Agentic Infrastructure

Custom Agents

Custom Agents

Put agents on recurring engineering work.

Teams get more from AI when agents take on repeatable engineering work. We set up internal agents and workflows so work can run in parallel and continue after a developer session ends.

Build custom agents
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Custom Agents

Why build agents with Callstack

Turn repeatable work into agents.

We build internal agents around your standards, repos, and delivery systems so recurring work keeps moving after a developer session ends. Teams reduce manual review, testing, docs, and workflow steps.

Keep work moving in parallel.

Agents continue repeatable engineering work beyond a single developer session.

Cut the busywork around delivery.

Review, testing, documentation, and workflow steps need less manual effort.

Turn team habits into tools.

Internal agents capture standards and workflows that would otherwise stay informal.

Grow output without hiring linearly.

Teams can handle more work without matching every gain to headcount.

Services

Automate the work around delivery.

Use Cases

Code Review Agents

Check PRs for regressions, missing tests, weak patterns, and team standards before human review.

Upgrade Agents

Run framework, dependency, and React Native upgrade work with repeatable checks and migration steps.

Maintenance Agents

Handle routine cleanup, dependency updates, deprecated APIs, and repo hygiene before they block delivery.

Documentation Agents

Keep technical docs, changelogs, release notes, and implementation notes aligned with code changes.

CI/CD Automation Agents

Automate build checks, pipeline fixes, test reruns, release gates, and rollout steps across your delivery workflow.

Internal Tool Agents

Connect agents to tickets, repos, CI, Slack, Linear/Jira, and internal systems with scoped access and clear rules.

Custom Agents

Build agents for your delivery workflow.

Show us your most repetitive workflows. We will build custom agents that handle the heavy lifting while your team focuses on high-impact work.

Build custom agents

Design → Build → Extend

Build agents into repeatable workflows.

Design

We map the mobile delivery stack, controls, and cost. You get the plan before migration starts.

See hosted vs self-hosted economics
Find the gaps in the delivery stack
1 WEEK

Build

We deploy QA, CI/CD, OTA, and telemetry. The mobile delivery stack runs in your environment from day one.

QA agent, OTA, and CI/CD included
Telemetry and release signals included
2-4 WEEKS

Extend

Your team owns the stack long term. We stay on to extend it as delivery needs grow.

Extend the stack beyond the first rollout
Add new agents as needs change
AS NEEDED

Manifesto

When the way software is built changes, 
we help companies adopt it.

AI-native teams run on a system, not only on tools. Agents move the work forward. Experts make the calls that shape the outcome.

Learn Callstack Delivery Model

Case studies

What shipping at AI speed looks like

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10 years of React Native → Now in your AI stack

Build agents for your delivery workflow.

Show us your most repetitive workflows. We will build custom agents that handle the heavy lifting while your team focuses on high-impact work.

Build custom agents

Why teams bet on Callstack

From billion-user apps to React Native core, this is why teams choose Callstack when they need to move fast and get it right.

Rocket ascending into a blue night sky with digital binary code forming its smoke trail.

10 years in React Native. Now shaping agentic engineering.

For a decade, we have helped define how teams ship with React Native. Now we are helping shape how they work with agents.

Founded in 2016 ·Backed by Viking Global Investors

React Foundation members. Core Contributors.

We are founding members of React Foundation and Core Contributors to React Native. You get direct access to people close to the decisions shaping the frameworks you use.

Open source since 2016. Our code runs in your app.

We contribute to React Native and maintain libraries across its ecosystem. Our code runs in apps used by millions of people every day.

Open Source Projects

39M+

Downloads / month

67K+

GitHub stars

300+

React Native commits

100+ Enterprise clients with 7B+ users.

We work with teams shipping at real scale. You get a partner used to high-stakes products, not learning on your roadmap.

Agent Conf. The conference for the Agentic era.

The conference we built for the shift from writing code to orchestrating agents.

Agent Conf
Gradient background blending white, light blue, and purple shades with smooth transitions.Man wearing glasses and a Stanford sweatshirt speaking into a microphone during a presentation.

We are Codex Ambassadors.

We run meetups, workshops, and hands-on 
sessions that help teams learn Codex 
and apply it in real work.

Check Events
Rocket ascending into a blue night sky with digital binary code forming its smoke trail.

10 years in React Native. Now shaping agentic engineering.

For a decade, we have helped define how teams ship with React Native. Now we are helping shape how they work with agents.

Founded in 2016 ·Backed by Viking Global Investors

React Foundation members. Core Contributors.

We are founding members of React Foundation and Core Contributors to React Native. You get direct access to people close to the decisions shaping the frameworks you use.

Open source since 2016. Our code runs in your app.

We contribute to React Native and maintain libraries across its ecosystem. Our code runs in apps used by millions of people every day.

Open Source Projects

39M+

Downloads / month

67K+

GitHub stars

300+

React Native commits

100+ Enterprise clients with 7B+ users.

We work with teams shipping at real scale. You get a partner used to high-stakes products, not learning on your roadmap.

Agent Conf. The conference for the Agentic era.

The conference we built for the shift from writing code to orchestrating agents.

Agent Conf
Gradient background blending white, light blue, and purple shades with smooth transitions.Man wearing glasses and a Stanford sweatshirt speaking into a microphone during a presentation.

We are Codex Ambassadors.

We run meetups, workshops, and hands-on 
sessions that help teams learn Codex 
and apply it in real work.

Check Events

Open Source

Want to build it on your own?

We open-source the tools behind our delivery model.
Use them, fork them, or let us run them for you.

Check All Tools
Explore AI Infrastructure
Agent Device

CLI to control iOS and Android devices for AI agents

188238
downloads / month
Agent React DevTools

Gives AI agents access to React DevTools

222
stars
Agent Skills

Callstack’s best practices on React Native performance optimization, upgrading, CI workflows, and brownfield migrations

1374
stars
React Native AI

On-device LLM execution in React Native with Vercel AI SDK compatibility

22123
downloads / month
Skill Gym

Prove your agent skills work before you ship them

1500
downloads / month
React Native Evals

A benchmark suite for evaluating how coding models solve real React Native tasks

91
stars

Insights

Worth your time, by engineers.

Explore Insights
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Jun 19
·
Article

Building Mobile QA Agents With Vercel Eve

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.
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Jun 10
·
Article

5 Lessons From Vibe Coding Before You Ship with AI

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.
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May 21
·
Article

Agencies or Swarms? What Small Model Cooperation Means for AI Engineering

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.
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Apr 1
·
Article

Agents Commander: A Lightweight Interface for Multi-Agent CLI Workflows

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.
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Feb 4
·
Article

Giving AI The Keys to Your App: Agents Controlling UI State

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.
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Jan 22
·
Article

Flows AI: Your Library for Building AI Workflows on Top of Vercel AI SDK

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.
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Jan 17
·
Article

Building AI Agent Workflows With Vercel’s AI SDK: A Practical Guide

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.
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Nov 25
·
Podcast

Building a Custom AI Assistant for Your Business

Learn what it takes to build a custom AI-powered chatbot for your company, including the challenges, solutions, performance, and security considerations.
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September 17, 2026
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Event

Agent Conf

Join 500+ engineers in Warsaw Sept 17-18 2026 for Agent Conf. Learn agentic development, orchestration, and AI-driven workflows.
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September 2, 2025
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Event

AI for the Other Parts of Your Technical Job

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.