diff --git a/.gitea/workflows/validate.yaml b/.gitea/workflows/validate.yaml
new file mode 100644
index 0000000..73cc524
--- /dev/null
+++ b/.gitea/workflows/validate.yaml
@@ -0,0 +1,21 @@
+name: Validate and Test
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  validate-patches:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+      - name: Install dependencies
+        run: |
+          pip install conftest
+      - name: Validate all .pd patches
+        run: |
+          python3 pd-validator/validate.py pd/*.pd
diff --git a/justfile b/justfile
index d6fd668..23019f7 100644
--- a/justfile
+++ b/justfile
@@ -341,6 +341,10 @@ kconfig:
 validate:
     python3 pd-validator/validate.py pd/*.pd
 
+# CI: run full validation suite (same as validate but used by Gitea Actions)
+ci:
+    python3 pd-validator/validate.py pd/*.pd
+
 # Install udev rules for hotplug role changes
 install-udev-rules:
     @ssh {{SSH_OPTS}} "{{BOARD_USER}}@{{BOARD_HOST}}" "\
diff --git a/pd/mpk-mini-sim.pd b/pd/mpk-mini-sim.pd
index d05950a..41afddb 100644
--- a/pd/mpk-mini-sim.pd
+++ b/pd/mpk-mini-sim.pd
@@ -1,4 +1,5 @@
 #N canvas 0 0 950 490 10;
+# DO NOT EDIT — generated by scripts/gen_mpk_sim.py;
 #X obj 10 10 loadbang ;
 #X msg 10 30 ;;
 #X msg 10 50 connect 192.168.9.167 8081;;
diff --git a/pd/synth.pd b/pd/synth.pd
index 01843f4..98f78a8 100644
--- a/pd/synth.pd
+++ b/pd/synth.pd
@@ -1,33 +1,65 @@
-#N canvas 0 0 500 600 10;
-#X obj 40 20 midi-in;
-#X obj 40 80 stripnote;
-#X obj 40 140 mtof;
-#X obj 40 180 osc~;
-#X obj 160 180 osc~;
-#X obj 40 220 *~ 1;
-#X obj 160 220 *~ 1;
-#X obj 100 260 +~;
-#X obj 100 300 lop~ 10000;
-#X obj 40 340 env~ 2 10 1 40;
-#X obj 100 380 *~;
-#X obj 100 440 audio-out;
-#X text 200 180 osc~ 1 (main);
-#X text 320 180 osc~ 2 (+7ct);
-#X text 155 220 mix;
-#X text 155 300 lop~;
-#X text 155 340 envelope;
-#X text 155 380 amp;
+#N canvas 0 0 900 550 10;
+# DO NOT EDIT — generated by scripts/gen_synth_pd.py;
+#X obj 20 20 notein;
+#X obj 80 50 pack 0 0;
+#X obj 80 80 unpack 0 0;
+#X obj 20 110 s midi-pitch;
+#X obj 80 110 s midi-vel;
+#X obj 400 20 netreceive -u 8081;
+#X obj 400 60 route midi;
+#X obj 400 100 route 144 128;
+#X obj 400 140 unpack 0 0;
+#X obj 480 140 unpack 0 0;
+#X obj 400 180 s midi-pitch;
+#X obj 480 180 s midi-vel;
+#X obj 20 160 r midi-vel;
+#X obj 20 190 r midi-pitch;
+#X obj 20 220 stripnote;
+#X obj 20 260 mtof;
+#X obj 20 290 env~ 50 200 0.7 400;
+#X obj 140 260 osc~;
+#X obj 140 290 *~ 0.3;
+#X obj 220 260 osc~;
+#X obj 220 290 *~ 0.3;
+#X obj 180 330 +~;
+#X obj 180 360 *~ 0.5;
+#X obj 180 400 lop~;
+#X obj 180 460 *~;
+#X obj 320 460 *~;
+#X obj 250 530 dac~;
+#X obj 350 330 hsl 128 15 100 18000 10000 0 0 0 empty Cutoff -2 -8 0 10 -262144 -1 -1 7200 1;
+#X obj 350 430 hsl 128 15 0 100 40 0 0 0 empty Volume -2 -8 0 10 -262144 -1 -1 7200 1;
+#X obj 350 460 / 100;
 #X connect 0 0 1 0;
 #X connect 0 1 1 1;
 #X connect 1 0 2 0;
-#X connect 1 1 9 1;
 #X connect 2 0 3 0;
-#X connect 2 0 4 0;
-#X connect 3 0 5 0;
-#X connect 4 0 6 0;
-#X connect 5 0 7 0;
-#X connect 6 0 7 1;
+#X connect 2 1 4 0;
+#X connect 5 0 6 0;
+#X connect 6 0 7 0;
 #X connect 7 0 8 0;
+#X connect 7 1 9 0;
 #X connect 8 0 10 0;
-#X connect 9 0 10 1;
-#X connect 10 0 11 0;
+#X connect 8 1 11 0;
+#X connect 9 0 10 0;
+#X connect 9 1 11 0;
+#X connect 12 0 14 1;
+#X connect 13 0 14 0;
+#X connect 14 0 15 0;
+#X connect 15 0 17 0;
+#X connect 15 0 19 0;
+#X connect 17 0 18 0;
+#X connect 19 0 20 0;
+#X connect 18 0 21 0;
+#X connect 20 0 21 1;
+#X connect 21 0 22 0;
+#X connect 22 0 23 0;
+#X connect 23 0 24 0;
+#X connect 14 0 16 0;
+#X connect 16 0 24 1;
+#X connect 24 0 25 0;
+#X connect 27 0 23 1;
+#X connect 28 0 29 0;
+#X connect 29 0 25 1;
+#X connect 25 0 26 0;
+#X connect 25 0 26 1;
diff --git a/scripts/gen_mpk_sim.py b/scripts/gen_mpk_sim.py
index a4b63f0..04a1c2e 100644
--- a/scripts/gen_mpk_sim.py
+++ b/scripts/gen_mpk_sim.py
@@ -93,7 +93,10 @@ def gen():
         connect(c, msg, 0, ns, 0)
 
