..<branch>
• Ambiguous mention (PR number, branch name): infer the right form and fetch without asking unless auth fails.

Categorize files

Assign each file to a category based on its path:

• Core Logic: application source (e.g. src/auth/login.py, database/models.ts)
• Generated: anything with generated in its path
• Testing: test files
• Config / Dependencies: package.json, docker-compose.yml, etc.
• Documentation: READMEs, docs/
• Noise: lock-files, .svg, auto-generated migrations

For each file, record: path, category, change type (Added / Modified / Deleted), and analytics likelihood (1–5).

Step 2: Build the file summary map

Read every single Core Logic file and create the file summary map. Only process and include Core Logic files.

Fetching detailed diffs

• PR gh pr view <number-or-url> --json baseRefOid,headRefOid Using the response, get a detailed diff git diff <baseRefOid>...<headRefOid> -- <file1> <file2> <file_n>
• Branch comparison git diff main..feature/foo -- <file1> <file2> <file_n>

For each file, record

• summary — 2-line summary of what changed
• stack — frontend, backend, or shared

Also derive user-facing changes and touched surfaces

While reading the diff and the changed files, also produce the higher-level signals that downstream event discovery needs:

• user_facing_changes — a flat list of concrete behavior changes that matter to a user, PM, or analyst. Each item should describe what a user can now do, see, or experience differently. Omit purely internal refactors.
• surfaces.components — the UI components, routes, pages, handlers, or other interaction surfaces directly involved in those user-facing changes. Prefer likely instrumentation points over low-level helpers.

For each surface, record:

• name — component, route, page, hook, or surface name
• file — repo-relative path
• change — added, modified, or deleted

If the change is backend-only or has no clear interactive surface, omit surfaces.components rather than inventing one.

Step 3: Classify the overall change

Infer the change type and analytics scope:

analytics_scope = highest implication present:

• none — only no-impact types
• low — only perf/refactor
• medium — fix
• high — any feature or capability addition

If analytics_scope is none, emit the brief and note that downstream skills are not needed.

Step 4: Emit the YAML brief

Output only the YAML block — no prose before or after. Follow the format exactly. List each file individually in file_summary_map (no globs).

change_brief:
  classification:
    primary: feat           # dominant conventional commit type
    types: [feat, fix]      # all types detected
    analytics_scope: high   # none | low | medium | high
    stack: frontend         # frontend | backend | fullstack
  summary: "One sentence describing the overall change"
  user_facing_changes:
    - "Users can now upload an avatar with drag-and-drop and preview it before saving."
  surfaces:
    components:
      - name: "AvatarUpload"
        file: "src/components/AvatarUpload.tsx"
        change: modified
  file_summary_map:         # each entry includes a layer field
    - file: "src/components/AvatarUpload.tsx"
      summary: "New component for avatar upload with drag-and-drop and preview"
      layer: frontend       # frontend | backend | shared
    - file: "src/api/upload.ts"
      summary: "Upload endpoint handler, validates file type and persists to S3"
      layer: backend