diff --git a/2026/2026-09-05--taler-apt-src-ubuntu.md b/2026/2026-09-05--taler-apt-src-ubuntu.md
new file mode 100644
index 0000000..04b10f2
--- /dev/null
+++ b/2026/2026-09-05--taler-apt-src-ubuntu.md
@@ -0,0 +1,24 @@
+# taler apt-src ubuntu (noble) on koopa
+
+**2026-09-05** — Freigabe: create Ubuntu track next to existing trixie apt-src pods.
+
+## container
+
+| name | base | suite | image |
+|------|------|-------|-------|
+| `koopa-taler-deploy-test-apt-src-ubuntu` | `ubuntu:24.04` | `noble` @ `deb.taler.net/apt/ubuntu` | `localhost/…:setup` after commit |
+
+ensure: `~/src/taler-monitoring/host-agent/ensure-apt-deploy-test-containers.sh ubuntu`  
+(branch `llm-lightweight-monitoring` / tip after `v1.27.0`)
+
+## verify
+
+```bash
+podman ps -a --filter name=koopa-taler-deploy-test-apt-src-ubuntu
+ANSIBLE_SMOKE_PODMAN=1 ANSIBLE_SMOKE_REQUIRE_UBUNTU=1 \
+  ./taler-monitoring.sh ansible-smoke
+```
+
+## notes
+
+Debian trixie×4 unchanged. Spam mailbox secrets / durable monitord still separate Freigabe items.
diff --git a/configs/lab-local/goa-regio-ng-koopa.yml b/configs/lab-local/goa-regio-ng-koopa.yml
index 00450d8..04d502e 100644
--- a/configs/lab-local/goa-regio-ng-koopa.yml
+++ b/configs/lab-local/goa-regio-ng-koopa.yml
@@ -53,7 +53,8 @@ regional_currency:
       regional_currency_common_amounts: "GOA:10 GOA:20 GOA:50 GOA:100 GOA:200 GOA:1000"
       regional_currency_static_coins_file: goa-exchange-coins.conf
       regional_currency_coin_withdraw_duration: 7 days
-      regional_currency_default_debt_limit: "GOA:4503599627370496"
+      # Must stay < 2^52 (libeufin amount overflow on withdraw confirm).
+      regional_currency_default_debt_limit: "GOA:1000000000000"
 
       regional_currency_exchange_master_public_key_expected: "TW6K5FXF81VYCAH0YWYX0SX98KBBSJ42VX27WAX01FTFH400QG10"
       regional_currency_exchange_master_priv_src: "{{ lookup('ansible.builtin.env', 'HOME') }}/git/admin-logs/koopa-admin-secrets/backups/goa/current/exchange-offline/master.priv"