review-router

name	review-router
description	Routes PR review by diff — delegates to backend/frontend specialist.

Review Router

Classify the changeset and route to the correct specialist reviewer(s). Run this logic before any review work begins.

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Step 1 — Classify the Diff

Run the following command to get the list of changed files:

git diff main...HEAD --name-only 2>/dev/null || git diff HEAD~1 --name-only

If reviewing a specific ref or PR branch, adapt the command accordingly. For an override, check whether the user passed an explicit argument (/review backend, /review frontend, /review both) — if so, skip classification and go directly to Step 2.

Classification Heuristics

Score each changed file against the two path sets below. A file matches backend or frontend (or both) based on its extension and directory.

Backend signals

Pattern	Examples
Server-side extensions	*.go, *.py, *.rb, *.php, *.java, *.kt, *.rs, *.ex, *.exs, *.cs
Server directories	app/Http/, app/Models/, app/Services/, app/Repositories/, app/Jobs/, app/Events/, app/Listeners/, app/Console/
Database	database/migrations/, database/seeders/, db/migrate/, alembic/, prisma/migrations/
API/config	routes/api.*, config/, src/routes/, src/controllers/, src/services/, src/repositories/
Infrastructure	docker-compose.yml, Dockerfile, *.tf, .env.example

Frontend signals

Pattern	Examples
Component extensions	*.tsx, *.jsx, *.vue, *.svelte
Style files	*.css, *.scss, *.sass, *.less, *.module.css
Frontend directories	src/components/, src/pages/, src/views/, src/app/ (Next.js), src/hooks/, src/context/, src/store/, resources/js/, resources/css/, resources/views/
Assets	public/, assets/, static/
Frontend config	vite.config.*, next.config.*, nuxt.config.*, tailwind.config.*

Shared / ambiguous files

Files like *.ts (non-React), package.json, tsconfig.json, or *.json alone do not determine the type. Count only if paired with other signals on the same side.

Classification Result

Condition	Result
Only backend signals	BACKEND
Only frontend signals	FRONTEND
Both signals present	BOTH
No clear signal	BOTH (safer default — include all reviewers)

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Step 2 — Route

Result: BACKEND

Proceed as backend-reviewer. Apply all categories from agents/backend-reviewer.md without invoking a separate agent. State at the start of the review:

Review type: Backend (classified from diff — N backend files, 0 frontend files)

Result: FRONTEND

Proceed as frontend-reviewer. Apply all categories from agents/frontend-reviewer.md without invoking a separate agent. State at the start of the review:

Review type: Frontend (classified from diff — 0 backend files, N frontend files)

Result: BOTH

Do not attempt a full review alone. Output the following routing message and stop:

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Review type: Full-stack (N backend files + M frontend files detected)

This PR has both backend and frontend changes. For the most thorough review, invoke the two specialist agents in parallel by sending both prompts in a single message:

Prompt A → backend-reviewer: "Review the backend changes in this PR. Focus on: API contracts, database transactions, N+1 queries, auth/authz, background jobs, race conditions, SOLID, and security."

Prompt B → frontend-reviewer: "Review the frontend changes in this PR. Focus on: component design, re-renders, accessibility, bundle size, state management, XSS, loading/error states, and type safety."

Send both prompts simultaneously — they are independent and can run in parallel.

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Manual Override

Users can bypass classification by passing an explicit argument:

Command	Behavior
/review backend	Skip classification → route as BACKEND
/review frontend	Skip classification → route as FRONTEND
/review both	Skip classification → output routing message for BOTH

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Project-Specific Path Overrides

Projects with non-standard directory structures can define custom path mappings in docs/development/code-standards.md or CLAUDE.md under a ## Review Router section:

review-router:
  backend-paths:
    - "server/"
    - "lambda/"
  frontend-paths:
    - "web/src/"
    - "mobile/src/"

When this block is present, use it instead of the default heuristics above.