diff --git a/src/net/nl_api.c b/src/net/nl_api.c
index a6ef00c..d85608b 100644
--- a/src/net/nl_api.c
+++ b/src/net/nl_api.c
@@ -265,6 +265,13 @@ static void handle_info(const nl_api_ctx_t *ctx, nl_api_response_t *resp)
         cJSON_AddStringToObject(o, "last_ota_error", in.last_ota_error);
     else
         cJSON_AddNullToObject(o, "last_ota_error");
+    {
+        nl_settings_t s;
+        cJSON *sa = cJSON_AddObjectToObject(o, "sacn");
+        ctx->get_settings(&s);
+        cJSON_AddBoolToObject(sa, "active", in.sacn_active);
+        cJSON_AddNumberToObject(sa, "universe", s.sacn_universe);
+    }
     reply_json(resp, 200, o);
 }
 
@@ -286,6 +293,16 @@ static void handle_get_settings(const nl_api_ctx_t *ctx, nl_api_response_t *resp
      * kommen, ohne die Bedeutung von "ssid" zu aendern. */
     cJSON_AddStringToObject(w, "source", s.wifi_ssid[0] ? "stored" : "compiled");
     cJSON_AddBoolToObject(o, "auth_all", s.auth_all != 0);
+    {
+        cJSON *sa = cJSON_AddObjectToObject(o, "sacn");
+        cJSON_AddBoolToObject(sa, "enabled", s.sacn_enabled != 0);
+        cJSON_AddNumberToObject(sa, "universe", s.sacn_universe);
+        cJSON_AddNumberToObject(sa, "start_slot", s.sacn_start_slot);
+        cJSON_AddStringToObject(sa, "on_timeout", s.sacn_hold ? "hold" : "release");
+        /* Informativ und bewusst aus dem Board, nicht aus dem Datensatz: so steht beim
+         * Adressieren direkt da, wieviel Platz diese Lampe im Universe belegt. */
+        cJSON_AddNumberToObject(sa, "slots", nl_board_dmx_slots(ctx->board));
+    }
     reply_json(resp, 200, o);
 }
 
@@ -333,6 +350,34 @@ static void handle_put_settings(const nl_api_ctx_t *ctx, const nl_http_request_t
             err = "invalid all";
         else
             s.auth_all = cJSON_IsTrue(all) ? 1 : 0;
+    } else if (strcmp(type, "sacn") == 0) {
+        const cJSON *en = cJSON_GetObjectItemCaseSensitive(j, "enabled");
+        const cJSON *un = cJSON_GetObjectItemCaseSensitive(j, "universe");
+        const cJSON *st = cJSON_GetObjectItemCaseSensitive(j, "start_slot");
+        const char  *ot = NULL;
+        int          otp;
+        uint8_t      slots = nl_board_dmx_slots(ctx->board);
+
+        if (en && !cJSON_IsBool(en)) {
+            err = "invalid enabled";
+        } else if (un && (!cJSON_IsNumber(un) || un->valuedouble < 1 || un->valuedouble > 63999)) {
+            err = "invalid universe";
+        } else if (st && (!cJSON_IsNumber(st) || st->valuedouble < 1 ||
+                          st->valuedouble + slots - 1 > 512)) {
+            err = "invalid start_slot";
+        } else if ((otp = get_string(j, "on_timeout", 1, 16, &ot)) < 0 ||
+                   (otp == 1 && strcmp(ot, "release") != 0 && strcmp(ot, "hold") != 0)) {
+            err = "invalid on_timeout";
+        } else {
+            if (en)
+                s.sacn_enabled = cJSON_IsTrue(en) ? 1 : 0;
+            if (un)
+                s.sacn_universe = (uint16_t)un->valuedouble;
+            if (st)
+                s.sacn_start_slot = (uint16_t)st->valuedouble;
+            if (otp == 1)
+                s.sacn_hold = strcmp(ot, "hold") == 0 ? 1 : 0;
+        }
