diff --git a/kiwi_simple_metrics/main.py b/kiwi_simple_metrics/main.py
index 6301fea..18b2656 100644
--- a/kiwi_simple_metrics/main.py
+++ b/kiwi_simple_metrics/main.py
@@ -6,14 +6,11 @@ from . import metrics
 from .settings import SETTINGS
 
 
-def handle_report() -> None:
+def run_metrics(*_metrics: metrics.Metric) -> None:
+    reports = (metric() for metric in _metrics)
+
     # create single report from metrics
-    report = metrics.Report.summary(
-        metrics.cpu(),
-        metrics.memory(),
-        metrics.disk(),
-        metrics.external(),
-    )
+    report = metrics.Report.summary(*reports)
 
     # maybe print this to stdout
     if SETTINGS.log.enabled:
@@ -23,18 +20,24 @@ def handle_report() -> None:
     report.push_webhook()
 
 
-async def run_metrics() -> None:
+async def async_main() -> None:
     loop = asyncio.get_running_loop()
 
     while True:
         await asyncio.gather(
             asyncio.sleep(SETTINGS.interval),
-            loop.run_in_executor(None, handle_report),
+            loop.run_in_executor(
+                None, run_metrics,
+                metrics.cpu,
+                metrics.memory,
+                metrics.disk,
+                metrics.external,
+            ),
         )
 
 
 def main() -> None:
-    asyncio.run(run_metrics())
+    asyncio.run(async_main())
 
 
 if __name__ == "__main__":
diff --git a/kiwi_simple_metrics/metrics/__init__.py b/kiwi_simple_metrics/metrics/__init__.py
index cf1a0c0..8a2a250 100644
--- a/kiwi_simple_metrics/metrics/__init__.py
+++ b/kiwi_simple_metrics/metrics/__init__.py
@@ -1,11 +1,16 @@
+from typing import Callable, TypeAlias
+
 from ._report import Report
 from .cpu import cpu
 from .disk import disk
 from .external import external
 from .memory import memory
 
+Metric: TypeAlias = Callable[[], Report | None]
+
 __all__ = [
     "Report",
+    "Metric",
 
     "cpu",
     "disk",