Triple-C/container/skills/pia-vpn/SKILL.md

---
name: pia-vpn
description: Connect this container's traffic through a PIA VPN tunnel over WireGuard, or diagnose one that is not working. Use when asked to enable, route through, check, or tear down a VPN, when traffic needs to leave from a different location, or when DNS or connectivity broke after a VPN was brought up.
---

# PIA VPN

Bring this container's traffic out through Private Internet Access over
WireGuard, using the API PIA documents for headless use.

Run `sudo ~/.claude/skills/pia-vpn/pia-wg.sh` with `up`, `up --full`, `down` or
`status`. Read the rest of this page before the first `up --full` — two of the
behaviours below are actively misleading if you meet them without warning.

## Before anything else: what the toggle does not do

Triple-C's **VPN support** setting grants three things — `CAP_NET_ADMIN`, the
`/dev/net/tun` device, and the `net.ipv4.conf.all.src_valid_mark` sysctl — and
stops there. It starts no client, builds no tunnel and changes no route.

So "the VPN is enabled but traffic isn't going through it" is normally not a
fault. It means the capability is present and nothing has used it yet. Check
with `status` before assuming something is broken.

If the toggle is off, the script says so and names the setting. It cannot be
turned on from inside the container; the user changes it in Config → Runtime,
and it recreates the container on the next start (home and `.claude` volumes
are preserved — it is not a Reset).

## Two modes

| | routes | use when |
|---|---|---|
| `up` | only `1.1.1.1/32` | verifying the tunnel works without disturbing anything |
| `up --full` | all public traffic | you actually want traffic leaving via PIA |

Prefer `up` first. It proves the handshake, credentials and region are good
while your own connectivity is untouched, so a failure is cheap.

**`up --full` routes Claude Code's own API traffic through PIA.** If the tunnel
drops, that traffic stops until it recovers or you run `down`. Say so before
running it — the user may be mid-session, and they will experience the failure
as Claude going away, not as a VPN problem.

## Trap 1: a full tunnel takes DNS with it

The container resolves through an address on the Docker network — under Docker
Desktop, `192.168.65.7` — which sits **outside** the container's own subnet. A
default route of `0.0.0.0/0`, or the `0.0.0.0/1` + `128.0.0.0/1` pair, captures
it and posts every lookup into a tunnel that cannot carry private traffic.

Nothing resolves after that. The visible symptom is Claude Code reporting it
cannot connect, because `api.anthropic.com` no longer resolves:

```
$ curl https://api.anthropic.com/v1/messages
* Could not resolve host: api.anthropic.com     (rc=6)
```

`pia-wg.sh` already handles this: it routes `10.0.0.0/8`, `172.16.0.0/12`,
`192.168.0.0/16` and `169.254.0.0/16` back via the original gateway, then pins
PIA's own resolvers through the tunnel with `/32` routes that outrank the
`10/8` exclusion. If you ever route traffic by hand, you owe both halves — the
exclusions *and* a resolver reachable from wherever you pointed the default.

## Trap 2: an IP-literal health check cannot see a dead resolver

`curl https://1.1.1.1/cdn-cgi/trace` needs no DNS, so it returns a cheerful
PIA exit address while name resolution is entirely broken. A tunnel verified
that way looks perfect and works for nothing.

`status` resolves a real name for this reason. Trust its `DNS:` line, and if
you check by hand, resolve a name rather than fetching an address.

## Trap 3: no tunnel survives a restart, and it fails open

The network namespace is rebuilt every time the container starts, and nothing
inside reconnects anything. After a stop/start, Reset or any config change that
recreates the container, the interface and its routes are gone.

State under `/run/pia-wg` rides the snapshot and persists, so leftover files
make it look as though the tunnel is still configured. It is not. Traffic goes
out the real address with no error and nothing visibly different.

Never infer from `/run/pia-wg` that a tunnel is up. Run `status` — if the
handshake line is missing, there is no tunnel. Re-run `up` after every start.

## Credentials

Two lines in `~/pia-creds` — username, then password:

```
p1234567
your-password
```

Set `PIA_CREDS` to use a different path. Treat the contents as secret: never
print the file, never echo the values, and never include them in a commit, a
log or a message. The script reads it directly and does not echo it.

## Regions

Defaults to `us_chicago`. Override with `PIA_REGION`:

```bash
sudo PIA_REGION=uk_london ~/.claude/skills/pia-vpn/pia-wg.sh up --full
```

List the ids:

```bash
curl -s https://serverlist.piaservers.net/vpninfo/servers/v6 \
  | head -1 | jq -r '.regions[].id'
```

## Verifying

`status` prints three things — handshake, DNS, and the public address:

```
  latest handshake: 2 seconds ago
  transfer: 92 B received, 180 B sent
DNS: ok (via 10.0.0.243 10.0.0.242)
public IP: 64.113.5.244
```

All three matter. A handshake with `DNS: BROKEN` is trap 1. A handshake with an
unchanged public address means routing did not take — you are probably in `up`
rather than `up --full`.

## Tearing down

`down` restores `resolv.conf` from its backup and removes exactly the routes
that were added, in reverse order, then deletes the interface. It is safe to
run when nothing is up. Confirm afterwards that the public address is back to
the container's own.

## What this deliberately does not do

- **No killswitch.** Blocking non-tunnel egress needs `iptables`, which is not
  in the image, and would cut Claude Code's API traffic whenever the tunnel is
  down. If the user needs guaranteed egress rather than convenient egress, say
  so plainly rather than improvising one — it is a real design decision.
- **No autostart.** There is no service manager in the container and Triple-C
  has no start hook, so nothing can re-establish the tunnel automatically.
- **Not PIA's desktop client.** `pia-daemon` and `piactl` are installable but
  cannot work headless: the daemon never accepts a client connection without
  the GUI, and `piactl --help` states that connecting requires it. If you find
  one installed, it is not a working alternative to this script.