     } else {
         err = "invalid type";
     }
diff --git a/src/net/nl_api.h b/src/net/nl_api.h
index 83980ee..21e977f 100644
--- a/src/net/nl_api.h
+++ b/src/net/nl_api.h
@@ -24,6 +24,7 @@ typedef struct {
     uint32_t    uptime_s;
     uint32_t    free_heap;
     const char *last_ota_error; /* NULL until OTA exists */
+    bool        sacn_active; /* true, solange die Lampe ferngesteuert wird */
 } nl_sys_info_t;
 
 /* Everything the API needs from the application; implemented by src/sys/nl_app_api.c. */
diff --git a/test/test_api.c b/test/test_api.c
index ca25feb..553c5be 100644
--- a/test/test_api.c
+++ b/test/test_api.c
@@ -346,6 +346,113 @@ static void test_settings_name_token_auth(void)
     TEST_ASSERT_EQUAL_INT(500, resp.status);
 }
 
+/* --- system/settings: sacn --- */
+static const cJSON *sacn_field(const char *name)
+{
+    const cJSON *s = cJSON_GetObjectItemCaseSensitive(doc, "sacn");
+    return cJSON_GetObjectItemCaseSensitive(s, name);
+}
+
+static void test_settings_exposes_sacn_block(void)
+{
+    call(NL_HTTP_GET, "/api/v1/system/settings", TOKEN, NULL);
+    TEST_ASSERT_EQUAL_INT(200, resp.status);
+    TEST_ASSERT_TRUE(cJSON_IsTrue(sacn_field("enabled")));
+    TEST_ASSERT_EQUAL_INT(1, (int)cJSON_GetNumberValue(sacn_field("universe")));
+    TEST_ASSERT_EQUAL_INT(1, (int)cJSON_GetNumberValue(sacn_field("start_slot")));
+    TEST_ASSERT_EQUAL_STRING("release", cJSON_GetStringValue(sacn_field("on_timeout")));
+    TEST_ASSERT_EQUAL_INT(6, (int)cJSON_GetNumberValue(sacn_field("slots")));
+}
+
+static void test_settings_sacn_block_reflects_stored_values(void)
+{
+    fake_settings.sacn_enabled = 0;
+    fake_settings.sacn_universe = 12;
+    fake_settings.sacn_start_slot = 7;
+    fake_settings.sacn_hold = 1;
+    call(NL_HTTP_GET, "/api/v1/system/settings", TOKEN, NULL);
+    TEST_ASSERT_FALSE(cJSON_IsTrue(sacn_field("enabled")));
+    TEST_ASSERT_EQUAL_INT(12, (int)cJSON_GetNumberValue(sacn_field("universe")));
+    TEST_ASSERT_EQUAL_INT(7, (int)cJSON_GetNumberValue(sacn_field("start_slot")));
+    TEST_ASSERT_EQUAL_STRING("hold", cJSON_GetStringValue(sacn_field("on_timeout")));
+}
+
+static void test_put_sacn_all_fields(void)
+{
+    call(NL_HTTP_PUT, "/api/v1/system/settings", TOKEN,
+         "{\"type\":\"sacn\",\"enabled\":false,\"universe\":300,"
+         "\"start_slot\":100,\"on_timeout\":\"hold\"}");
+    TEST_ASSERT_EQUAL_INT(200, resp.status);
+    TEST_ASSERT_EQUAL_INT(1, fake_save_calls);
+    TEST_ASSERT_EQUAL_UINT8(0, fake_settings.sacn_enabled);
+    TEST_ASSERT_EQUAL_UINT16(300, fake_settings.sacn_universe);
+    TEST_ASSERT_EQUAL_UINT16(100, fake_settings.sacn_start_slot);
+    TEST_ASSERT_EQUAL_UINT8(1, fake_settings.sacn_hold);
+}
+
+static void test_put_sacn_single_field_leaves_rest(void)
+{
+    fake_settings.sacn_universe = 9;
+    fake_settings.sacn_hold = 1;
+    call(NL_HTTP_PUT, "/api/v1/system/settings", TOKEN,
+         "{\"type\":\"sacn\",\"start_slot\":50}");
+    TEST_ASSERT_EQUAL_INT(200, resp.status);
+    TEST_ASSERT_EQUAL_UINT16(50, fake_settings.sacn_start_slot);
+    TEST_ASSERT_EQUAL_UINT16(9, fake_settings.sacn_universe);
+    TEST_ASSERT_EQUAL_UINT8(1, fake_settings.sacn_hold);
