Publish ports from a sandboxed computer

Services inside a Celesto computer are private by default. This isolation is useful for running agents, notebooks, APIs, and preview apps safely, but it also means you need to expose a service before you can open it in a browser or send a webhook to it. Port publishing creates a public HTTPS URL that forwards traffic to a port inside the computer, so you can preview, test, and share running services without deploying them elsewhere. A port is the numbered address a service listens on. For example, a local development server might listen on port 8000.

When to publish a port

Publish a port when you need to:

Preview an app generated by an agent.
Share a local API running inside a computer.
Receive webhooks during a test run.
Inspect a notebook, dashboard, or development server.

Publish a service

The following example starts a simple HTTP server on port 8000, publishes the port, prints the public URL, lists published ports, and then removes the published port.

Start a service and publish its port

Start a server inside the computer, publish the port, and open the returned HTTPS URL in your browser.

from celesto import Computer


computer = Computer(template_id="coding-agent")
computer.run("python3 -m http.server 8000 &")

url = computer.publish_port(8000)
print(url)

published_ports = computer.list_published_ports()
print(published_ports)

computer.unpublish_port(8000)
computer.delete()

import { Computer } from "@celestoai/sdk";

const computer = await Computer.create({ templateId: "coding-agent" });
await computer.run("python3 -m http.server 8000 &");

const url = await computer.publishPort(8000);
console.log(url);

const publishedPorts = await computer.listPublishedPorts();
console.log(publishedPorts);

await computer.unpublishPort(8000);
await computer.delete();

celesto computer create --template coding-agent
celesto computer run einstein "python3 -m http.server 8000 &"
celesto computer port publish einstein
celesto computer port list einstein
celesto computer port unpublish einstein
celesto computer delete einstein

The publish command returns a public HTTPS URL that forwards traffic to the service running inside the computer.

Inspect published ports

Use the list command when you need to confirm which ports are currently exposed for a computer.

CLI

celesto computer port list einstein

Each published port includes the internal port, the public URL, and its current status.

Published port fields

integer

Port inside the computer that receives forwarded traffic.

string

Public HTTPS URL for the published service.

string

Current published-port state.

Clean up published ports

Published URLs are intended for short-lived development and testing workflows. Remove a published port when you no longer need external access to the service.

CLI

celesto computer port unpublish einstein

For short-lived previews, unpublish the port before deleting the computer.

Troubleshooting

If the published URL does not load, check that the service is still running inside the computer and listening on the expected port.

CLI

celesto computer run einstein "curl -I http://localhost:8000"

If the command fails, restart the service and publish the port again.

Treat published URLs as public. If the service exposes sensitive data or actions, add authentication to the service before sharing the URL.

Start Here

Features

Guides

Agents and Integrations

Publish ports from a sandboxed computer

When to publish a port

Publish a service

Inspect published ports

Published port fields

Clean up published ports

Troubleshooting

​When to publish a port

​Publish a service

​Inspect published ports

​Published port fields

​Clean up published ports

​Troubleshooting

When to publish a port

Publish a service

Inspect published ports

Published port fields

Clean up published ports

Troubleshooting