feat: add Prometheus metrics endpoint

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/api/metrics/route.ts

@@ -0,0 +1,38 @@
+import { NextResponse } from 'next/server';
+import client from 'prom-client';
+
+// Create a Registry to register the metrics
+const register = new client.Registry();
+
+// Add default metrics (CPU, memory, etc.)
+client.collectDefaultMetrics({ register });
+
+// Custom metrics
+const httpRequestsTotal = new client.Counter({
+  name: 'http_requests_total',
+  help: 'Total number of HTTP requests',
+  labelNames: ['method', 'path', 'status'],
+  registers: [register],
+});
+
+const httpRequestDuration = new client.Histogram({
+  name: 'http_request_duration_seconds',
+  help: 'Duration of HTTP requests in seconds',
+  labelNames: ['method', 'path'],
+  buckets: [0.1, 0.3, 0.5, 0.7, 1, 3, 5, 7, 10],
+  registers: [register],
+});
+
+export async function GET() {
+  try {
+    const metrics = await register.metrics();
+    return new NextResponse(metrics, {
+      status: 200,
+      headers: {
+        'Content-Type': register.contentType,
+      },
+    });
+  } catch (error) {
+    return NextResponse.json({ error: 'Failed to get metrics' }, { status: 500 });
+  }
+}

package-lock.json

@@ -16,6 +16,7 @@
         "next": "14.2.4",
         "next-auth": "^4.24.7",
         "nodemailer": "^7.0.10",
+        "prom-client": "^15.1.3",
         "react": "18.2.0",
         "react-dom": "18.2.0",
         "react-hook-form": "^7.66.0",
@@ -511,6 +512,15 @@
         "node": ">=12.4.0"
       }
     },
+    "node_modules/@opentelemetry/api": {
+      "version": "1.9.0",
+      "resolved": "https://registry.npmjs.org/@opentelemetry/api/-/api-1.9.0.tgz",
+      "integrity": "sha512-3giAOQvZiH5F9bMlMiv8+GSPMeqg0dbaeo58/0SlA9sxSqZhnUtxzX9/2FzyhS9sWQf5S0GJE0AKBrFqjpeYcg==",
+      "license": "Apache-2.0",
+      "engines": {
+        "node": ">=8.0.0"
+      }
+    },
     "node_modules/@panva/hkdf": {
       "version": "1.2.1",
       "resolved": "https://registry.npmjs.org/@panva/hkdf/-/hkdf-1.2.1.tgz",
@@ -1556,6 +1566,12 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
+    "node_modules/bintrees": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/bintrees/-/bintrees-1.0.2.tgz",
+      "integrity": "sha512-VOMgTMwjAaUG580SXn3LacVgjurrbMme7ZZNYGSSV7mmtY6QQRh0Eg3pwIcntQ77DErK1L0NxkbetjcoXzVwKw==",
+      "license": "MIT"
+    },
     "node_modules/bootstrap": {
       "version": "5.3.8",
       "resolved": "https://registry.npmjs.org/bootstrap/-/bootstrap-5.3.8.tgz",
@@ -5128,6 +5144,19 @@
       "integrity": "sha512-WuxUnVtlWL1OfZFQFuqvnvs6MiAGk9UNsBostyBOB0Is9wb5uRESevA6rnl/rkksXaGX3GzZhPup5d6Vp1nFew==",
       "license": "MIT"
     },
+    "node_modules/prom-client": {
+      "version": "15.1.3",
+      "resolved": "https://registry.npmjs.org/prom-client/-/prom-client-15.1.3.tgz",
+      "integrity": "sha512-6ZiOBfCywsD4k1BN9IX0uZhF+tJkV8q8llP64G5Hajs4JOeVLPCwpPVcpXy3BwYiUGgyJzsJJQeOIv7+hDSq8g==",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "@opentelemetry/api": "^1.4.0",
+        "tdigest": "^0.1.1"
+      },
+      "engines": {
+        "node": "^16 || ^18 || >=20"
+      }
+    },
     "node_modules/prop-types": {
       "version": "15.8.1",
       "resolved": "https://registry.npmjs.org/prop-types/-/prop-types-15.8.1.tgz",
@@ -6154,6 +6183,15 @@
         "node": ">= 6"
       }
     },
+    "node_modules/tdigest": {
+      "version": "0.1.2",
+      "resolved": "https://registry.npmjs.org/tdigest/-/tdigest-0.1.2.tgz",
+      "integrity": "sha512-+G0LLgjjo9BZX2MfdvPfH+MKLCrxlXSYec5DaPYP1fe6Iyhf0/fSmJ0bFiZ1F8BT6cGXl2LpltQptzjXKWEkKA==",
+      "license": "MIT",
+      "dependencies": {
+        "bintrees": "1.0.2"
+      }
+    },
     "node_modules/text-table": {
       "version": "0.2.0",
       "resolved": "https://registry.npmjs.org/text-table/-/text-table-0.2.0.tgz",

package.json

@@ -19,6 +19,7 @@
     "next": "14.2.4",
     "next-auth": "^4.24.7",
     "nodemailer": "^7.0.10",
+    "prom-client": "^15.1.3",
     "react": "18.2.0",
     "react-dom": "18.2.0",
     "react-hook-form": "^7.66.0",