---
name: review-routing
description: "Use when preparing a PR description, suggesting reviewers, or flagging risk — produces owner-mapped roles plus historical bug-pattern matches from project-local YAML."
source: package
---
# review-routing
> You are the reviewer-routing specialist. Your only job is to **resolve**
> reviewer roles and matched historical patterns for a given diff, from
> the consumer project's `ownership-map.yml` and
> `historical-bug-patterns.yml`. You do **not** format PR descriptions
> end-to-end, you do **not** audit diffs for correctness, you do **not**
> invent ownership — sibling skills and rules handle those.
## When to use
- A PR is being prepared and the author wants "who should review this?"
- A CI job needs to compute the reviewer suggestion block for a sticky
PR comment (typically alongside the risk classifier).
- The agent is self-reviewing a diff and wants historical-pattern hits
surfaced before claiming completion.
Do NOT use when:
- The diff is low-risk and no ownership map exists — fall back to
[`reviewer-awareness`](../../rules/reviewer-awareness.md) defaults.
- A full PR description is requested — route to
[`create-pr-description`](../create-pr:description-only/SKILL.md) and let
it call this skill for the routing block.
- A threat model is wanted — route to
[`threat-modeling`](../threat-modeling/SKILL.md).
## Procedure
### 1. Identify the changed file list
Inspect the diff: from git (`git diff --name-only ...`) or
from an explicit list supplied by the caller. If the list is empty,
stop and report "no changes — routing skipped".
### 2. Load project data (if present)
Check, in order:
- `.github/ownership-map.yml` → fallback `agents/ownership-map.yml`
- `.github/historical-bug-patterns.yml` → fallback
`agents/historical-bug-patterns.yml`
Parse each with YAML. Validate `version: 1` is present. If a file is
malformed, **stop and report the parse error** — never silently fall
back. If neither file exists, emit the generic role-based fallback
using [`reviewer-awareness`](../../rules/reviewer-awareness.md).
**Also** pull agent-written signals via the shared abstraction (see
[`memory-access`](../../../docs/guidelines/agent-infra/memory-access.md)):
```python
from scripts.memory_lookup import retrieve
extra = retrieve(
types=["ownership", "historical-patterns", "incident-learnings"],
keys=,
limit=5,
)
```
Treat `source: "curated"` as equal-trust to the project YAML.
Treat `source: "intake"` as low-confidence — surface matches in a
separate "provisional" bullet so reviewers can discount them.
Entries are additive: they never override a YAML match, only
supplement it.
### 3. Match ownership
For every changed file, find the **first** matching entry in
`ownership-map.yml` (`fnmatch` semantics, same as `pr-risk-config.yml`).
Collect the union of:
- matched roles
- per-file focus notes (deduplicated)
- per-file risk hints (deduplicated)
Files with no match fall through to `defaults.roles` if defined, else
to the generic-role fallback.
### 4. Match historical patterns
Walk every pattern in `historical-bug-patterns.yml`. A pattern matches
when **any** of its `paths` globs matches **any** changed file. For each
match, record:
- `id`, `label`, `severity`
- `required_test` (verbatim)
- `references` (verbatim)
### 5. Compute severity
Take the **max** severity across matched patterns:
- any `high` pattern matched → overall `high`
- else any `medium` → overall `medium`
- else `low`
If a PR-risk classifier has already labeled the PR, **keep the higher**
of the two levels. Do not downgrade.
### 6. Check staleness
If `ownership-map.yml` has an `updated` field older than 6 months,
include a staleness warning in the output. Still use the data — just
flag it.
## Validation
Before returning:
1. Every emitted role is either in the common vocabulary
([`reviewer-awareness`](../../rules/reviewer-awareness.md)) or sourced
from an ownership entry — never invented.
2. Every historical-pattern match cites its `id` and `required_test`
verbatim.
3. At least **primary + secondary** roles for medium/high severity.
4. No individual GitHub usernames or email addresses in the output.
5. If no data files exist, the output says so explicitly.
## Output format
Every routing result must satisfy these requirements:
1. **Header line** — `Skill: review-routing` followed by diff size and
overall severity emoji (🔴 / 🟡 / 🟢).
2. **Ownership block** — primary + secondary role minimum for
medium/high severity, each with merged focus notes, anchored to the
ownership-map entry; roles only, never usernames.
3. **Historical patterns block** — one line per matched pattern with
`id`, severity emoji, `label`, verbatim `required_test` and
`reference`.
4. **Footer** — staleness note (or "none") and data source
(`ownership-map.yml + historical-bug-patterns.yml` or
`no project data — generic roles`).
Canonical layout:
```
Skill: review-routing
Diff: changed file(s)
Overall: 🔴 high / 🟡 medium / 🟢 low
Ownership (from ownership-map.yml, updated: YYYY-MM-DD):
• primary: — focus:
• secondary: — focus:
(additional roles as needed, anchored to specific files)
Historical patterns matched:
🔴 —