Agents that improve themselves
Define an agent, connect tools and MCP servers, and deploy. The harness runs outside the sandbox and continuously learns from every run, so your agents become more reliable over time.
Agents need their own machine
Give your agents aReal
Computer
Celesto provides secure, isolated computers that AI agents can use to browse, code, and get real work done.
Supported by
Open-source core. Self-host or use our cloud.
SmolVM
Apache-2.0The microVM that boots every Celesto sandbox. Run it on your own infrastructure — no account, no lock-in.
$ smolvm sandbox create
GitHub239stars
Celesto Cloud
ManagedSame CLI, same SDK, zero infrastructure. Sandboxes boot in seconds and you pay only while they run.
$ celesto computer create
Start free380developers building
Core features
One platform to build, run, and distribute agents.
A real computer for every agent
Hardware-isolated microVMs boot in about 500ms with a shell, filesystem, and full browser. Pause, resume, and snapshots preserve state, while network controls keep your data secure.
Deploy agents to your customers
Ship agents under your own product, then expose them through the channels your customers already use — MCP servers, Telegram, APIs, and more. Deploy once, reach every surface.
Everything your agent needs to run reliably.
Production sandboxes with the primitives that make long-running agents practical — forking, streaming, and instant recovery out of the box.
Forking
Branch a running sandbox into parallel copies. Test variants, roll back, or fan out work — without reprovisioning.
Instant Boot
Cold start to running in under 3 seconds. No waiting for provisioning or image pulls.
~2scold start
Pause & Resume
Suspend sandboxes when idle — resume in milliseconds. Pay only for active compute.
resumed
0.4sBrowser Use
Give agents a full browser inside the sandbox. Navigate, click, fill forms, and extract data — headless or streamed live to your screen.
noVNC
live stream
Persistent Storage
Attached volumes survive restarts and snapshots. Your agent's data is always where it left off.
/data
/models
/cache
CLI & SDK Access
Full programmatic control. Execute commands, stream output, and manage sandboxes from code or terminal.
$ celesto computer run my-sbx "python train.py"
Run untrusted code and agents
Execute AI code and agents in disposable sandboxes—built for workflows, long-running agents, and computer-use agents.
$ pip install celesto $ celesto computer create --cpus 2 --memory 2048 Name: einstein Status: running $ celesto computer ssh einsteinroot@celesto:/# python3 -c "print('Hello from the cloud!')"Hello from the cloud! $ celesto computer run einstein "uname -a"Linux celesto 6.8.0 x86_64 GNU/Linux $ celesto computer delete einstein✓ Computer einstein deletedNo setup needed — sign up and start running
Works with every AI agent and framework
Celesto provides an open-source framework and CLI for lightweight, secure sandboxes to run AI-generated code.
LangSmith
OpenClaw
Hugging Face
Pydantic AI
OpenAI Agents
Docker
Qwen
Local LLM
Claude
NVIDIA
DeepSeek
Meta
Mistral
Nous Research
Live sandbox apps
Run a live service from the same sandbox.
Start Express, FastAPI, webhooks, dashboards, or an agent API inside an isolated computer. Publish a port and Celesto gives you a public URL - no separate deploy service to wire up.
No extra deploy service
Run the app and publish the port from Celesto. No Vercel-style detour or proxy glue.
A real public URL
Share an Express app, FastAPI server, dashboard, webhook receiver, or agent backend.
Still isolated
The service is reachable, but the runtime stays inside the disposable sandbox.
p-spark-8000.celesto.dev
Built and deployed with Celesto
A public web app, served straight from the sandbox.
Open live appnpmport 8000
$ npm run dev -- --port 8000
$ celesto computer port publish
port 8000
$ npm run dev -- --port 8000
ready on http://0.0.0.0:8000
$ celesto computer port publish
Port published
RunPublishShare
p-spark-8000.celesto.dev
Built and deployed with Celesto
A public web app, served straight from the sandbox.
Open live appnpmport 8000
Agent observability
Full observability, Know exactly why agents fail.
Every agent execution is automatically traced. Debug complex workflows, inspect tool calls, and optimize performance without writing a single log line.
Automatic Tracing
Built into Celesto: every agent call is traced automatically, no configuration needed.
Live Streaming
Watch traces stream in real-time as your agents run in production.
trace_id: 8f23a0...
Execution Path
Span Details
450msInput
{"action": "get_order", "id": "12345"}Output
{
"id": "12345",
"status": "shipped",
"carrier": "FedEx",
"tracking": "7890123456"
}Start free, scale as you grow
No hidden fees. No surprises. Cancel anytime.
Free
Try a real cloud sandbox with a clear monthly limit.
$0/mo
No credit card required
What's included
- 30 Nano sandbox-hours/month
- 1 concurrent active sandbox
- Nano: 1 shared vCPU and 512 MB RAM
- Hard stop at the monthly limit
- No credit card required
Start here
Nano
Keep a lightweight sandbox available all month.
$5/mo
What's included
- 750 Nano sandbox-hours/month
- 2 concurrent active sandboxes
- Nano: 1 shared vCPU and 512 MB RAM
- Hard stop with no overage charges
- Persistent disk up to 20 GB
Builder
For developers building and testing production agents.
$29/mo
What's included
- 300 standard sandbox-hours/month
- 10 concurrent active sandboxes
- Nano, Small, Standard, and Large sizes
- $0.10/additional standard sandbox-hour
- OpenClaw and Hermes included
Growth
For teams running many agents in parallel.
$199/mo
What's included
- 2,500 standard sandbox-hours/month
- 100 concurrent active sandboxes
- Nano, Small, Standard, and Large sizes
- $0.08/additional standard sandbox-hour
- Managed runtimes, shared access, and logs
Enterprise
For secure agent infrastructure at scale.
Custom
What's included
- Custom usage and concurrency
- VPC/on-prem deployment
- SSO and audit logs
- Windows sandboxes
- Custom retention and support