dsh-web-lan-access
UI & ExperienceAcidGr/dsh-web-lan-access
LAN/remote access support for DeepSeek Harness Web UI: injects a crypto.randomUUID polyfill via index-tap to fix RPC failures on insecure origins, and binds to 0.0.0.0.
- deepseek-harness
- dsh
- dsh-plugin
README
dsh-web-lan-access
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LAN / remote access support for the DeepSeek Harness Web UI.
The problem
The Web UI calls crypto.randomUUID() in boot-critical paths (RPC id minting, message ids, draft attachments). That Web API exists only in secure contexts (HTTPS, or http://localhost / http://127.0.0.1). When the UI is served over plain HTTP from a non-loopback address — a LAN IP, a Tailscale IP, or a hostname — crypto.randomUUID is undefined, every RPC throws, and sessions and models never render.
The fix
A host-side plugin that uses the webserver's official index-tap extension point (webServer.tapIndex) to inject a small polyfill (RFC 4122 v4 built on crypto.getRandomValues, which is available on insecure origins) as the first script in <head>, before the boot manifest and the shell entry. On secure origins the polyfill is a no-op.
- No product source modified; fully reversible
- Version-independent (it only transforms the served
index.html) - Platform-independent (Linux / macOS / Windows / Android)
Install
Bundle install (recommended)
Installed from npm:
dsh plugin --profile web add dsh-web-lan-access
(No npm / local development — point pnpm at the repo instead:
dsh plugin --profile web add github:AcidGr/dsh-web-lan-access
)
Restart dsh web, then hard-refresh the browser.
Manual install (no pnpm / offline)
PROFILE="$DSH_HOME/profiles/web" # adjust DSH_HOME and profile name
mkdir -p "$PROFILE/plugins" "$PROFILE/node_modules/@dsh-profile"
cp -r dsh-web-lan-access "$PROFILE/plugins/lan-access"
ln -sfn ../../plugins/lan-access "$PROFILE/node_modules/@dsh-profile/lan-access"
# append to $PROFILE/cordis.patch.yml:
# - insert:
# - id: lan-access
# name: '@dsh-profile/lan-access'
Usage
The plugin is self-contained: its bundle patch sets the webserver bind host to 0.0.0.0 directly (the CLI flag --host 0.0.0.0 is hard-rejected for safety on newer harness versions, but the webserver config still accepts it — so no source changes and no --host flag are needed; the CLI --port flag still works). It also widens the /api trust fence automatically.
-
Install the plugin, then start normally — without
--host:dsh --profile web --port 3080The bundle patch re-derives the
/apitrust fence from every non-internal IPv4 the host currently has — LAN (192.168.x), Tailscale (100.x), and VPN interfaces — and merges in whateverresolveLanTrustalready computed. So as long as the remote interface is up whendsh webstarts (Tailscale usually autostarts first), LAN and Tailscale IP access need zero extra config: openhttp://<server-ip>:3080orhttp://<tailscale-ip>:3080and sessions/models load.If you prefer NOT to let the plugin take over the bind host (e.g. you want loopback + a port forward), keep the
webserverrow override out of your tree and instead forward a port (socat / rinetd / Tailscale serve) from127.0.0.1:3080, adding the forwarded address totrustedHostsmanually. -
MagicDNS hostnames (e.g.
xxx.tailXXXX.ts.net) — the fence can't discover hostnames, only IP literals, so add your own names if you want to browse by name instead of IP. Patch theweb-runtimerow, whosetrustedHostsfeed into the fence computation (resolveLanTrustmerges them), so your entries stack on top of the auto-discovered IPs:- id: web-runtime config: trustedHosts: - <short-name> # e.g. myhost — MUST be listed separately! - <name>.tailXXXX.ts.net # full domainOr skip file editing entirely with the repeatable CLI flag (same injection path):
dsh --profile web --trusted-host myhost --trusted-host myhost.tailXXXX.ts.net. Use one mechanism or the other — a static list replaces the row's default expression, so it will not merge with--trusted-host.⚠️ The fence compares the
Hostheader literally: a MagicDNS short name (http://myhost:3080) is not the full domain — list the short name on its own line, or every/apicall returns 403 (page shell loads, sessions/models absent). Tailscale / LAN IP literals need no entry here — they stay covered automatically.⚠️ Do not retarget this block at the
connectionrow: patch layers compose by whole-key replacement in application order (bundle layers first, then your profile'scordis.patch.yml), so a plain literal array onconnection.config.trustedHostswould silently replace the bundle's dynamic fence expression — names would work, but the auto-derived LAN/Tailscale IP trust would vanish. If you truly needconnection, copy the full concatenation expression from the plugin's bundle patch and append your literals; never write a plain list there.
Known limitation: privileged API methods
On unmodified harness builds, a small set of sensitive API methods (settings.*, credentials.*, llm.discoverModels) is pinned to loopback regardless of trustedHosts (isTrustedApiRequest(request, []) in packages/client/connection/src/index.ts). From a remote origin those calls return 403: chat/sessions/models still work, but the Settings pages (including the plugin-config cards) and credentials UI show empty/errors. The polyfill cannot change that — it is a product-side policy. A one-line upstream change (isTrustedApiRequest(request, trustedHosts)) makes them follow the deployment's trusted hosts; until then, edit that line locally or manage those settings from http://127.0.0.1:3080.
Verify
curl http://127.0.0.1:3080/ | grep lan-access-polyfill # must match
Then open http://<server-ip>:3080 from another device — sessions and models must load.
Security warning
Binding 0.0.0.0 makes the agent reachable without authentication by anyone on the same network (/api is an origin fence, not a login). On a server with a public IP this means the whole internet. Use only on trusted networks, restrict with a firewall (e.g. ufw allow from 192.168.0.0/16), or expose through Tailscale / an authenticated reverse proxy instead. A TLS reverse proxy also removes the need for this polyfill entirely.
Rollback
- Bundle install:
dsh plugin --profile web remove dsh-web-lan-access - Manual install: delete the
lan-accessinsert block fromcordis.patch.yml; optionally start without--host 0.0.0.0
License
MIT