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Outcall
Default-deny egress control for agent containers
An open-source host-level firewall daemon and operator surface for governing outbound traffic from Docker agent containers with a default-deny posture across nftables, DNS filtering, and an HTTP proxy.
Tag
Infra Security · Open Source
Duration
Ongoing
Role
Positioning · Security UX · Frontend
Outcall leads with the real operator problem: putting Claude Code or Codex in a default-deny box, then making every outbound permission explicit, inspectable, and enforceable.
Posture
Default-deny
Layers
L3 + L7
License
Apache-2.0
◇ The problem
Where they were stuck.
Teams running coding agents needed more than loose network isolation. They needed a way to isolate containers, default-deny outbound traffic, and grant narrowly-scoped access by hostname, method, path, and agent identity without relying on agent self-restraint.
◇ Our approach
How we shipped it.
- 01
Turned the product story into a concrete operator narrative: one command to start, one daemon on the host, one bridge that owns outbound policy, and six surfaces that share the same source of truth.
- 02
Explained the enforcement model in plain language instead of security jargon alone, showing how nftables, DNS filtering, and the HTTP proxy work together.
- 03
Framed the website around the exact audience trigger: operators who want Claude Code or Codex inside a default-deny box with auditable outbound access.
- 04
Shipped a docs-and-product surface that makes the security posture legible before users reach the repo, the specs, or the daemon internals.
◇ Stack
What it's made of.
RustNext.jsDockernftablesHTTP proxyDNS filter
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