Vast.ai

If you're using Vast.ai as a cloud provider for Cirun, this is how you would give Cirun access to your Vast.ai account, for it to be able to create GPU runners.

• Go to your Vast.ai Account and generate an API key
• Paste your API key in the "Cloud" Tab of Cirun Dashboard under the Vast.ai section

Configuration

Vast.ai runners are GPU-first. The GPU type and count are specified via instance_type, and the environment is defined by a Docker image (container mode) or a VM image (VM mode).

Container Mode

The default mode runs the runner inside a Docker container with SSH access:

runners:
  - name: vastai-gpu-runner
    cloud: vast_ai
    instance_type: 1xRTX_4090
    machine_image: nvidia/cuda:12.0.0-base-ubuntu22.04
    labels:
      - cirun-vastai-gpu
    extra_config:
      disk_space: 30

VM Mode

For workloads that need a full virtual machine instead of a container, set vm: true in extra_config and use a Vast.ai VM image:

runners:
  - name: vastai-gpu-vm-runner
    cloud: vast_ai
    instance_type: 1xRTX_4090
    machine_image: vastai/kvm:ubuntu_cli_22.04-2025-11-21
    labels:
      - cirun-vastai-gpu-vm
    extra_config:
      disk_space: 30
      vm: true

Instance Type

The instance_type field specifies the number of GPUs and the GPU model in the format {count}x{gpu_model}:

instance_type: 1xRTX_4090        # 1x RTX 4090
instance_type: 4xA100_SXM         # 4x A100 SXM
instance_type: 2xH100             # 2x H100
instance_type: 8xA100_SXM4_80GB   # 8x A100 SXM4 80GB

Use underscores in place of spaces for GPU model names.

Machine Image

For container mode, use any Docker image (e.g. nvidia/cuda:12.0.0-base-ubuntu22.04). For VM mode, use a Vast.ai VM image (e.g. vastai/kvm:ubuntu_cli_22.04-2025-11-21).

Region

Region is optional. When specified, use a country code to restrict which datacenter the runner is placed in:

region: US

Extra Configuration

Option	Type	Description
disk_space	number	Minimum disk space in GB
min_ram	number	Minimum RAM in GB
vm	boolean	Use VM mode instead of container mode

extra_config:
  disk_space: 30
  min_ram: 8
  vm: true