diff --git a/README.md b/README.md
index f0cf59b..c20d0bf 100644
--- a/README.md
+++ b/README.md
@@ -11,11 +11,40 @@ Use [@apidevtools/json-schema-ref-parser](https://github.com/APIDevTools/json-sc
 
 Use [openapi-snippet](https://github.com/ErikWittern/openapi-snippet) to generate code samples automatically.
 
-### Convert string to int for int32 type in `.proto`
-
-ToDo
-
-### Import markown files
+### Convert the example and default values of integer type to int
+
+A `int32` type `port` defined in the `.proto` file is:
+
+```proto
+int32 port = 1 [(grpc.gateway.protoc_gen_openapiv2.options.openapiv2_field) = {
+    format: "int32",
+    default: "8080",
+    example: "8080"
+```
+
+The default JSON generated by `bufbuild/buf` is:
+
+```json
+"port": {
+  "type": "integer",
+  "format": "int32",
+  "example": 8080,
+  "default": "8080"
+}
+```
+
+`replaceint.js` replaces all integer values and the processed JSON file is:
+
+```json
+"port": {
+  "type": "integer",
+  "format": "int32",
+  "example": 8080,
+  "default": 8080
+}
+```
+
+### Import markdown files
 
 Embed external Markdown file contents to the `info.description` auto-generated JSON file. See [Redoc documentation](https://redocly.com/docs/api-reference-docs/guides/embedded-markdown/) for more information.
 
diff --git a/src/main.js b/src/main.js
index f80c238..f392d43 100644
--- a/src/main.js
+++ b/src/main.js
@@ -5,6 +5,7 @@ const importMd = require("./importmd.js");
 const addLogo = require("./addlogo.js");
 const genSampleCode = require("./gencode.js");
 const devTier = require("./devTier.js");
+const replaceInteger = require("./replaceint.js");
 
 const program = new Command();
 program
@@ -37,4 +38,9 @@ program.command("devtier")
     .description("Add sample for creating a dev tier cluster")
     .argument("<in-filename", "Target JSON file")
     .action(devTier)
+program.command("replaceint")
+    .description("Replace the example and default value of integer type to number type")
+    .argument("<in-filename>", "Input JSON file")
+    .argument("[out-filename]", "Output JSON file. If not specified, use in-filename.")
+    .action(replaceInteger);
 program.parse();
diff --git a/src/replaceint.js b/src/replaceint.js
new file mode 100644
index 0000000..7720eaa
--- /dev/null
+++ b/src/replaceint.js
@@ -0,0 +1,28 @@
+const fs = require("fs");
+
+function replaceIntegerInternal(obj) {
+    for (let item in obj) {
+        if (obj[item] instanceof Object) {
+            replaceIntegerInternal(obj[item]);
+        }
+        else if (item == "type" && obj[item] === "integer") {
+            if (obj["example"] != undefined && typeof obj["example"] != "number") {
+                obj["example"] = parseInt(obj["example"]);
+            }
+            if (obj["default"] != undefined && typeof obj["default"] != "number") {
+                obj["default"] = parseInt(obj["default"]);
+            }
+        }
+    }
+    return obj;
+}
+
+async function replaceInteger(readf, writef) {
+    writef = writef || readf;
+    const data = JSON.parse(fs.readFileSync(readf, 'utf8'));
+    const schema = replaceIntegerInternal(data);
+    fs.writeFileSync(writef, JSON.stringify(schema, null, 2));
+    console.log(`Replace wrong string with int in ${writef}`);
+}
+
+module.exports = replaceInteger;