From ae80eaade0fba58e4e6b2f3023165a641f490e98 Mon Sep 17 00:00:00 2001
From: Neale Swinnerton <neale@sw1nn.com>
Date: Fri, 6 Mar 2026 10:03:17 +0000
Subject: [PATCH] feat(metrics): add bambuddy_build_info metric

Publish a gauge with version, python_version, platform, and
architecture labels at the top of the Prometheus metrics endpoint.
---
 backend/app/api/routes/metrics.py | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/backend/app/api/routes/metrics.py b/backend/app/api/routes/metrics.py
index 3080ed83b..78550e84a 100644
--- a/backend/app/api/routes/metrics.py
+++ b/backend/app/api/routes/metrics.py
@@ -1,9 +1,12 @@
 """Prometheus metrics endpoint for external monitoring."""
 
+import platform
+
 from fastapi import APIRouter, Depends, Header, HTTPException, Response
 from sqlalchemy import func, select
 from sqlalchemy.ext.asyncio import AsyncSession
 
+from backend.app.core.config import APP_VERSION
 from backend.app.core.database import get_db
 from backend.app.models.archive import PrintArchive
 from backend.app.models.print_queue import PrintQueueItem
@@ -77,6 +80,20 @@ async def get_metrics(
 
     lines: list[str] = []
 
+    # =========================================================================
+    # Build info
+    # =========================================================================
+
+    lines.append("# HELP bambuddy_build_info Build and version information")
+    lines.append("# TYPE bambuddy_build_info gauge")
+    build_labels = format_labels(
+        version=APP_VERSION,
+        python_version=platform.python_version(),
+        platform=platform.system(),
+        architecture=platform.machine(),
+    )
+    lines.append(f"bambuddy_build_info{build_labels} 1")
+
     # =========================================================================
     # Printer metrics
     # =========================================================================