diff --git a/docker-dev/docker-compose.yml b/docker-dev/docker-compose.yml
index d19fe9bd..af4cd50e 100644
--- a/docker-dev/docker-compose.yml
+++ b/docker-dev/docker-compose.yml
@@ -47,6 +47,29 @@
 
 name: otopcua-dev
 
+# ── Shared secret-replication env (all six host nodes) ──────────────────────────
+# Akka peer-to-peer clustered secret replication rides the existing `otopcua` Akka
+# mesh (DistributedPubSub topic `zb-mom-ww-secrets`) across all six host nodes. Two
+# hard requirements are wired here, identically, on every node:
+#   1. Secrets__Replication__Enabled=true  → SecretsRegistration.AddOtOpcUaSecrets
+#      switches from plain AddZbSecrets to AddZbSecretsAkkaReplication + the eager
+#      SecretReplicationStarter hosted service, so every node joins anti-entropy.
+#   2. ZB_SECRETS_MASTER_KEY  → the ONE shared 32-byte base64 KEK. Every node MUST
+#      carry the SAME key or peers fail closed decrypting each other's rows
+#      (kek_id mismatch). appsettings.json binds Secrets:MasterKey:Source=Environment
+#      / EnvVarName=ZB_SECRETS_MASTER_KEY, so this env var IS the KEK on every node.
+# The KEK below is a committed DEV-ONLY default (matches the rig's zero-operator-step
+# philosophy, like the committed dev SQL password). Override for a fresh key with:
+#   OTOPCUA_SECRETS_KEK=$(openssl rand -base64 32) docker compose ... up -d
+# NEVER reuse this key outside this local dev rig.
+# AnnounceInterval is shortened to 5s (default 30s) so anti-entropy convergence is
+# observable quickly during dev exercise. Each node keeps its own local SQLite store
+# (Secrets:SqlitePath=otopcua-secrets.db, per-container); replication syncs them.
+x-secrets-env: &secrets-env
+  Secrets__Replication__Enabled: "true"
+  Secrets__Replication__AnnounceInterval: "00:00:05"
+  ZB_SECRETS_MASTER_KEY: "${OTOPCUA_SECRETS_KEK:-ZYGhIX0luS/XsevpCB2W18jYHMcqO6AjM9oXy+T6Zp4=}"
+
 services:
 
   sql:
@@ -145,6 +168,7 @@ services:
       sql: { condition: service_healthy }
       migrator: { condition: service_completed_successfully }
     environment:
+      <<: *secrets-env
       OTOPCUA_ROLES: "admin,driver"
       ASPNETCORE_URLS: "http://+:9000"
       ConnectionStrings__ConfigDb: "Server=sql,1433;Database=OtOpcUa;User Id=sa;Password=OtOpcUa!Dev123;TrustServerCertificate=True;"
@@ -210,6 +234,7 @@ services:
       central-1: { condition: service_started }
       migrator: { condition: service_completed_successfully }
     environment:
+      <<: *secrets-env
       OTOPCUA_ROLES: "admin,driver"
       ASPNETCORE_URLS: "http://+:9000"
       ConnectionStrings__ConfigDb: "Server=sql,1433;Database=OtOpcUa;User Id=sa;Password=OtOpcUa!Dev123;TrustServerCertificate=True;"
@@ -280,6 +305,7 @@ services:
       Cluster__PublicHostname: "site-a-1"
       Cluster__SeedNodes__0: "akka.tcp://otopcua@central-1:4053"
       Cluster__Roles__0: "driver"
+      <<: *secrets-env
       # Quiet EF/AspNetCore SQL flood — see central-1 (Serilog override). mem_limit/
       # mem_reservation are inherited from the *otopcua-host anchor.
       Serilog__MinimumLevel__Override__Microsoft.EntityFrameworkCore: "Warning"
@@ -304,6 +330,7 @@ services:
       Cluster__PublicHostname: "site-a-2"
       Cluster__SeedNodes__0: "akka.tcp://otopcua@central-1:4053"
       Cluster__Roles__0: "driver"
+      <<: *secrets-env
       Serilog__MinimumLevel__Override__Microsoft.EntityFrameworkCore: "Warning"
       Serilog__MinimumLevel__Override__Microsoft.AspNetCore: "Warning"
       GALAXY_MXGW_API_KEY: "${GALAXY_MXGW_API_KEY:-mxgw_otopcua2_GI7-tNozYE6cXGUSgEzL3AHDV7bYcYIHdMwKYgyHdX4}"
@@ -326,6 +353,7 @@ services:
       Cluster__PublicHostname: "site-b-1"
       Cluster__SeedNodes__0: "akka.tcp://otopcua@central-1:4053"
       Cluster__Roles__0: "driver"
+      <<: *secrets-env
       Serilog__MinimumLevel__Override__Microsoft.EntityFrameworkCore: "Warning"
       Serilog__MinimumLevel__Override__Microsoft.AspNetCore: "Warning"
       GALAXY_MXGW_API_KEY: "${GALAXY_MXGW_API_KEY:-mxgw_otopcua2_GI7-tNozYE6cXGUSgEzL3AHDV7bYcYIHdMwKYgyHdX4}"
@@ -346,6 +374,7 @@ services:
       Cluster__PublicHostname: "site-b-2"
       Cluster__SeedNodes__0: "akka.tcp://otopcua@central-1:4053"
       Cluster__Roles__0: "driver"
+      <<: *secrets-env
       Serilog__MinimumLevel__Override__Microsoft.EntityFrameworkCore: "Warning"
       Serilog__MinimumLevel__Override__Microsoft.AspNetCore: "Warning"
       GALAXY_MXGW_API_KEY: "${GALAXY_MXGW_API_KEY:-mxgw_otopcua2_GI7-tNozYE6cXGUSgEzL3AHDV7bYcYIHdMwKYgyHdX4}"