Deploying the demo over Tailscale (and the LAN)

How the racketmaximus reference implementation is shared privately over a Tailscale tailnet, how to also answer on the local network, plus the (optional, gated) paths to trusted HTTPS and a public URL.

Pick your reach first — TELEMACHUS_BIND takes a single interface, so the value you choose is the whole exposure decision:

`TELEMACHUS_BIND`	Reachable from	Use when
`127.0.0.1` (default)	this host only	developing
`100.70.154.54`	tailnet devices	sharing with your own devices, anywhere
`0.0.0.0`	tailnet and LAN and localhost	you're on the same network and the tailnet

There is no value that means "tailnet + LAN but nothing else" — 0.0.0.0 binds every interface, including the lxcbr0/docker0 bridges. On a trusted network that is fine; it is not a substitute for a firewall.

Current setup — private, tailnet-only

The server binds to this host's tailnet IP, so any device signed into the same tailnet can reach it. Tailscale is WireGuard, so traffic is encrypted end-to-end — plain HTTP is already private on the wire; the only thing missing vs. HTTPS is the browser padlock.

cd refimpl/racketmaximus
export PLTCOLLECTS="$(pwd)/pkgs:"
TELEMACHUS_BIND=100.70.154.54 \                             # this host: `tailscale ip -4`
TELEMACHUS_MODEL_URL=http://127.0.0.1:11434/v1/chat/completions \
TELEMACHUS_MODEL=qwen2.5:7b \                               # ollama (OpenAI-compatible)
racket server/main.rkt

URL: http://<tailnet-ip>:8835 — this host is red5buntu / 100.70.154.54
Model: qwen2.5:7b via ollama — non-reasoning, streams cleanly (avoid the reasoning models like qwen3.5:*, whose answer lands in a reasoning field and reads as a blank reply here).
Bind: TELEMACHUS_BIND selects the interface (default 127.0.0.1).

Also on the local network (LAN)

Tailscale routes over its own interface, so a tailnet-bound server is invisible to a laptop sitting on the same Wi-Fi unless that laptop uses the tailnet address. To answer on both, bind every interface:

TELEMACHUS_BIND=0.0.0.0 racket server/main.rkt     # + the model/db env from above

LAN URL: http://10.0.0.244:8835 — this host on eno1 (ip -4 -o addr show eno1)
Tailnet URL: http://100.70.154.54:8835 — still works, unchanged
Localhost: http://127.0.0.1:8835 — also comes back

The firewall will block it until you say otherwise

ufw is active on this host with DEFAULT_INPUT_POLICY="DROP". Tailscale is unaffected — it installs its own iptables rules outside ufw's INPUT chain, which is why the tailnet path works with no firewall change. The LAN path does not. Open the port once, scoped to the local subnet rather than the world:

sudo ufw allow from 10.0.0.0/24 to any port 8835 proto tcp
sudo ufw status                                   # confirm the rule landed

Testing from the host itself proves nothing here. curl http://10.0.0.244:8835 run on this box routes through loopback, which ufw permits — so it returns 200 whether or not the LAN is actually allowed in. Verify from the other machine.

What LAN exposure means

Anyone on the local network can reach the app — including the public beta signup at /, which by design takes submissions without an account. That is a different audience from the tailnet (your own devices). Before binding 0.0.0.0 on a network you don't control: rotate alice off s3cret, and remember the seeded demo login works for anyone who reaches the page.

Demo accounts (runtime state, not in git)

Login	Password	Role	Shows
`demo`	`Telemachus2026`	member	normal user — chat, notes, usage; no admin
`alice`	`s3cret`	operator	admin — members, quotas, admin status

Change a password in the UI (Team → Change your password) or POST /api/password. alice is on the first-run default — rotate it before any wider exposure.

60-second demo script

Log in as demo → Chat (real model, streams token-by-token); Notes (a private + a team note are seeded — try Share).
Flip EN / 日本語 — the chrome and server errors both localize.
Log in as alice (operator) → Team (add a member), Usage (raise a quota live), Admin.
As a member, trigger an admin action → localized 403 (RBAC enforced server-side).

Trusted HTTPS on the tailnet (optional) — `tailscale serve`

Real Let's Encrypt cert on your MagicDNS name (green padlock), still tailnet-only.

Admin console → DNS (login.tailscale.com/admin/dns): enable MagicDNS and HTTPS Certificates. (Check: tailscale status --json | grep CertDomains — now populated with red5buntu.quokka-hippocampus.ts.net, i.e. already done.)
On this host, once: sudo tailscale set --operator=$USER (so serve runs without root)

Run the app on localhost (TELEMACHUS_BIND=127.0.0.1), then:

tailscale serve --bg 8835          # → https://<host>.<tailnet>.ts.net

The app's own TELEMACHUS_TLS=1 self-signed cert is not recommended for the tailnet — it just adds a browser warning. Let Tailscale terminate TLS instead.

Public URL (later, deliberate) — `tailscale funnel`

Exposes the app to the public internet. Only with a hardened login.

Everything under serve above, plus:

Admin console → Access Controls: grant this node the Funnel attribute:
```
"nodeAttrs": [ { "target": ["red5buntu"], "attr": ["funnel"] } ]
```
Then: tailscale funnel --bg 8835 → public https://<host>.<tailnet>.ts.net

Before funnelling:

Rotate alice off s3cret; remember the seeded demo login is then reachable by anyone with the URL.
Prototype-grade: no rate limiting, bots will probe. Enable Funnel only for the call, then tailscale funnel reset and stop the server.