From 9962191bc5676858310267785c1586664580601b Mon Sep 17 00:00:00 2001
From: Simon Gurcke <simon@gurcke.de>
Date: Sat, 29 Nov 2025 19:25:39 +1000
Subject: [PATCH 1/2] Capture CPU/memory metrics

---
 src/common/client.ts    |  2 ++
 src/common/resources.ts | 35 +++++++++++++++++++++++++++++++++++
 src/common/types.ts     |  4 ++++
 3 files changed, 41 insertions(+)
 create mode 100644 src/common/resources.ts

diff --git a/src/common/client.ts b/src/common/client.ts
index 631ac71..4090ec1 100644
--- a/src/common/client.ts
+++ b/src/common/client.ts
@@ -6,6 +6,7 @@ import { Logger, getLogger } from "./logging.js";
 import { isValidClientId, isValidEnv } from "./paramValidation.js";
 import RequestCounter from "./requestCounter.js";
 import RequestLogger from "./requestLogger.js";
+import { getCpuMemoryUsage } from "./resources.js";
 import ServerErrorCounter from "./serverErrorCounter.js";
 import {
   ApitallyConfig,
@@ -225,6 +226,7 @@ export class ApitallyClient {
         this.validationErrorCounter.getAndResetValidationErrors(),
       server_errors: this.serverErrorCounter.getAndResetServerErrors(),
       consumers: this.consumerRegistry.getAndResetUpdatedConsumers(),
+      resources: getCpuMemoryUsage(),
     };
     this.syncDataQueue.push(newPayload);
 
diff --git a/src/common/resources.ts b/src/common/resources.ts
new file mode 100644
index 0000000..a2f22a0
--- /dev/null
+++ b/src/common/resources.ts
@@ -0,0 +1,35 @@
+let lastCpuUsage: { user: number; system: number } | null = null;
+let lastCpuTime: number | null = null;
+
+export function getCpuMemoryUsage() {
+  const currentCpuUsage = process.cpuUsage();
+  const currentTime = Date.now();
+  const memoryRss = process.memoryUsage().rss;
+
+  let cpuPercent = null;
+
+  if (lastCpuUsage !== null && lastCpuTime !== null) {
+    // Calculate elapsed time in microseconds
+    const elapsedTime = (currentTime - lastCpuTime) * 1000;
+
+    // Calculate CPU time used (user + system) in microseconds
+    const cpuTime =
+      currentCpuUsage.user -
+      lastCpuUsage.user +
+      (currentCpuUsage.system - lastCpuUsage.system);
+
+    // Calculate percentage
+    cpuPercent = (cpuTime / elapsedTime) * 100;
+  }
+
+  // Update last values for next call
+  lastCpuUsage = currentCpuUsage;
+  lastCpuTime = currentTime;
+
+  return cpuPercent !== null
+    ? {
+        cpu_percent: cpuPercent,
+        memory_rss: memoryRss,
+      }
+    : null;
+}
diff --git a/src/common/types.ts b/src/common/types.ts
index 2eb837c..94b88e8 100644
--- a/src/common/types.ts
+++ b/src/common/types.ts
@@ -94,4 +94,8 @@ export type SyncPayload = {
   validation_errors: Array<ValidationErrorsItem>;
   server_errors: Array<ServerErrorsItem>;
   consumers: Array<ConsumerItem>;
+  resources: {
+    cpu_percent: number;
+    memory_rss: number;
+  } | null;
 };

From 676770abd9ac2c8d5165840e3d06464e4a69a9ee Mon Sep 17 00:00:00 2001
From: Simon Gurcke <simon@gurcke.de>
Date: Sun, 30 Nov 2025 22:41:58 +1000
Subject: [PATCH 2/2] Fix

---
 src/common/resources.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/common/resources.ts b/src/common/resources.ts
index a2f22a0..3a36eab 100644
--- a/src/common/resources.ts
+++ b/src/common/resources.ts
@@ -3,7 +3,7 @@ let lastCpuTime: number | null = null;
 
 export function getCpuMemoryUsage() {
   const currentCpuUsage = process.cpuUsage();
-  const currentTime = Date.now();
+  const currentTime = performance.now();
   const memoryRss = process.memoryUsage().rss;
 
   let cpuPercent = null;