diff --git a/Dockerfile b/Dockerfile
index e39d565..5b2de63 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -20,10 +20,8 @@ ENV NEXT_TELEMETRY_DISABLED=1
 # Build-time configuration — forwarded into `next build` so server-side
 # fetches during static generation hit the correct API host.
 ARG TRACKER_API_BASE
-ARG NEXT_PUBLIC_TRACKER_API_BASE
 ARG NEXT_PUBLIC_SITE_URL
 ENV TRACKER_API_BASE=$TRACKER_API_BASE
-ENV NEXT_PUBLIC_TRACKER_API_BASE=$NEXT_PUBLIC_TRACKER_API_BASE
 ENV NEXT_PUBLIC_SITE_URL=$NEXT_PUBLIC_SITE_URL
 
 RUN pnpm run build
diff --git a/README.md b/README.md
index 41879f5..1900c1d 100644
--- a/README.md
+++ b/README.md
@@ -68,7 +68,7 @@ Required in production:
 | Variable | Purpose | Notes |
 |----------|---------|-------|
 | `NEXT_PUBLIC_SITE_URL` | Canonical/OG/sitemap base URL | e.g. `https://buildcanada.com`. Used by `layout.tsx`, `sitemap.ts`, `robots.ts`, `lib/api/config.ts`, and JSON-LD. |
-| `NEXT_PUBLIC_TRACKER_API_BASE` | Backend host for `/tracker/api/*` rewrites | Set to wherever the Outcomes Tracker API is served. Falls back to `https://www.buildcanada.com`, which will loop after cutover. |
+| `TRACKER_API_BASE` | Backend host for `/tracker/api/*` rewrites and server-side fetches | Set to wherever the Outcomes Tracker API is served. Falls back to `https://www.buildcanada.com`, which will loop after cutover. Server-only — never exposed to the browser. |
 | `YORK_FACTORY_API_URL` | York Factory CMS base URL | Defaults to `https://yorkfactory.buildcanada.com/api/v1`. Override per environment. |
 | `LUMA_API_KEY` | Luma events list (`/api/events`) | Without this the homepage events list silently returns empty. |
 
@@ -79,7 +79,6 @@ Recommended:
 | `NEXT_PUBLIC_POSTHOG_TOKEN` | PostHog analytics + client-side exception capture (`error.tsx` boundaries report here). |
 | `NEXT_PUBLIC_POSTHOG_HOST` | PostHog UI host. Defaults to `https://us.i.posthog.com`. |
 | `NEXT_PUBLIC_GA_MEASUREMENT_ID` | Google Analytics. Loader is conditional — omit to disable. |
-| `TRACKER_API_BASE` | Server-only override for tracker API base (read in `lib/tracker-api.ts` when no public var is set). |
 
 ## Deployment notes
 
diff --git a/next.config.ts b/next.config.ts
index 97f0a3b..2db294b 100644
--- a/next.config.ts
+++ b/next.config.ts
@@ -21,6 +21,31 @@ const nextConfig: NextConfig = {
     ];
   },
   async rewrites() {
+    const trackerBase = process.env.TRACKER_API_BASE;
+
+    // Default (buildcanada.com): Rails API is mounted under /tracker, paths
+    // pass through unchanged. Standalone host (e.g. nelson deploy): commitments
+    // and departments live at the root (strip /tracker/api/v1), while
+    // dashboard/burndown stay under /api (strip /tracker only). Mirrors the
+    // server-side mapping in src/lib/tracker-api.ts.
+    const trackerRewrites = trackerBase
+      ? [
+          {
+            source: "/tracker/api/v1/:path*",
+            destination: `${trackerBase}/:path*`,
+          },
+          {
+            source: "/tracker/api/:path*",
+            destination: `${trackerBase}/api/:path*`,
+          },
+        ]
+      : [
+          {
+            source: "/tracker/api/:path*",
+            destination: `https://www.buildcanada.com/tracker/api/:path*`,
+          },
+        ];
+
     return [
       {
         source: "/ph/static/:path*",
@@ -34,10 +59,7 @@ const nextConfig: NextConfig = {
         source: "/ph/decide",
         destination: "https://us.i.posthog.com/decide",
       },
-      {
-        source: "/tracker/api/:path*",
-        destination: `${process.env.NEXT_PUBLIC_TRACKER_API_BASE || "https://www.buildcanada.com"}/tracker/api/:path*`,
-      },
+      ...trackerRewrites,
     ];
   },
   // Required to support PostHog trailing slash API requests
diff --git a/src/lib/tracker-api.ts b/src/lib/tracker-api.ts
index b06da8d..c9b65d4 100644
--- a/src/lib/tracker-api.ts
+++ b/src/lib/tracker-api.ts
@@ -11,8 +11,7 @@
 //    /departments.json) while dashboard/burndown still live under /api/*. We
 //    strip the /api/v1 prefix on those two endpoints and skip the /tracker
 //    prepend.
-const EXPLICIT_BASE =
-  process.env.TRACKER_API_BASE || process.env.NEXT_PUBLIC_TRACKER_API_BASE;
+const EXPLICIT_BASE = process.env.TRACKER_API_BASE;
 
 const API_BASE = EXPLICIT_BASE || "https://www.buildcanada.com";