diff --git a/.env.example b/.env.example
index c4ff078..9e80cc9 100644
--- a/.env.example
+++ b/.env.example
@@ -12,13 +12,12 @@ LOG_LEVEL=info
 # to ../web/dist relative to the running api bundle.
 # STATIC_DIR=
 
-# Host port exposed by the Portainer stack.
-GASHBOARD_PORT=1337
-
 # ---- Datum gateway (the Umbrel app we're polling) ----
-# The stack joins Umbrel's real Docker network, so use Datum's container name.
-# Do not hard-code Datum's container IP; it can change after reboot.
-DATUM_URL=http://datum_datum_1:21000
+# Umbrel/Portainer stacks cannot reliably resolve Datum's container name.
+# Use Datum's current IP on umbrel_main_network and refresh it if Umbrel
+# recreates the Datum container:
+# docker inspect -f '{{.NetworkSettings.Networks.umbrel_main_network.IPAddress}}' datum_datum_1
+DATUM_URL=http://10.21.0.11:21000
 DATUM_ADMIN_USER=admin
 DATUM_ADMIN_PASSWORD=
 # How often to scrape /clients (ms). Datum updates per-worker hashrate every
diff --git a/README.md b/README.md
index cd522ac..e203dca 100644
--- a/README.md
+++ b/README.md
@@ -46,12 +46,12 @@ Allowlist of npubs is set via `NOSTR_ALLOWED_NPUBS`. Anything else is rejected b
    - Repository URL: `https://git.tx1138.com/lfg2025/gashboard`
    - Compose path: `docker-compose.yml`
    - Add env vars (see `.env.example`)
-   - The stack attaches to the Umbrel network attached to `datum_datum_1`:
+   - Set `DATUM_URL` to Datum's current container IP:
      ```bash
-     docker inspect -f '{{range $name, $_ := .NetworkSettings.Networks}}{{$name}}{{"\n"}}{{end}}' datum_datum_1
+     docker inspect -f '{{.NetworkSettings.Networks.umbrel_main_network.IPAddress}}' datum_datum_1
      ```
-   - On Umbrel this is usually `umbrel_main_network`, which is the compose default.
-   - Leave `DATUM_URL` unset unless you need to override it. The default is `http://datum_datum_1:21000`, which uses Docker DNS and avoids Umbrel's host proxy and stale container IPs.
+   - Use it as `DATUM_URL=http://<that-ip>:21000`.
+   - If Datum/Umbrel recreates the container, refresh this IP in Portainer and redeploy.
 
 4. Open the dashboard, log in with one of the allowed npubs, watch your boards lose at hashing in style.
 
diff --git a/docker-compose.yml b/docker-compose.yml
index 4c4ee26..b0cc00c 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -2,9 +2,9 @@ version: "3.9"
 
 # gashboard — deploy as a Portainer Stack on the same Umbrel host that runs Datum.
 #
-# Attach to Umbrel's real app network so Docker DNS can resolve Datum by
-# container name. This avoids hard-coding Datum's container IP, which can change
-# after reboot and cause ECONNREFUSED.
+# Umbrel's Portainer setup cannot reliably resolve Umbrel app container names
+# from repository stacks. Use host networking and point DATUM_URL at Datum's
+# current container IP on umbrel_main_network.
 
 services:
   gashboard:
@@ -24,9 +24,10 @@ services:
       PORT: "1337"
       LOG_LEVEL: "${LOG_LEVEL:-info}"
       CORS_ORIGIN: "${CORS_ORIGIN:-}"
-      # Reach the Datum gateway container directly over Umbrel's Docker network.
-      # Do not use a hard-coded container IP; it can change after reboot.
-      DATUM_URL: "${DATUM_URL:-http://datum_datum_1:21000}"
+      # Reach the Datum gateway container directly. Refresh this IP if Umbrel
+      # recreates Datum:
+      # docker inspect -f '{{.NetworkSettings.Networks.umbrel_main_network.IPAddress}}' datum_datum_1
+      DATUM_URL: "${DATUM_URL?must be set, e.g. http://10.21.0.11:21000}"
       DATUM_ADMIN_USER: "${DATUM_ADMIN_USER:-admin}"
       DATUM_ADMIN_PASSWORD: "${DATUM_ADMIN_PASSWORD?must be set}"
       DATUM_POLL_INTERVAL_MS: "${DATUM_POLL_INTERVAL_MS:-5000}"
@@ -34,17 +35,10 @@ services:
       NOSTR_ALLOWED_NPUBS: "${NOSTR_ALLOWED_NPUBS?must be set}"
       JWT_SECRET: "${JWT_SECRET?must be set}"
       JWT_TTL_SECONDS: "${JWT_TTL_SECONDS:-86400}"
-    ports:
-      - "${GASHBOARD_PORT:-1337}:1337"
-    networks:
-      - umbrel_main_network
+    network_mode: host
     healthcheck:
       test: ["CMD", "wget", "-qO-", "http://127.0.0.1:1337/healthz"]
       interval: 30s
       timeout: 5s
       retries: 3
       start_period: 15s
-
-networks:
-  umbrel_main_network:
-    external: true