+}
+
+static void test_put_sacn_rejects_bad_values(void)
+{
+    call(NL_HTTP_PUT, "/api/v1/system/settings", TOKEN, "{\"type\":\"sacn\",\"enabled\":\"ja\"}");
+    TEST_ASSERT_EQUAL_INT(400, resp.status);
+    TEST_ASSERT_EQUAL_STRING("invalid enabled", error_text());
+
+    call(NL_HTTP_PUT, "/api/v1/system/settings", TOKEN, "{\"type\":\"sacn\",\"universe\":0}");
+    TEST_ASSERT_EQUAL_INT(400, resp.status);
+    TEST_ASSERT_EQUAL_STRING("invalid universe", error_text());
+
+    call(NL_HTTP_PUT, "/api/v1/system/settings", TOKEN, "{\"type\":\"sacn\",\"universe\":64000}");
+    TEST_ASSERT_EQUAL_STRING("invalid universe", error_text());
+
+    call(NL_HTTP_PUT, "/api/v1/system/settings", TOKEN, "{\"type\":\"sacn\",\"start_slot\":0}");
+    TEST_ASSERT_EQUAL_STRING("invalid start_slot", error_text());
+
+    call(NL_HTTP_PUT, "/api/v1/system/settings", TOKEN, "{\"type\":\"sacn\",\"on_timeout\":\"halten\"}");
+    TEST_ASSERT_EQUAL_STRING("invalid on_timeout", error_text());
+
+    TEST_ASSERT_EQUAL_INT(0, fake_save_calls); /* nichts davon darf gespeichert werden */
+}
+
+/* Ein Board mit RGB braucht 6 Slots: ab 508 passt der Satz nicht mehr ins Universe. */
+static void test_put_sacn_start_slot_must_leave_room_for_all_slots(void)
+{
+    call(NL_HTTP_PUT, "/api/v1/system/settings", TOKEN, "{\"type\":\"sacn\",\"start_slot\":507}");
+    TEST_ASSERT_EQUAL_INT(200, resp.status);
+    call(NL_HTTP_PUT, "/api/v1/system/settings", TOKEN, "{\"type\":\"sacn\",\"start_slot\":508}");
+    TEST_ASSERT_EQUAL_INT(400, resp.status);
+    TEST_ASSERT_EQUAL_STRING("invalid start_slot", error_text());
+}
+
+static void test_put_sacn_start_slot_limit_follows_the_board(void)
+{
+    fake_api_reset("g95_cw"); /* drei Slots: 510 passt noch */
+    call(NL_HTTP_PUT, "/api/v1/system/settings", TOKEN, "{\"type\":\"sacn\",\"start_slot\":510}");
+    TEST_ASSERT_EQUAL_INT(200, resp.status);
+    call(NL_HTTP_PUT, "/api/v1/system/settings", TOKEN, "{\"type\":\"sacn\",\"start_slot\":511}");
+    TEST_ASSERT_EQUAL_INT(400, resp.status);
+}
+
+static void test_info_exposes_sacn_state(void)
+{
+    fake_info.sacn_active = true;
+    fake_settings.sacn_universe = 5;
+    call(NL_HTTP_GET, "/api/v1/system/info", NULL, NULL);
+    TEST_ASSERT_EQUAL_INT(200, resp.status);
+    TEST_ASSERT_TRUE(cJSON_IsTrue(sacn_field("active")));
+    TEST_ASSERT_EQUAL_INT(5, (int)cJSON_GetNumberValue(sacn_field("universe")));
+}
+
 /* --- system/command --- */
 static void test_commands(void)
 {
@@ -406,6 +513,14 @@ int main(void)
     RUN_TEST(test_settings_wifi_source_reflects_compiled_fallback);
     RUN_TEST(test_settings_wifi);
     RUN_TEST(test_settings_name_token_auth);
+    RUN_TEST(test_settings_exposes_sacn_block);
+    RUN_TEST(test_settings_sacn_block_reflects_stored_values);
+    RUN_TEST(test_put_sacn_all_fields);
+    RUN_TEST(test_put_sacn_single_field_leaves_rest);
+    RUN_TEST(test_put_sacn_rejects_bad_values);
+    RUN_TEST(test_put_sacn_start_slot_must_leave_room_for_all_slots);
+    RUN_TEST(test_put_sacn_start_slot_limit_follows_the_board);
+    RUN_TEST(test_info_exposes_sacn_state);
     RUN_TEST(test_commands);
     return UNITY_END();
 }