diff --git a/package.json b/package.json
index 076b6226..1df4d91d 100644
--- a/package.json
+++ b/package.json
@@ -53,7 +53,9 @@
     "traces:markdown": "bun run scripts/extract-traces.ts --format markdown > docs/traceability.md",
     "traces:coverage": "bun run scripts/extract-traces.ts --format coverage",
     "traces:validate": "bun run scripts/extract-traces.ts --format validate",
-    "release:notes": "bun run scripts/release-notes.ts"
+    "release:notes": "bun run scripts/release-notes.ts",
+    "test:player": "./scripts/test-player-conformance.sh",
+    "test:player:android": "./scripts/test-player-conformance.sh android"
   },
   "dependencies": {
     "@tauri-apps/api": "^2.11.1",
diff --git a/scripts/test-player-conformance.sh b/scripts/test-player-conformance.sh
new file mode 100755
index 00000000..75e6b01a
--- /dev/null
+++ b/scripts/test-player-conformance.sh
@@ -0,0 +1,60 @@
+#!/usr/bin/env bash
+# Run the MediaPlayer conformance suite.
+#
+# See docs/specs/media-player-controller.md. One set of behaviours, run against
+# every engine — so a wrapper is verified without building or launching the app.
+#
+#   ./scripts/test-player-conformance.sh              desktop engines (mpv, legacy)
+#   ./scripts/test-player-conformance.sh android      ExoPlayer, on a connected device
+#
+set -euo pipefail
+
+PROJECT_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+TARGET="${1:-desktop}"
+
+run_desktop() {
+    local fixture="${TMPDIR:-/tmp}/jellytau-conformance-1200s.mp4"
+    if [ ! -f "$fixture" ]; then
+        # Generated, not committed: the repo carries no media, and the duration
+        # is exact — the seek assertions depend on it.
+        echo "Generating a 20-minute fixture at $fixture"
+        ffmpeg -y -loglevel error \
+            -f lavfi -i "testsrc2=size=640x360:rate=25" \
+            -f lavfi -i "sine=frequency=440" \
+            -t 1200 -c:v libx264 -preset ultrafast -pix_fmt yuv420p -g 50 \
+            -c:a aac -shortest "$fixture"
+    fi
+
+    cd "$PROJECT_ROOT/src-tauri"
+    local status=0
+    for engine in mpv legacy; do
+        echo
+        cargo run --quiet --features conformance --bin player-conformance -- \
+            "$fixture" "$engine" || status=1
+    done
+    return $status
+}
+
+run_android() {
+    if ! adb get-state >/dev/null 2>&1; then
+        echo "No device. Connect one and enable USB debugging." >&2
+        exit 1
+    fi
+
+    "$PROJECT_ROOT/scripts/sync-android-sources.sh" >/dev/null
+    cd "$PROJECT_ROOT/src-tauri/gen/android"
+
+    # `-x rustBuild...` because raw gradle drives the Rust build through Tauri's
+    # android-studio-script, which expects a dev-server address file that only
+    # exists under `tauri android dev`. The native library already in
+    # app/src/main/jniLibs is what the test process loads.
+    ANDROID_HOME="${ANDROID_HOME:-$HOME/Android/Sdk}" \
+        ./gradlew :app:connectedUniversalDebugAndroidTest \
+        -x :app:rustBuildUniversalDebug --console=plain
+}
+
+case "$TARGET" in
+    desktop) run_desktop ;;
+    android) run_android ;;
+    *) echo "usage: $0 [desktop|android]" >&2; exit 2 ;;
+esac