---
title: "Code Review Agents"
description: "Deploy agents that check PRs for regressions, missing tests, and weak patterns before human review."
url: https://www.callstack.com/services/code-review-agents
updated: 2026-11-09T15:58:18.592Z
---

# Code Review Agents

Deploy agents that check PRs for regressions, missing tests, and weak patterns before human review.

_[Agentic Delivery](/agentic-delivery) › [Custom Agents](/capabilities/custom-agents)_

**Every PR pre-reviewed before a human looks**

Review is where delivery queues. We build code review agents tuned to your standards that catch regressions, missing tests, and weak patterns first, so human reviewers spend attention where judgment matters.

## Custom Agents

- 3x Delivery acceleration · 80% Effort executed by agents
- Industry runs on our tooling · 50M+ OSS downloads / month
- 3.7× Lower task cost vs Opus 5.5
- Built on Agent Device. · T3 · Shopify · Tester Army · Agent Device
- React Foundation Founding Member · 300+ commits to React Native · Contributing since 2016
- 100+ Enterprise projects delivered
- ISO 27001 certified

## What you get: Review that scales with output.

- **Standards encoded** Your conventions, architecture rules, and review checklists turned into agent instructions.
- **Regression and test gaps** Changes flagged when behavior shifts or coverage is missing.
- **Pattern-level feedback** Weak abstractions and architectural shortcuts called out with suggested fixes.
- **Noise control** Tuned severity and suppression, so the agent earns trust instead of spamming nitpicks.
- **Repo-aware context** Reviews grounded in your codebase and history, not generic lint advice.
- **Metrics on review load** Time-to-merge and human review effort tracked before and after.

## Scope → Build → Scale: Build agents into repeatable workflows.

### Scope (1 WEEK)
We select a product workflow, define where agents act, and agree the controls and success measures.
- Workflow and owners defined
- Baseline and controls agreed
- Token budgets confirmed
### Build (1-12 MONTHS)
We connect context, agents, and verification to your tools, then run the workflow on your product backlog.
- Running on your product backlog
- Speed and quality measured
- Business impact validated
### Scale (AS NEEDED)
We document the workflow, transfer ownership, and extend it across teams and products based on results.
- Your team owns the workflow
- Expand based on results
- Full knowledge handover

## What shipping at AI speed looks like.

- [Building an Agentic SDLC for a Web Launch in Under One Month](/case-studies/building-an-agentic-sdlc-for-a-web-launch-in-under-one-month): 3x estimated delivery acceleration

**Free your seniors from nitpicks.** Agent review on every PR, human judgment where it counts. [Build custom agents](/contact)

> Their engineers proved to be a crucial part of our mobile app relaunch project.
>
> — Brian Aznar, Engineering Director, Major League Soccer

We’ll connect you with the right expert within 24 hours.

## Let’s find the right path for your product.

**Does this replace human review?**

No. It clears the mechanical layer - standards, regressions, test gaps - so the human pass is about design and intent, and takes a fraction of the time.
**How is this different from linters or off-the-shelf AI review?**

Linters check syntax rules; generic AI review knows nothing about your architecture. These agents are tuned to your conventions, your patterns, and your definition of done.
**Can we define custom rules?**

Yes - that is the core of the setup. Review checklists, architectural decisions, and team agreements become executable instructions, versioned in your repo.
**Where does our code go?**

Your choice: hosted models under enterprise terms, your cloud, or fully self-hosted inference for restricted environments.
**How do we measure the value?**

Time-to-merge, human review minutes per PR, and post-merge defect rates, compared against your pre-agent baseline.
**Who tunes the agent over time?**

Initially we do, based on accept and reject signals from your reviewers. After handover, tuning is a documented process your team owns.

## Open source

- [Agent Device](https://agent-device.dev/): CLI to control iOS and Android devices for AI agents
- [Agent React DevTools](https://github.com/callstackincubator/agent-react-devtools): Gives AI agents access to React DevTools
- [Agent Skills](https://github.com/callstackincubator/agent-skills): Callstack’s best practices on React Native performance optimization, upgrading, CI workflows, and brownfield migrations
- [React Native AI](https://github.com/callstackincubator/ai): On-device LLM execution in React Native with Vercel AI SDK compatibility
- [Skill Gym](https://incubator.callstack.com/skillgym/): Prove your agent skills work before you ship them