trailofbits/pr-improver

PR Improver

Improve the current branch by running /code-improver:improve — a dynamic workflow that loops a PR reviewer and a fixer subagent over the branch's changes until a review reports zero critical/major findings. The loop, its ledger, and its guards live in the workflow; this skill derives the scope from the branch diff and relays the outcome.

Starting the loop

The user provided: $ARGUMENTS (if empty, take base branch and preferences from the conversation).

1. Resolve the branch and its change surface

1. Repo root: git rev-parse --show-toplevel. Fail loudly outside a repository.
2. Base: the argument if given, else the repository's default branch (git symbolic-ref refs/remotes/origin/HEAD → its short name, falling back to main). Refuse to run when the current branch IS the base — there is no diff to improve.
3. Changed files: git diff --name-only <base>...HEAD. If empty, say so and stop.
4. Scope: the changed files' directories, widened — per-file globs are too tight (PR fixes legitimately add tests next to changed code). Map each changed file to its repo-relative directory glob <dir>/** (** at the repo root only if files at the root changed), then deduplicate and drop globs covered by another.

2. Resolve the loop script

The loop is the dynamic workflow workflows/improve.js in this plugin. Launch it by path: scriptPath takes a resolved absolute path, and the Workflow tool's name resolves built-in and project workflows, so a marketplace-installed one may not answer to code-improver:improve. Try in order, first hit wins — the home directories come before . so an installed copy beats a checkout of this marketplace:

1. Bash: ls -d -- "${CLAUDE_PLUGIN_ROOT}/workflows/improve.js"
2. Bash: ls -d -- "${CODEX_PLUGIN_ROOT}/workflows/improve.js" (if that variable is set instead)
3. Bash: find ~/.claude ~/.codex . -maxdepth 7 -path '*/code-improver/workflows/improve.js' -print -quit 2>/dev/null

Use the path exactly as printed. Its plugin directory — the path with /workflows/improve.js removed — is pluginRoot. If all three come back empty, try {name: "code-improver:improve"} once; if that is unavailable too, stop and say the loop could not be located. Do not assemble a path by hand and do not improvise the loop.

3. Invoke the workflow

Run it with the Workflow tool, {scriptPath: "<the path from step 2>", args: {...}}:

{
  "target": "<repo root>",
  "reviewer": {
    "kind": "skill",
    "name": "pr-review-toolkit:review-pr",
    "notes": "Review the working tree's changes against <base> as a pull request: correctness, tests, error handling, and the review dimensions the skill prescribes."
  },
  "scope": ["<derived-dir-glob>/**"],
  "pluginRoot": "<the plugin directory from step 2>",
  "maxRounds": 5
}

• reviewer — the default above requires the pr-review-toolkit plugin. When the user names a different PR reviewer (skill or agent), use it, with kind set accordingly.
• maxRounds only if the user asked for a different cap.
• pluginRoot lets the run find its metrics collector; omit the key only if step 2 fell through to the workflow name — the workflow then searches for itself.
• finalize defaults are right for PRs: no version bump unless the branch sits inside a plugin, narration strip and docs pass on.
• decision only on continuation (below).

The loop's baseline snapshot is the tree at loop start — its scope guard protects the branch's uncommitted work; the PR's own commits are what the reviewer reviews.

The workflow runs in the background and needs no babysitting: it reviews, fixes, re-reviews, checks scope after every fix round, and can only complete on a clean review. It never commits; all changes stay in the working tree.

If the Workflow tool is unavailable or denied, stop and say so. Do not improvise the loop inline with direct edits — the ledger, scope guard, and escalation guarantees live in the workflow, and an inline imitation has none of them.

If the result is halted: "reviewer-unavailable", relay it and stop. The reviewer is not installed in this session; tell the user which plugin provides it (the default needs pr-review-toolkit) and re-run after installing. Do not review the branch yourself.

Do not end your turn while the loop is running. The Workflow tool returns a task id immediately; the result comes later. In an interactive session the completion notification re-invokes you — wait for it. In a non-interactive run (scripted, CI, eval) there is no later turn: stopping abandons the loop mid-round, so after launching, poll the task (TaskOutput with the returned task id, or sleep-and-recheck) until it completes, then relay the result. A session that answers "the loop is running, I'll report later" has lost the run.

Relaying the result

The workflow returns a structured result. Report it honestly — the distinctions matter:

• converged: true — the last action was a review with zero critical/major findings. Report rounds used, remaining minor findings (open_minor_count), and the artifact paths (ledger_path, metrics).
• capped: true — the fix budget ran out and the FINAL review still found blocking issues. Say plainly: capped, NOT converged, and list open_blocking. Do not present this as success.
• escalation — the loop detected it was not converging (recurring findings, non-decreasing counts, or a fix relocating a problem). Relay the escalation message and finding ids to the user: this needs a design decision, not more rounds.
• halted — a guard fired (scope violation, unregistered new files, a dead or unavailable reviewer, or a finalize pass whose own edits failed the check that follows it). Relay the paths in violations/new_untracked_files, the sites in finalize_regressions, and the notes.
• notes always travel with the result — surface them; they include loud warnings such as "a git repository was initialized".

Continuing after an escalation

The loop stops on escalation by design. When the user decides, start a fresh run with the same args plus:

{ "decision": "<the user's ruling, verbatim>" }

The new run reloads the on-disk ledger, so every finding, rejection, and verdict carries over — rounds restart, re-derivation does not.

To stop a running loop, stop the workflow task (TaskStop); the ledger on disk is current to the last round and a re-run resumes from it.

When NOT to use

• One-time review: run the PR-review skill directly; the loop's value is iteration
• A skill: use the skill-improver entry — it wires the right reviewer
• Unpushed exploratory work: review-and-fix loops harden a diff; while the shape is fluid, manual iteration gives more control