--- 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: 2026-11-06T10:08:13.516Z --- # 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. [Build custom agents](#contact) · [How it works](#what-you-get) ## 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. **Free your seniors from nitpicks.** Agent review on every PR, human judgment where it counts. [Build custom agents](#contact) ## 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. Still have questions? Whether you’re planning new work or unblocking an existing product, we’ll help you choose the right path forward. **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. [Book consultation](#contact) ## 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 Insights ## Worth your time, by engineers. [Explore Insights](https://www.callstack.com/insights) - [Building Vault: A Dual-Screen Terminal for Self-Hosted AI Agents](https://www.callstack.com/blog/building-vault-a-dual-screen-terminal-for-self-hosted-ai-agents) (Jul 22 · Article): Vault is a dual-screen handheld terminal for controlling AI agents and locally hosted LLMs from a purpose-built device. This article explains how the prototype combines an ESP32-S3, OLED, and e-paper display with an OpenClaw agent and gpt-oss-120b served on a LAN host through TensorRT-LLM. It covers the interface architecture that separates live task status from completed output, the Python broker that keeps inference off the device, the hardware failures that shaped the build, and the security limits of remote command execution. - [Building Mobile QA Agents With Vercel Eve](https://www.callstack.com/blog/building-reviewable-mobile-qa-agents-with-vercel-eve) (Jun 19 · Article): This article walks through migrating a mobile QA agent from a single AI SDK tool loop to Vercel Eve. It shows how Eve’s filesystem-first structure, typed tools, and durable sessions make agent behavior easier to inspect, review, and maintain inside EAS Workflows. - [5 Lessons From Vibe Coding Before You Ship with AI](https://www.callstack.com/blog/5-lessons-from-vibe-coding-before-you-ship-with-ai) (Jun 10 · Article): AI agents can turn an app idea into working code in hours. They can also overbuild simple features, miss your architecture, and quietly run up cost. In this article, Hristo Totov breaks down five practical lessons for using AI agents with better prompts, better feedback loops, and better engineering judgment. - [Agencies or Swarms? What Small Model Cooperation Means for AI Engineering](https://www.callstack.com/blog/agencies-or-swarms-what-small-model-cooperation-means-for-ai-engineering) (May 21 · Article): Agentic systems may not depend only on larger models. This article examines how swarms of smaller models behave under load and what that means for distributed inference, concurrency, and infrastructure design. - [Agents Commander: A Lightweight Interface for Multi-Agent CLI Workflows](https://www.callstack.com/blog/agents-commander-a-lightweight-interface-for-multi-agent-cli-workflows) (Apr 1 · Article): Agents Commander introduces a practical way to manage multi-agent environments directly in the CLI. With a minimal communication protocol, it enables agents to collaborate without complex infrastructure or rigid APIs. - [Giving AI The Keys to Your App: Agents Controlling UI State](https://www.callstack.com/blog/giving-ai-the-keys-to-your-app-agents-controlling-ui-state) (Feb 4 · Article): This project shows how to let AI agents control UI state in React apps using Jotai and Flows-AI. By moving logic outside components, agents can autonomously update the UI based on prompts and context to enable smarter, automated workflows. - [Flows AI: Your Library for Building AI Workflows on Top of Vercel AI SDK](https://www.callstack.com/blog/flows-ai-your-library-for-building-ai-workflows-on-top-of-vercel-ai-sdk) (Jan 22 · Article): Flows AI is a lightweight library for building AI agent workflows on top of Vercel AI SDK. It provides a simple, flexible way to orchestrate agents as async functions, with built-in control flow agents for parallel execution and composing flows. - [Building AI Agent Workflows With Vercel’s AI SDK: A Practical Guide](https://www.callstack.com/blog/building-ai-agent-workflows-with-vercels-ai-sdk-a-practical-guide) (Jan 17 · Article): Building AI agent workflows doesn't have to be complex. This practical guide walks through how to use Vercel's AI SDK to create chained, routed, parallel, and evaluator-optimizer workflows step-by-step, with code examples you can try yourself. - [MCP and Supervisor Agents in eBay's Monitoring Workflow With Leonel Candido da Silva](https://www.callstack.com/podcasts/mcp-and-supervisor-agents-in-ebays-monitoring-workflow-with-leonel-candido-da-silva) (Oct 13 · Podcast): Leonel Candido da Silva explains eBay's agentic monitoring workflow: specialized agents, MCP, PagerDuty reports, and plans to learn from past incidents. - [State Machines for AI Agents With David Khourshid](https://www.callstack.com/podcasts/state-machines-for-ai-agents-with-david-khourshid) (Oct 12 · Podcast): David Khourshid explains state machines for AI agents, human approval steps, tracing, and handling invalid model outputs in agent workflows. - [Inside Cursor, Colossus, and Grok Bot With Nick Miller](https://www.callstack.com/podcasts/inside-cursor-colossus-and-grok-bot-with-nick-miller) (Oct 12 · Podcast): Nick Miller explains Cursor's move to SpaceXAI, how Colossus changed model training, and the browser experience behind Grok Bot. - [Building a Custom AI Assistant for Your Business](https://www.callstack.com/podcasts/building-a-custom-ai-assistant-for-your-business) (Nov 25 · Podcast): Learn what it takes to build a custom AI-powered chatbot for your company, including the challenges, solutions, performance, and security considerations. - [From Design to Shipped: A Modern App Development Meetup](https://www.callstack.com/events/from-design-to-shipped-a-modern-app-development-meetup) (Oct 22 · Meetup): Join Callstack, JetBrains, and Expo in Amsterdam on October 22 for talks on AI agents, UI development, and verification across web and mobile. - [Graph Agentic Coding Extends AI Workflows](https://www.callstack.com/events/how-graph-agentic-coding-extends-ai-workflows) (Aug 27 · Live Stream): How connected state, retrieval, memory, and verification carry coding agents across complex, multi-step workflows. Kewin Wereszczyński and Lech Kalinowski discuss the structures that let agents plan, retrieve context, use tools, and keep working across longer tasks. - [Beyond Coding Agents: Making ADLC Work Across Platforms](https://www.callstack.com/events/beyond-coding-agents-making-adlc-work-across-platforms) (Nov 16 · Talk): Mike Grabowski will explain how to close the full agentic development lifecycle across mobile, web, and native platforms. - [How We Built a React Native News Agent With Eve](https://www.callstack.com/events/build-a-react-native-news-agent-with-eve) (Jul 30 · Live Stream): See how we built and deployed an Eve agent that tracks React and React Native repositories, filters commit noise, and publishes daily Slack updates. - [Agent Conf](https://www.callstack.com/events/agent-conf) (Sep 17 · Conference): Join 500+ engineers in Warsaw Sept 17-18 2026 for Agent Conf. Learn agentic development, orchestration, and AI-driven workflows. - [AI for the Other Parts of Your Technical Job](https://www.callstack.com/events/ai-for-the-other-parts-of-your-technical-job) (Sep 2 · Talk): Stop fitting your workflow into off-the-rack tools. Learn to build your own AI-powered solutions, including a custom slide generator and a collaborative developer notebook.