Egress Firewall#

Restrict outbound network access from sandboxes.

Enable#

claustro up --firewall

Or in claustro.yaml:

firewall:
  enabled: true
  allow:
    - custom-registry.company.com
    - api.openai.com

Default whitelist#

When enabled, the following domains are always allowed:

• api.anthropic.com — Anthropic API
• registry.npmjs.org — npm
• pypi.org — Python packages
• github.com — Git operations
• archive.ubuntu.com, security.ubuntu.com — System updates

Docker internal networks (172.16.0.0/12, 192.168.0.0/16, 10.0.0.0/8) are always allowed for compose-sibling services.