diff --git a/nix/host-modules/otel.nix b/nix/host-modules/otel.nix
index 19a44f6a..2b6c32a1 100644
--- a/nix/host-modules/otel.nix
+++ b/nix/host-modules/otel.nix
@@ -489,6 +489,18 @@ in
             };
           };
 
+          # Converts any DELTA-temporality counter to CUMULATIVE before it
+          # leaves this hive. `hive-metric` counters are delta by default
+          # (agent ergonomics — see its own docs); the swarm's store
+          # (VictoriaMetrics) has no `deltatocumulative` of its own and
+          # official guidance is to feed it cumulative. Default config
+          # (`{ }`) is a no-op passthrough for anything already cumulative
+          # — Claude Code's own export, `hostmetrics`, and any Prometheus
+          # scrape all stay exactly as they were. Verified against the
+          # collector binary rather than assumed: an empty config validates
+          # clean, an invalid key is rejected (`otelcol-contrib validate`).
+          processors.deltatocumulative = { };
+
           service.pipelines.metrics = {
             # EXTENDED, not replaced. Assigning here instead of appending
             # would drop `otlp` — the hive would stop receiving from its
@@ -512,8 +524,12 @@ in
             # samples scraped from a target both arrive at the store with
             # the identity of the machine that collected them, and a
             # reading is only comparable across hives once it says where
-            # it came from.
-            processors = [ "resourcedetection" ];
+            # it came from. `deltatocumulative` first, so a delta counter is
+            # already fixed up by the time it picks up its host identity.
+            processors = [
+              "deltatocumulative"
+              "resourcedetection"
+            ];
             exporters = [ swarmName ];
           };
         }