Your cloud resources and costs

What Cua creates in your AWS, Google Cloud or Modal account, what it costs per hour, and the notes for each cloud.

What Cua creates#

Cloud	Per sandbox	Shared
AWS	One EC2 instance and its disk. Docker runs the image on it.	One security group with no inbound rules, in the region's default VPC.
Google Cloud	One Compute Engine instance and its disk. Docker runs the image on it.	A network with no inbound rules, so the project's default firewall rules never apply to it.
Modal	One Modal sandbox running the image.	Nothing.

Nothing else is created: no IAM users or keys, no change to existing networks, security groups or firewall rules.
The VM installs only Docker. The image carries its own cua-spacesd.
Every resource carries these tags (labels on Google Cloud):

Tag Value
cua-managed true
cua-owner This cua home's owner id
cua-space The sandbox's name
cua-machine Its relay machine
cua-created-by The cua version
cua-expires When it expires (Unix seconds)
Every resource is recorded in ~/.cua/cloud/state.json before the cloud call, with its cloud id once it has one.

Costs#

cua cloud status shows the estimated on-demand price of each image family per hour while it runs (compute and disk, not network). A stopped VM bills only its disk.

Cloud	`linux`	`linux-slim`
AWS	`t4g.medium` (arm64), about $0.04/hour	`t4g.small`, about $0.03/hour
Google Cloud	`e2-medium`, about $0.04/hour	`e2-small`, about $0.03/hour
Modal	1 core (2 vCPU) and 4 GiB, about $0.24/hour	the same

Windows and Omarchy are not offered yet. They run as VMs inside the cloud's VM, which needs a nested-virtualization machine type; cua cloud status says so next to them.
macOS is not offered. On AWS it would need an EC2 Mac dedicated host, which has a 24-hour minimum.

Per-cloud notes#

AWS:
- One region per connection (--region, else the profile's). Profiles, SSO and assume-role profiles from ~/.aws work as the AWS CLI's do.
- The instance allows only IMDSv2 with a hop limit of 1, so the sandbox's containers cannot read the instance's metadata (or its user data). It has no key pair and no instance profile.
- A new account's vCPU quota may be low. cua cloud test aws does not read it yet; a create past it fails with AWS's own message.
Google Cloud:
- One project and zone per connection (--project, --region, --zone).
- The instance has no service account, so nothing on it can call Google APIs. Its containers reach the metadata server only for DNS.
- cua cloud test gcp says when the Compute Engine API is disabled.
Modal:
- One environment per connection (--environment) and a ~/.modal.toml profile (--profile).
- Sandboxes run under gVisor by default; --runtime microvm uses Modal's VM runtime. Neither has /dev/kvm, so only Linux images run.
- A sandbox cannot be stopped and started, and lives at most 24 hours.
- Cua talks to Modal through cua-modal-helper, which uses Modal's official Go SDK. Build it with go build in libs/cua/crates/cua-contrib/modal-helper and put it next to cua, on PATH, or in CUA_MODAL_HELPER.

What Cua creates#

Cloud	Per sandbox	Shared
AWS	One EC2 instance and its disk. Docker runs the image on it.	One security group with no inbound rules, in the region's default VPC.
Google Cloud	One Compute Engine instance and its disk. Docker runs the image on it.	A network with no inbound rules, so the project's default firewall rules never apply to it.
Modal	One Modal sandbox running the image.	Nothing.

Nothing else is created: no IAM users or keys, no change to existing networks, security groups or firewall rules.

The VM installs only Docker. The image carries its own cua-spacesd.

Every resource carries these tags (labels on Google Cloud):

Tag	Value
`cua-managed`	`true`
`cua-owner`	This cua home's owner id
`cua-space`	The sandbox's name
`cua-machine`	Its relay machine
`cua-created-by`	The cua version
`cua-expires`	When it expires (Unix seconds)

Every resource is recorded in ~/.cua/cloud/state.json before the cloud call, with its cloud id once it has one.

Costs#

cua cloud status shows the estimated on-demand price of each image family per hour while it runs (compute and disk, not network). A stopped VM bills only its disk.

Cloud	`linux`	`linux-slim`
AWS	`t4g.medium` (arm64), about $0.04/hour	`t4g.small`, about $0.03/hour
Google Cloud	`e2-medium`, about $0.04/hour	`e2-small`, about $0.03/hour
Modal	1 core (2 vCPU) and 4 GiB, about $0.24/hour	the same

Windows and Omarchy are not offered yet. They run as VMs inside the cloud's VM, which needs a nested-virtualization machine type; cua cloud status says so next to them.

macOS is not offered. On AWS it would need an EC2 Mac dedicated host, which has a 24-hour minimum.

Per-cloud notes#

AWS:

One region per connection (--region, else the profile's). Profiles, SSO and assume-role profiles from ~/.aws work as the AWS CLI's do.
The instance allows only IMDSv2 with a hop limit of 1, so the sandbox's containers cannot read the instance's metadata (or its user data). It has no key pair and no instance profile.
A new account's vCPU quota may be low. cua cloud test aws does not read it yet; a create past it fails with AWS's own message.

Google Cloud:

One project and zone per connection (--project, --region, --zone).
The instance has no service account, so nothing on it can call Google APIs. Its containers reach the metadata server only for DNS.
cua cloud test gcp says when the Compute Engine API is disabled.

Modal:

One environment per connection (--environment) and a ~/.modal.toml profile (--profile).
Sandboxes run under gVisor by default; --runtime microvm uses Modal's VM runtime. Neither has /dev/kvm, so only Linux images run.
A sandbox cannot be stopped and started, and lives at most 24 hours.
Cua talks to Modal through cua-modal-helper, which uses Modal's official Go SDK. Build it with go build in libs/cua/crates/cua-contrib/modal-helper and put it next to cua, on PATH, or in CUA_MODAL_HELPER.