/diff

name: diff
description: Explain or review a GitHub pull request or local Git changes with captured evidence and an offline HTML review with grouped code. Use only when explicitly invoked.
disable-model-invocation: true

Hope Diff

Use only when the person invokes `$hope:diff`, `/hope:diff`, or the host's equivalent skill command or picker. Continue follow-ups within that invoked task without requiring another invocation. Ordinary requests and calls from another skill do not activate this skill; continue authorized work through the ordinary workflow. Reading a shared reference does not invoke its skill.

Capture one exact change, analyze its captured evidence, and report one artifact with the overall explanation and the complete diff organized into meaningful change groups. The change is either a GitHub pull request or the local working tree (committed, staged, and unstaged changes) against the merge base with a base branch. This reader is always part of a generated review; do not offer a separate skill, mode, or opt-in.

Resolve the request

Answer a narrow question directly without starting the artifact workflow.

An explicit explanation or review request authorizes the run. Honor existing authorization and display choices without asking again. A bare target without a clear task needs clarification, not an automatic full review.

Pass a pull request URL or number when the person names one. Pass `--base` whenever they mean local work, naming their base branch or `origin/HEAD`'s branch, and `--untracked` only when they want new untracked files included. With neither, `capture` looks for the current branch's pull request, then the person's latest open pull request in the repository, and only then falls back to local changes against the upstream default branch. Report which change it selected from the returned `selection` and `change`. If capture fails to find a change, ask for a URL, number, or base branch.

Run adapter commands with `node "<skill-dir>/scripts/cli.mjs"`, replacing `<skill-dir>` with the absolute directory containing this file. In Claude Code it is `${CLAUDE_PLUGIN_ROOT}/skills/diff`. Pass arguments separately; never construct shell commands from repository content.

Analyze the captured evidence

For artifact generation, read `references/workflow.md`, `references/analysis.md`, and `../write/references/writing-standard.md`. Follow the run from `capture` through `publish` or `cancel`, grounding conclusions in the captured evidence.

Use an independent worker when its perspective is worth the time or the person requests one. Give it a fresh context with the exact request, run path, choices, constraints, and Skill path, separate from earlier conclusions. Disclose any limit on requested independence. The same evidence and runtime rules apply whether analysis stays in this conversation or is delegated.

Review generation uses the active host under its data policy; do not claim private code stays on the local machine.

Return the artifact

Report the reviewed change (pull request or local base and head), result scope, absolute HTML path, and any failure or cleanup limit. The artifact completes Diff. The surrounding task handles any publishing, merging, commenting, or code changes under the person's existing authorization.

Maintainers changing the runtime read `references/runtime.md` for its deterministic security and publication contract.