Fix shell-dashboard shell links by plumbing NEXT_PUBLIC_SHELL_URL through build

The shell-dashboard app baked http://localhost:3000 into every demo and code link because NEXT_PUBLIC_SHELL_URL was never provided at build time and the source defaulted to localhost. Next.js inlines NEXT_PUBLIC_* at next build, so setting the value on Railway at runtime does nothing.

Fix: remove the silent localhost fallback, pass NEXT_PUBLIC_SHELL_URL as a Docker build arg from showcase_deploy.yml, and fail loudly if it's unset at build so this can't regress silently.

Author: jpr5

.github/workflows/showcase_deploy.yml

@@ -175,7 +175,7 @@ jobs:
             {"dispatch_name":"starter-strands","filter_key":"starter_strands","context":"showcase/starters/strands","image":"showcase-starter-strands","railway_id":"06db2bb8-e15d-4c6a-97ad-e14777c92d9f","timeout":15,"lfs":false,"build_args":"","dockerfile":"","health_path":"/api/health"},
             {"dispatch_name":"aimock","filter_key":"aimock","context":"showcase/aimock","image":"showcase-aimock","railway_id":"0fa0435d-8a66-46f0-84fd-e4250b580013","timeout":5,"lfs":false,"build_args":"","dockerfile":"","health_path":"/health"},
             {"dispatch_name":"shell-dojo","filter_key":"shell_dojo","context":"showcase/shell-dojo","image":"showcase-shell-dojo","railway_id":"7ad1ece7-2228-49cd-8a78-bddf30322907","timeout":10,"lfs":false,"build_args":"","dockerfile":"","health_path":"/"},
-            {"dispatch_name":"shell-dashboard","filter_key":"shell_dashboard","context":".","image":"showcase-shell-dashboard","railway_id":"4d5dfd74-be61-40b2-8564-b53b7dd4c15b","timeout":10,"lfs":true,"build_args_sha":"${{ github.sha }}","build_args_branch":"${{ github.ref_name }}","dockerfile":"showcase/shell-dashboard/Dockerfile","health_path":"/"},
+            {"dispatch_name":"shell-dashboard","filter_key":"shell_dashboard","context":".","image":"showcase-shell-dashboard","railway_id":"4d5dfd74-be61-40b2-8564-b53b7dd4c15b","timeout":10,"lfs":true,"build_args_sha":"${{ github.sha }}","build_args_branch":"${{ github.ref_name }}","build_args_shell_url":"https://showcase.copilotkit.ai","dockerfile":"showcase/shell-dashboard/Dockerfile","health_path":"/"},
             {"dispatch_name":"shell-docs","filter_key":"shell_docs","context":".","image":"showcase-shell-docs","railway_id":"7badfb8d-4228-414c-9145-b4026803714f","timeout":10,"lfs":true,"build_args_sha":"${{ github.sha }}","build_args_branch":"${{ github.ref_name }}","dockerfile":"showcase/shell-docs/Dockerfile","health_path":"/"}
           ]'
 
@@ -278,6 +278,16 @@ jobs:
             ARGS="COMMIT_SHA=${{ matrix.service.build_args_sha }}"
             ARGS="${ARGS}"$'\n'"BRANCH=${{ matrix.service.build_args_branch }}"
           fi
+          # shell-dashboard needs NEXT_PUBLIC_SHELL_URL at build time —
+          # Next.js inlines NEXT_PUBLIC_* during `next build`, so the
+          # Railway runtime env var alone can't rescue a bad build.
+          if [ -n "${{ matrix.service.build_args_shell_url }}" ]; then
+            if [ -n "$ARGS" ]; then
+              ARGS="${ARGS}"$'\n'"NEXT_PUBLIC_SHELL_URL=${{ matrix.service.build_args_shell_url }}"
+            else
+              ARGS="NEXT_PUBLIC_SHELL_URL=${{ matrix.service.build_args_shell_url }}"
+            fi
+          fi
           # Use delimiter to safely pass multiline value
           echo "args<<BUILDARGS_EOF" >> $GITHUB_OUTPUT
           echo "$ARGS" >> $GITHUB_OUTPUT

showcase/shell-dashboard/Dockerfile

@@ -24,6 +24,11 @@ COPY showcase/shell-dashboard/ ./shell-dashboard/
 ENV NEXT_PUBLIC_COMMIT_SHA=${COMMIT_SHA}
 ENV NEXT_PUBLIC_BRANCH=${BRANCH}
 
+# Shell URL is inlined by Next.js at build time (NEXT_PUBLIC_*). Must be
+# provided as a build arg — a runtime env var on Railway is too late.
+ARG NEXT_PUBLIC_SHELL_URL
+ENV NEXT_PUBLIC_SHELL_URL=${NEXT_PUBLIC_SHELL_URL}
+
 # Generate registry + docs status + demo content, then build Next.js
 RUN cd scripts && node node_modules/tsx/dist/cli.mjs generate-registry.ts \
     && node node_modules/tsx/dist/cli.mjs probe-docs.ts \

showcase/shell-dashboard/src/components/feature-grid.tsx

@@ -16,6 +16,23 @@ import {
 } from "@/lib/status";
 import { getDocsStatus } from "@/lib/docs-status";
 
+// Read NEXT_PUBLIC_SHELL_URL at module scope so a missing value fails the
+// build (`next build` evaluates top-level module code for this server
+// component). Previously this fell back silently to http://localhost:3000
+// when the env var wasn't set, which baked localhost into every demo/code
+// link in the deployed dashboard because Next.js inlines NEXT_PUBLIC_* at
+// build time and a runtime env var can't rescue a bad build.
+function requireShellUrl(): string {
+  const url = process.env.NEXT_PUBLIC_SHELL_URL;
+  if (!url) {
+    throw new Error(
+      "NEXT_PUBLIC_SHELL_URL must be set at build time for shell-dashboard",
+    );
+  }
+  return url;
+}
+const SHELL_URL: string = requireShellUrl();
+
 export interface CellContext {
   integration: Integration;
   feature: Feature;
@@ -112,7 +129,7 @@ export function FeatureGrid({
   renderCell: CellRenderer;
   minColWidth?: number;
 }) {
-  const shellUrl = process.env.NEXT_PUBLIC_SHELL_URL || "http://localhost:3000";
+  const shellUrl = SHELL_URL;
   const integrations = getIntegrations();
   const features = getFeatures();
   const categories = getFeatureCategories();