fix(showcase): configure the Fiat checkout panel on the deployed site (runtime embed base)

[aaitor]

Why this matters

The Fiat Checkout tutorial's "See it run" panel on tutorials.nevermined.app still showed "Checkout isn't configured here (NVM_EMBED_BASE_URL is unset)" even after the deploy config was wired up (argocd#628). Visitors couldn't try the card-checkout flow the tutorial teaches. This makes the panel pick up the deployed configuration so it actually runs — pick a trip, pay with a test card, see the booking confirmed.

Root cause

app/t/[slug]/page.tsx is statically prerendered (generateStaticParams, no dynamic/revalidate). It read process.env.NVM_EMBED_BASE_URL in the server component and passed it to the panel as a prop — so the value was captured at next build (where the var is unset → "" → the permanent "not configured" notice). No runtime env on the pod could change an already-prerendered page. The /api/orders route worked only because route handlers are dynamic and read env at request time.

Fix

Read the origin at request time, matching the pattern the live weather panel already uses (app/api/agent reads WEATHER_AGENT_URL in a route handler):

• new app/api/embed-base/route.ts — force-dynamic, returns { embedBase } from NVM_EMBED_BASE_URL at request time.
• FiatRunPanel — fetches /api/embed-base on mount; pick buttons disabled until it loads; on failure falls back to "" (the notice).
• page.tsx — drops the build-time embedBase prop.

Every tutorial page stays SSG; only the tiny config route is dynamic.

Test plan

• npm run build clean; route table shows /t/[slug] ● (SSG) preserved, /api/embed-base ƒ (dynamic).
• Standalone server with NVM_EMBED_BASE_URL=https://embed.nevermined.app → GET /api/embed-base returns {"embedBase":"https://embed.nevermined.app"}; SSG page does not inline the URL (panel fetches it).
• After deploy: panel on tutorials.nevermined.app mounts the checkout iframe (no notice); full 4242 payment → nvm:success → booked.

🤖 Generated with Claude Code

https://claude.ai/code/session_01GYjpDX5ZRMGrpSZ8zAMLg3

[r-marques]

👀 Reviewing

[r-marques]

🤖 Automated PR review — 🟡 Mergeable with nits

Moves the hosted-checkout origin off the SSG page and behind a dynamic route handler the panel fetches at mount. The diagnosis is right and is the non-obvious part: /t/[slug] is statically generated, so process.env.NVM_EMBED_BASE_URL read there is frozen at next build — unset at build time means a permanent "not configured" notice no amount of redeploying fixes. No blockers.

What I verified

• Diff range origin/main...HEAD — 3 files, +39/−12, head c16411f85.
• No panel — a 39-line diff, verified directly. Saying so rather than implying coverage I do not have.
• The new null state does not open a fail-open window. The nvm:success listener is if (!embedOrigin || e.origin !== embedOrigin) return;, and embedOrigin derives to "" while embedBase is null — so during the fetch, every inbound postMessage is rejected. pick() is guarded the same way.
• A malformed NVM_EMBED_BASE_URL also fails closed — new URL(embedBase).origin is wrapped in try/catch returning "", so an operator typo (a host with no scheme, say) yields the notice rather than an unhandled TypeError in render. I went looking for that crash specifically; it is not there.
• force-dynamic is correct for this version. next@^15.5.25, where route handlers are already dynamic by default — so the comment's "handlers are always dynamic" is accurate here and the export is defence in depth, not a contradiction.

One thing worth reporting back across repos. Reviewing argocd#628 earlier today I raised a should-fix that argocd cannot check the claim "org key stays server-side", since the guard lives in this repo. It does hold: NVM_ORDER_API_KEY is read only in showcase/app/api/orders/route.ts — a route handler — and sent as Authorization: Bearer. FiatRunPanel.tsx is "use client" and mentions the name only in a comment and an error string; it never reads it from process.env, and the unprefixed name means Next would not inline it regardless. That finding can be considered answered.

Verdict: 🟡 Mergeable with nits — 0 blockers, 1 should-fix, 2 nits. The should-fix is a missing timeout whose failure mode is a permanently inert panel; the pattern to copy is already in the same file.

🧭 Inline comments (3)

Each is posted on its line in Files changed.

• 🟡 SHOULD FIX — This fetch has no timeout, and a hang disables every button permanently — showcase/components/FiatRunPanel.tsx:58
• 💡 NIT — Confirm the response is not cacheable by the CDN in front of the site — showcase/app/api/embed-base/route.ts:14
• 💡 NIT — Disabled-while-loading has no affordance saying so — showcase/components/FiatRunPanel.tsx:207

[r-marques]

🟡 Approved with comments — no blockers; 1 should-fix, 2 nit(s) left inline.

Inline review: #75 (review)