diff --git a/contrib/html/openapi.yaml b/contrib/html/openapi.yaml
index dfe2987b..1b63604e 100644
--- a/contrib/html/openapi.yaml
+++ b/contrib/html/openapi.yaml
@@ -2,7 +2,7 @@ openapi: 3.1.0
 info:
   title: ebusd-http
   description: The API that ebusd provides on HTTP port.
-  version: "21.3"
+  version: "22.3"
 servers:
   - url: http://127.0.0.1:8080/
 paths:
@@ -530,6 +530,9 @@ components:
         isignored:
           type: boolean
           description: whether the result is ignored.
+        isreverse:
+          type: boolean
+          description: whether the symbols are in reverse order (most significant byte first).
         length:
           type: number
           minimum: -1
diff --git a/src/lib/ebus/datatype.cpp b/src/lib/ebus/datatype.cpp
index 4d4615ab..1d299da2 100755
--- a/src/lib/ebus/datatype.cpp
+++ b/src/lib/ebus/datatype.cpp
@@ -50,6 +50,7 @@ bool DataType::dump(OutputFormat outputFormat, size_t length, bool appendDivisor
     if (outputFormat & OF_ALL_ATTRS) {
       *output << ", \"isadjustable\": " << (isAdjustableLength() ? "true" : "false");
       *output << ", \"isignored\": " << (isIgnored() ? "true" : "false");
+      *output << ", \"isreverse\": " << (hasFlag(REV) ? "true" : "false");
     }
     *output << ", \"length\": ";
     if (isAdjustableLength() && length == REMAIN_LEN) {