Let yourclients buildwith agent sandboxes.

Connect your codebase to w/handoff and let them build with agents.

Pay-Per-Use AI Budgeting
Git & Container Isolation
Bring your own CI/CD

Iterate faster.

Clients can instantly make changes. No more back-and-forth emails.

Keep the guardrails.

Configure hooks and permissions so client's can't modify your database schemas. Or let them, and require a code review.

Budget costs.

Set the AI budget for a project, or let your client foot the bill. You control the client relationship.

Save time.

Set the groundwork and let your clients vibe code. Jump back in when they need an expert.

Phase 1: Developer Setup

You build the foundation.

Senior engineers control the codebase. Bring your preferred directory structures, databases, and dependencies. Keep CI/CD pipelines intact and lock down core architectural patterns.

  • Use the same envs: Inject any envs you need for your sandbox, just like you would for your deployments. They're secure in your isolated Firecracker VM.
  • Bring your own database: Connect sandboxes to your existing test database. w/handoff pro lets you deploy an isolated database inside the sandbox with a custom dockerfile.
  • Use Javascript, Python... or the language of your choice: Spin up node and python sandboxes instantly. w/handoff pro lets you set up everything you need for your language of choice.
Phase 2: Guardrails

You set the guardrails.

Define the boundaries of sandbox sessions using nested HANDOFF.md files and .handoff configs. Build them custom for your client, or symlink the configs you use for existing agents.

  • HANDOFF.md files: Restrict agent edits to specific files, customize paths, and inject scoped context.
  • Custom hooks: Execute scripts or commands at key lifecycles like pre-turn or validate.
  • Agent skills: Save reusable tools and custom prompt configurations in the .handoff directory to augment agent capabilities.
Read the docs
withhandoff-developer-workspace
.handoff
hooks.json
scripts
deploy.sh
src
components
Button.tsx
utils
db.ts
main.tsx
AGENTS.md
HANDOFF.md
package.json
withhandoff.config.json
withhandoff.config.json
{
  "sandbox": "node",
  "size": "lite",
  "install": "npm install",
  "run": "npm run dev",
  "port": 3000
}
Phase 3: Client Portal

They iterate.

Clients can request style and copy changes using a friendly, chat-based portal. In a single message, they describe what they want to change and see the modifications updated live in their isolated preview sandbox.

Client Portal ChatReady
App Preview
localhost:3000

Standard Tier

Access basic features and standard tools.

  • ✓ 5 Team Members
  • ✓ 10GB Storage
Assistant
Hi! Welcome to your app preview portal. Let me know what changes you'd like to make to the card on the left.
What do you want to change?
Phase 4: Handoff Protocol

They can ship, or hand it back for code review.

Write custom hooks to automatically block pushes to production. Customize the guardrails for the client.

Finish & Submit ChangesProject Sandbox
Simple Pricing model

Bring your own CI/CD.

free

Free to set up lite sandboxes (1/16 CPU, 256MB RAM, 2GB disk) with Python or Node runtime. Pay-per-use AI credits.

  • Lite sandboxes (1/16 CPU, 256MB RAM, 2GB disk)
  • Python or Node runtime support
  • Pay-per-use AI credits & budgeting
  • Clients can purchase overage credits
  • One connection at a time
pro

Includes everything in w/handoff free, plus standard sandboxes, custom Docker images, and multi-connection support.

  • Standard sandboxes (1/2 CPU, 2GB RAM, 8GB disk)
  • Use your own custom Docker image
  • Better support for backend + frontend + DB stacks
  • Multiple connections at a time