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serverAppConfigs/serverAppConfigs-docs/Dankclaw/Hermes-WebUI.md
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Frank c527f35bd4 docs(hermes): persistent SSH-tunnel ingress design for Hermex (tunnel user + restricted key options)
Server-side implementation landed on Dankclaw: dedicated 'tunnel' account
(nologin shell, password-locked, key-only auth), sshd drop-in
99-tunnel.conf scoping AllowTcpForwarding to that user with PermitTTY off,
and permitopen="localhost:8787" key-option guidance so a leaked tunnel key
can only forward to the webui port. WebUI stays loopback-only published.
2026-08-31 06:23:13 -07:00

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---
type: configuration
title: Hermes-WebUI (Hermex server)
description: The hermes-webui compose service on Dankclaw — the loopback-only API server that the Hermex iPhone app talks to over an SSH tunnel.
tags:
- hermes
- hermes-webui
- hermex
- dankclaw
- ssh-tunnel
timestamp: 2026-09-14
---
# Hermes-WebUI (Hermex server)
`hermes-webui` is the [hermes-webui](https://github.com/nesquena/hermes-webui)
server (MIT, third-party) that the **Hermex** iPhone app connects to. It runs
the Hermes agent in-process from the shared `HERMES_HOME`, so it is the *same*
agent — same memory, skills, and sessions — as the [[Hermes]] gateway and the
[[Hermes-Dashboard]].
**Host:** Dankclaw — **Port:** `127.0.0.1:8787` (loopback only) — **Ingress:** SSH tunnel
## Facts
| Item | Value |
|------|-------|
| Image | `docker.io/nousresearch/hermes-agent:latest` (same as the gateway) |
| Command | `python3 /webui/bootstrap.py --foreground` |
| Source checkout | `/home/dank/hermes-webui` on Dankclaw (mounted at `/webui`) |
| Port | `8787`, published to `127.0.0.1` only |
| Auth | `HERMES_WEBUI_PASSWORD` (host `.env`; Hermex signs in with it) |
| Data | shares `/home/dank/hermes-data` with the gateway and dashboard |
| Health | `GET /health` (compose healthcheck + deployer) |
## Why a container, not a host process
The gateway's state files are owned by the container-mapped uid (`109999`,
from rootless Podman's `1 → 100000/65536` subuid range). A fresh rootless
namespace on Dankclaw maps identically (verified with `podman unshare
cat /proc/self/uid_map`), so a second container using the same image reads
and writes the shared volume with exactly the ownership the gateway already
uses. A host-side process running as `dank` (uid 1000) could not read the
gateway's `0600` state files.
## How it works
- `bootstrap.py` creates `/webui/.venv` on first boot, pip-installs the WebUI
and agent requirements, then **execs** `server.py` as one foreground process
(`--foreground`). systemd-free: Podman supervises it via
`restart: unless-stopped`.
- `HERMES_WEBUI_SKIP_ONBOARDING=1` keeps the first-run wizard off; a profile
already exists in `/data` from the gateway.
- The healthcheck `start_period` is 600 s because the very first boot spends
minutes pip-installing into a fresh venv.
## Remote access (Hermex on iOS — persistent SSH tunnel)
Only port `22` is forwarded to Dankclaw at the router, so the webui is
reached through an SSH **local forward** — no extra router ports, no
third-party relay (no Tailscale, no Cloudflare). Implemented 2026-08-31:
- Dedicated `tunnel` account on Dankclaw (`/usr/sbin/nologin` shell, password
locked). Authentication is key-only; the account can do nothing except
authenticate — `ForceCommand /usr/sbin/nologin` kills any session channel
while the transport stays up for port forwarding.
- sshd drop-in `/etc/ssh/sshd_config.d/99-tunnel.conf` scopes
`AllowTcpForwarding yes` to that user only (plus `PermitTTY no`,
`X11Forwarding no`).
- Key options on the authorized key pin the blast radius:
`command="/usr/sbin/nologin",no-pty,restrict,port-forwarding,permitopen="localhost:8787"`
— a leaked tunnel key can only forward to `localhost:8787`, never act as a
general SOCKS/SSH proxy.
- On the phone (client side): create a key on-device (private key never
leaves the device), hand the **public** key to the admin who appends it to
`/home/tunnel/.ssh/authorized_keys`, then connect from the SSH client:
- In-network target `192.168.0.143:22`, off-network target the public
hostname (router forwards only port 22 → Dankclaw) — same forward config
otherwise.
- Local forward `127.0.0.1:8787 → localhost:8787`; Hermex server URL is then
`http://localhost:8787` in both locations.
- For a *persistent* tunnel on iOS, Secure ShellFish's personal-VPN mode
(Network Extension keeps the tunnel up and routes `127.0.0.0/8` through
it); Termius works but only while its session is connected — iOS allows no
background SSH daemon.
```mermaid
graph LR
A[Hermex app] -->|http://localhost:8787| B[SSH local forward on iPhone<br/>persistent via personal VPN]
B ==>|encrypted SSH to port 22| C[Dankclaw sshd<br/>tunnel user, forced nologin]
C --> D["hermes-webui 127.0.0.1:8787"]
D --> E["/home/dank/hermes-data (shared agent state)"]
```
## Deployment
```
./scripts/deploy.sh dankclaw --service hermes-webui
```
The planner maps changes to the `hermes-webui` compose block (and only that
block) to this service, so gateway and inference restarts stay isolated.
Before first deploy, set a strong `HERMES_WEBUI_PASSWORD` in the live
`dankclaw/.env`.
## Gotchas
- The `/webui` mount is **rw on purpose**: `bootstrap.py` creates `.venv` in
the repo root. Do not flip it to `:ro`.
- Never publish `8787` beyond loopback without keeping the password set —
the webui can run agent commands.
- The webui and the gateway share one data volume. A config change made on one
side takes effect when the other restarts (same caveat as the dashboard).
- `bootstrap.py` auto-installs a Hermes Agent if it cannot find one; in this
image the agent is already present, so that path should never fire. If the
log shows an install attempt, the image changed — re-verify the entrypoint.
# Citations
- hermes-webui README (env vars, `--foreground`, `/health`): https://github.com/nesquena/hermes-webui
- Hermex setup model (server URL + password; Cloudflare/Tailscale are optional, not required): https://hermexapp.com/
## See Also
- [[Hermes]] — the agent and its Signal gateway
- [[Hermes-Dashboard]] — the LAN browser management UI
- [[Dankclaw Stack]]