From 9d2f896ae8d2e4e2df99307221c0f19e6b38dd37 Mon Sep 17 00:00:00 2001
From: Fabiano Cruz <fabianoc@acm.org>
Date: Wed, 24 Jun 2026 11:23:17 -0300
Subject: [PATCH] feat(x402-demo): public deploy config + PORT from env

Dockerfile + railway.json to ship the x402 paywall demo ($0.001 USDC, Base Sepolia) as a public CodeSpar example API; server now reads process.env.PORT for Railway.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 examples/x402-demo/Dockerfile   | 18 ++++++++++++++++++
 examples/x402-demo/railway.json | 14 ++++++++++++++
 examples/x402-demo/server.ts    |  2 +-
 3 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 examples/x402-demo/Dockerfile
 create mode 100644 examples/x402-demo/railway.json

diff --git a/examples/x402-demo/Dockerfile b/examples/x402-demo/Dockerfile
new file mode 100644
index 00000000..f4cd477f
--- /dev/null
+++ b/examples/x402-demo/Dockerfile
@@ -0,0 +1,18 @@
+# x402 demo server — public 402 paywall ($0.001 USDC on Base Sepolia).
+# Deployed as a CodeSpar example API so agents can pay a real 402 resource.
+# Env (set in Railway, NOT baked in): SERVER_ADDRESS (payee 0x), FACILITATOR_URL.
+# Do NOT copy .env into the image — it holds the example CLIENT_PRIVATE_KEY.
+FROM node:22-slim
+WORKDIR /app
+
+COPY package.json ./
+# Full install (not --omit=dev): the server runs via `tsx`, a devDependency.
+RUN npm install --no-audit --no-fund
+
+COPY server.ts ./
+
+# Railway injects PORT; the server reads process.env.PORT (fallback 4021).
+ENV PORT=4021
+EXPOSE 4021
+
+CMD ["npx", "tsx", "server.ts"]
diff --git a/examples/x402-demo/railway.json b/examples/x402-demo/railway.json
new file mode 100644
index 00000000..da19d9f5
--- /dev/null
+++ b/examples/x402-demo/railway.json
@@ -0,0 +1,14 @@
+{
+  "$schema": "https://railway.com/railway.schema.json",
+  "build": {
+    "builder": "DOCKERFILE",
+    "dockerfilePath": "Dockerfile",
+    "watchPatterns": ["examples/x402-demo/**"]
+  },
+  "deploy": {
+    "healthcheckPath": "/api/health",
+    "healthcheckTimeout": 10,
+    "restartPolicyType": "ON_FAILURE",
+    "restartPolicyMaxRetries": 3
+  }
+}
diff --git a/examples/x402-demo/server.ts b/examples/x402-demo/server.ts
index 69731378..95c9eb98 100644
--- a/examples/x402-demo/server.ts
+++ b/examples/x402-demo/server.ts
@@ -88,7 +88,7 @@ app.get("/api/premium-analysis", (_req, res) => {
   });
 });
 
-const PORT = 4021;
+const PORT = Number(process.env.PORT) || 4021;
 app.listen(PORT, () => {
   console.log(`\n  x402 Demo Server running on http://localhost:${PORT}`);
   console.log(`  Network: Base Sepolia (eip155:84532)`);