Castari

Hey! We’re Jacob Wright & Cambree Bernkopf, founders of Castari.

TL;DR

Castari lets teams deploy AI agents to secure, autoscaling sandboxes in seconds.

You write agent logic with the Claude Agent SDK (other frameworks coming soon). We turn it into a production-grade endpoint.

We’re especially focused on:

• Teams building internal agents (ops, support, data, eng workflows).
• Companies whose core product is an agent built on Claude Agent SDK and need a safe, reliable way to run it.

Launch Video:

https://youtu.be/81K80OivtAc

The Problem:

Serious agents are not just a single API call. Agents need a computer.

They execute code, call tools and browsers, run for minutes instead of milliseconds, and touch sensitive systems. Most teams end up rebuilding the same fragile setup:

• Homegrown agent harnesses
• Sandboxes, file systems, and queues stitched together
• Logs and traces scattered across many services
• Ad hoc snapshots and risky secret handling

The result:

• Every agent needs its own mini runtime
• Debugging one agent run feels like detective work
• Adding a new agent feels like starting a new infra project

Good agents stall at “cool demo” instead of reaching production. Deploying agents becomes a full-time infrastructure problem.

How Castari solves it

We’re building Castari to be the natural runtime for AI agents built on Claude Agent SDK. We wrap the entire agent in a sandbox, deploy it, and provide you with an endpoint url that auto-scales as requests come in. No need to write code in your tools to manage your sandbox lifecycle.

1. Drop in a config file → get a production runtime

In your Claude Agent SDK repo:

• Add a castari.yaml (entrypoint, tools, env vars)
• Run castari deploy

That’s it. Your agent is now running in a secure sandbox with an endpoint, UI, and observability.

Whether that agent is:

• an internal system your team uses
• a customer-facing agent that is your product

the deployment workflow is identical and boring (in the good way).

2. Sandboxing & safety, built-in

• Every run executes in an isolated sandbox designed for tool-using agents
• You design the behavior; we handle isolation and scaling
• No more duct-taping together sandbox primitives for specific tools

Bottom line: You keep building on Claude Agent SDK the way you already are — for internal workflows or core products. Castari turns that into a safe, observable, production-ready runtime.

Why Castari is different

E2B, Modal, Daytona, Cloudflare (and friends) give you powerful sandbox and compute primitives.

Castari sits one layer up:

Castari wraps around your Claude Agent SDK-based agents so you can define them declaratively and run them in secure sandboxes, without owning the underlying sandbox lifecycle.

• Agent-first semantics: runs, sessions, tools, snapshots are native concepts we manage.
• Zero framework lock-in: remove Castari and your agent still runs on vanilla Claude Agent SDK; keep Castari and your infra team gets its life back.
• Focused start: deeply integrated with Claude Agent SDK today, with the same “drop-in config” experience coming to other frameworks next.

We’re building the runtime we wish existed for agents.

Why we’re working on this

While I was leading the FDE team at RunPod:

• Built and shipped AI infrastructure and agents for Fortune 500s and fast-growing startups
• Watched the same loop repeat: agent works in a notebook → weeks disappear into infra glue → nobody trusts the system, production release gets delayed (over and over again).

Additionally, while @Cambree Bernkopf and I scaled our AI consumer app to 2m+ members, our biggest issues were getting our agents to work reliably in production.

The pattern is clear: agents deserve a first-class runtime, the way frontends got one.

Castari is our bet that:

• Sandboxing & safety should be built-in, not bolted on
• Going from “prototype” to “production-safe” should be one config file, not a quarter-long project
• AI teams should ship agents, not infrastructure.

Ask: early pilot access

We are opening a limited pilot for:

• Teams building internal agents who need a safer, more reliable runtime
• Companies building agent centric products that need to run in production without bespoke infra

If that is you and you are tired of wrestling with sandboxes, observability, and brittle tooling:

→ Email jacob@castari.com with subject “Castari Pilot” and 2 to 3 sentences about your agent stack and use case.
→ Check out our open source repo for using any model with Claude Agent SDK on GitHub.
→ Join the waitlist on castari.com to hear about our first releases.

Jacob, Cambree, and the Castari team