Kosuke vs Claude Code vs Background Agents

Hand off the boring tickets. Keep the hard engineering.

Kosuke runs your codebase in a live sandbox so PMs, designers, and marketing ship small tickets themselves. No blind diffs from background agents, just tested work you can actually merge.

Watch Video

Everyengineerknowsthefeeling.Youopenyoursprintboardandmostofitisn'tengineering.Abuttoncolor.Atooltiprewrite.Onemorefieldonthesignupform.Theticketsthateatyourdaybeforeyougettoanythingthatmatters.Kosuketakesthemoffyourplate,inalivesandboxofyourtechstack.Youreview.Youapprove.Youmerge.Backtorealengineering.

of tickets you shouldn't be touching

Not another background agent.

Hand off the bullshit tickets

Copy tweaks, feature flags, new form fields, marketing changes. The small stuff that breaks your flow every time but blocks everyone else until it ships. Let your team take it from ticket to PR. You review the diff when it lands.

A preview, not a promise

Every change spins up a live preview wired to your code, your DB, your env. Your PM sees it, tests it, iterates until it's right, then opens the PR. You review work that's already been QA'd, not a blind diff from a headless agent.

Your architecture, respected

Kosuke picks up your patterns from the repo itself. Your structure, your components, and the house rules you've documented for your team. Every change feels like your team wrote it. You're reviewing changes, not reformatting them.

Configure once. Ship forever.

Connect your repo, spin up the sandbox, set your conventions once. Every ticket after that runs inside those boundaries. Your team shipping, you reviewing only what matters.

Configure× 1

01Import repo

02Define sandbox

03Set conventions

Done

Ship∞

Update pricing copymaria/pm

Add FAQ entrysam/marketing

Fix nav hoveralex/design

Update pricing copymaria/pm

Add FAQ entrysam/marketing

Fix nav hoveralex/design

Describe

Preview

Iterate

Pull request

Merge

Engineering effort over time

CONFIG

SHIP ∞

Why not just use Claude Code?

Because your PM shouldn't need to configure a local development environment to fix a typo.

$ git clone git@github.com:acme/app.git

Permission denied (publickey).

$ brew install docker postgres node@20

Installing dependencies… (4 min)

$ docker compose up

Error: port 5432 already in use

$ cp .env.example .env.local

Missing: STRIPE_KEY, GHOST_KEY, SENTRY_DSN…

$ bun run db:migrate

Schema drift detected.

$ claude code

Ready.

previews-1248.kosuke.ai

What Kosuke requires

A browser.

That's it.

No terminal. No git. No Docker. No env files. Describe what you want, preview it live, ship.

Why not just use Linear Agents or Cursor Agents?

Because a PR without a preview is useless for non-technical people.

Background agents

Stuck on review

PROJ-247Todo

Build user dashboard module

featureP1dashboard

@agent

2h ago

agent.cliWorking

>Build user dashboard module

Read(dashboard/page.tsx)

Grep("metrics = [")

Edit(dashboard/page.tsx)

Write(kpi-card.tsx)

Bash(bun run lint)

PR #1248Open

app/dashboard/page.tsx

+ import { KpiCard }

+ import { useMetrics }

- const data = []

+ const metrics = {

+ revenue, users, uptime

+ }

8 files · +183 −42

A diff isn't a preview. The PM can't tell if it's right, and the engineer becomes the bottleneck.

Kosuke

Shipped in minutes

promptBy PM

Build a dashboard module for the user: add revenue, active users, and uptime KPI cards with real-time data. Each card should show the current value, a trend indicator, and a secondary label.

preview-1248Live

9:41

Dashboard

Revenue

$12.4k

+18% vs last month

Active users

2,847

142 online now

Uptime

99.9%

Last 30 days

Your app, live preview

Scan to open the live preview

Point your camera to preview

PR #1248Ready

Previewed by the PM

Tested in preview

Approved by design

+247 −84ready to merge

Engineers review code that's already been tested. Just a clean PR, ready to merge.

Works with your favorite stack.

Frontend

10 stacks

Next.js

React

Vue

Nuxt

Svelte

SvelteKit

Angular

Astro

Remix

SolidJS

Backend

14 stacks

Node.js

Python

Express

Hono

Nest.js

Django

Flask

FastAPI

Ruby on Rails

Laravel

Spring Boot

.NET

Rust

Data

6 stacks

PostgreSQL

Supabase

Redis

MySQL

MongoDB

SQLite

Not seeing your stack? Contact us.

Ship demos, not meetings.

When every branch is a live environment, your whole team moves faster.

Demo without engineers

Every sandbox is a shareable link. Product shows customers, Sales demos to prospects, CS walks clients through workflows. No engineer required.

Non-technical teammates ship

Hand off copy changes and config tweaks to PMs. You focus on architecture.

QA without sync

Every PR is a live preview. No more "deploy to staging" requests.

Enterprise-ready

In Progress

Built for compliance.

Designed for SOC 2, GDPR, and HIPAA standards.

Dev Mode

The first Cloud IDE built for the agents era

No more worktrees. No more port conflicts. Run up to five agents in parallel, each in its own live cloud sandbox. Share a preview link, review the code, and merge when it's ready.

agent-1

agent-2

agent-3

agent-4

agent-5

Every change, tested on camera

Agents don't just write code. They exercise it. Every flow runs in a real browser, gets recorded start to finish, and the video is attached right to the pull request, so reviewers watch what happened before they merge.

Runs in a real browserAgents drive your app with real clicks, forms, and navigation against a live sandbox.
Recorded end to endEvery flow is captured on video, so you see exactly what the agent saw.
Attached to the PRThe recording lands in the pull request description. Watch the proof, then merge.

Hand off the boring tickets. Keep the hard engineering.

Not another background agent.

Hand off the bullshit tickets

A preview, not a promise

Your architecture, respected

Configure once. Ship forever.

Why not just use Claude Code?

Why not just use Linear Agents or Cursor Agents?

Works with your favorite stack.

Ship demos, not meetings.

Demo without engineers

Non-technical teammates ship

QA without sync

Built for compliance.

The first Cloud IDE built for the agents era

Every change, tested on camera

Common Questions

How is Kosuke different from Claude Code?

What exactly is a "sandbox"?

How does Kosuke respect my code conventions?

Do I still have full control over what gets merged?

Does Kosuke work with monorepos and private repos?

How does Kosuke handle merge conflicts?

Won't this flood my team with PRs to review?

Is my code secure, and is there any vendor lock-in?

What's "BYOK"? Which LLM provider keys do I need?

What's Dev Mode?