     # ── Write (Pd format: #X obj for objects, #X msg/text/floatatom/symbol for others) ──
-    lines = ["#N canvas 0 0 950 490 10;"]
+    lines = [
+        "#N canvas 0 0 950 490 10;",
+        "# DO NOT EDIT — generated by scripts/gen_mpk_sim.py;",
+    ]
     obj_types = {"bng","t","del","netsend","loadbang","hsl","comment"}
     for x, y, *args in o:
         etype = args[0]
diff --git a/scripts/gen_synth_pd.py b/scripts/gen_synth_pd.py
index bb71397..d3170af 100644
--- a/scripts/gen_synth_pd.py
+++ b/scripts/gen_synth_pd.py
@@ -95,7 +95,10 @@ def gen():
     connect(c, panscale, 0, dac, 1)
 
     # ── Write ──
-    lines = ["#N canvas 0 0 900 550 10;"]
+    lines = [
+        "#N canvas 0 0 900 550 10;",
+        "# DO NOT EDIT — generated by scripts/gen_synth_pd.py;",
+    ]
     for x, y, t, *args in o:
         joined = " ".join(str(a) for a in args)
         lines.append(f"#X obj {x} {y} {joined};")
diff --git a/scripts/start-synth.sh b/scripts/start-synth.sh
index bb15ccf..694ea10 100755
--- a/scripts/start-synth.sh
+++ b/scripts/start-synth.sh
@@ -30,6 +30,14 @@ if ! command -v pd &>/dev/null; then
     die "Pure Data not found. Install: apt install puredata"
 fi
 
+MIN_PD_VERSION="0.54.0"
+PD_VERSION=$(pd --version 2>&1 | grep -oP '[\d]+\.[\d]+-?[\d]*' | head -1 || echo "0.0.0")
+if printf '%s\n' "$MIN_PD_VERSION" "$PD_VERSION" | sort -V | head -1 | grep -q "^$MIN_PD_VERSION$"; then
+    info "Pd version $PD_VERSION (>= $MIN_PD_VERSION)"
+else
+    die "Pd version $PD_VERSION is too old. Need >= $MIN_PD_VERSION"
+fi
+
 if [ ! -f "$PATCH" ]; then
     die "Patch not found: $PATCH"
 fi
diff --git a/system/pd-synth-auto.service b/system/pd-synth-auto.service
index 0ddc962..0703d23 100644
--- a/system/pd-synth-auto.service
+++ b/system/pd-synth-auto.service
@@ -1,5 +1,6 @@
 [Unit]
 Description=Pure Data Synth (auto-detect: gadget or host)
+ConditionPathExists=/home/arduino/uno-q-audio-synth/pd/synth.pd
 Documentation=https://github.com/arduino/uno-q-audio-synth
 After=usb-role-detect.service
 Wants=usb-role-detect.service
diff --git a/system/pd-synth-i2s.service b/system/pd-synth-i2s.service
index 36d143a..2e558ee 100644
--- a/system/pd-synth-i2s.service
+++ b/system/pd-synth-i2s.service
@@ -1,5 +1,6 @@
 [Unit]
 Description=Pure Data I2S DAC Synth (standalone)
+ConditionPathExists=/home/arduino/uno-q-audio-synth/pd/synth.pd
 After=network.target sound.target
 Wants=usb-gadget-audio.service
 
diff --git a/system/pd-synth.service b/system/pd-synth.service
index 9f04504..6559d39 100644
--- a/system/pd-synth.service
+++ b/system/pd-synth.service
@@ -1,5 +1,6 @@
 [Unit]
 Description=Pure Data USB Audio Synth (Gadget Mode)
+ConditionPathExists=/home/arduino/uno-q-audio-synth/pd/synth.pd
 After=usb-gadget-audio.service midi-bridge.service
 Wants=usb-gadget-audio.service midi-bridge.service