diff --git a/README.md b/README.md
index de97960..b817051 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@ This project creates customized error pages that mimics the well-known Cloudflar
 
 ## Online Editor
 
-Here's an online editor to create customized error pages. Try it out [here](https://virt.moe/cferr/editor/).
+Here's an online editor to create customized error pages and example server apps. Try it out [here](https://virt.moe/cferr/editor/).
 
 ![Editor](https://github.com/donlon/cloudflare-error-page/blob/images/editor.png?raw=true)
 
diff --git a/editor/web/index.html b/editor/web/index.html
index 93415a1..cf6bde3 100644
--- a/editor/web/index.html
+++ b/editor/web/index.html
@@ -173,7 +173,7 @@
       max-height: 1200px !important;
       font-family: monospace;
       font-size: 0.8em !important;
-      overflow: auto;
+      overflow: hidden;
     }
 
     .save-as-dialog__buttons {
@@ -475,7 +475,7 @@
             <button type="button" id="btnOpen" class="btn btn-sm btn-primary">Preview in new tab</button>
             <!-- Button trigger modal -->
             <button type="button" class="btn btn-sm btn-primary" data-bs-toggle="modal" data-bs-target="#saveAsDialog">
-              Save as...
+              Save as & Examples ...
             </button>
           </div>
 
@@ -547,7 +547,9 @@
                 Save
               </button>
             </div>
-            <pre id="saveAsDialogCode" class="border px-2 py-1 save-as-dialog__code"></pre>
+            <div class="border rounded save-as-dialog__code">
+              <pre id="saveAsDialogCode" class="px-2 py-1 h-100"></pre>
+            </div>
           </div>
         </div>
       </div>
diff --git a/editor/web/src/codegen/index.ts b/editor/web/src/codegen/index.ts
index b871936..91ca7a8 100644
--- a/editor/web/src/codegen/index.ts
+++ b/editor/web/src/codegen/index.ts
@@ -1,4 +1,5 @@
 import ejs from 'ejs';
+import { ErrorPageParams } from 'cloudflare-error-page';
 
 import jsTemplate from './js.ejs?raw';
 import jsonTemplate from './json.ejs?raw';
@@ -7,23 +8,97 @@ import pythonTemplate from './python.ejs?raw';
 interface CodeGen {
   name: string;
   language: string;
-  generate(params: any): string;
+  generate(params: ErrorPageParams): string;
 }
 
 class EjsCodeGen implements CodeGen {
   name: string;
   language: string;
   private template: ejs.TemplateFunction;
-  constructor(name: string, language: string, templateContent: any) {
+  constructor(name: string, language: string, templateContent: string) {
     this.name = name;
     this.language = language;
     this.template = ejs.compile(templateContent);
   }
-  generate(params: any): string {
-    return this.template({ params });
+  protected prepareTemplateArgs(params: ErrorPageParams): Record<string, any> {
+    return {};
+  }
+  generate(params: ErrorPageParams): string {
+    const moreArgs = this.prepareTemplateArgs(params);
+    return this.template({ params, ...moreArgs });
   }
 }
 
-export const jsCodeGen = new EjsCodeGen('NodeJS Example', 'javascript', jsTemplate);
+function getErrorCode(error_code?: string | number) {
+  const errorCode = error_code || '';
+  return /\d{3}/.test(errorCode + '') ? errorCode : 500;
+}
+
+class JSCodeGen extends EjsCodeGen {
+  constructor(templateContent: string) {
+    super('JavaScript Example', 'javascript', templateContent);
+  }
+  private formatJSArgs(params: ErrorPageParams): string {
+    params = { ...params };
+    const rayIdKey = Math.random() + '';
+    const clientIpKey = Math.random() + '';
+    params.ray_id = rayIdKey;
+    params.client_ip = clientIpKey;
+    const paramsArg = JSON.stringify(params, null, 2)
+      .replace(`"${rayIdKey}"`, "(req.get('Cf-Ray') ?? '').substring(0, 16)")
+      .replace(`"${clientIpKey}"`, "req.get('X-Forwarded-For') || req.socket.remoteAddress");
+    return paramsArg;
+  }
+  protected prepareTemplateArgs(params: ErrorPageParams): Record<string, any> {
+    return {
+      errorCode: getErrorCode(params.error_code),
+      // TODO: format to JS-style object (key w/o parens)
+      indentedParams: this.formatJSArgs(params).replaceAll('\n', '\n  '),
+    };
+  }
+}
+
+class PythonCodeGen extends EjsCodeGen {
+  constructor(templateContent: string) {
+    super('Python Example', 'python', templateContent);
+  }
+  private formatPythonArgs(params: ErrorPageParams): string {
+    // Covert the parameters to Python format object
+    params = { ...params };
+    const randomKey = Math.random() + '';
+    const rayIdKey = Math.random() + '';
+    const clientIpKey = Math.random() + '';
+    params.ray_id = rayIdKey;
+    params.client_ip = clientIpKey;
+    const paramsArg = JSON.stringify(
+      params,
+      (key, value) => {
+        if (typeof value === 'boolean') {
+          return randomKey + value.toString();
+        } else if (value === null) {
+          return randomKey + 'null';
+        } else {
+          return value;
+        }
+      },
+      4
+    )
+      .replace(`"${randomKey}true"`, 'True')
+      .replace(`"${randomKey}false"`, 'False')
+      .replace(`"${randomKey}null"`, 'None')
+      .replace(`"${rayIdKey}"`, 'request.headers.get("Cf-Ray", "")[:16]')
+      .replace(`"${clientIpKey}"`, 'request.headers.get("X-Forwarded-For") or request.remote_addr');
+    return paramsArg;
+  }
+  protected prepareTemplateArgs(params: ErrorPageParams): Record<string, any> {
+    return {
+      errorCode: getErrorCode(params.error_code),
+      // TODO: format to JS-style object (key w/o parens)
+      indentedParams: this.formatPythonArgs(params).replaceAll('\n', '\n    '),
+    };
+  }
+}
+
+export const jsCodeGen = new JSCodeGen(jsTemplate);
 export const jsonCodeGen = new EjsCodeGen('JSON', 'json', jsonTemplate);
-export const pythonCodeGen = new EjsCodeGen('Python Example', 'python', pythonTemplate);
+export const pythonCodeGen = new PythonCodeGen(pythonTemplate);
diff --git a/editor/web/src/codegen/js.ejs b/editor/web/src/codegen/js.ejs
index 9f4a506..31aa8a6 100644
--- a/editor/web/src/codegen/js.ejs
+++ b/editor/web/src/codegen/js.ejs
@@ -1,3 +1,11 @@
+#!/usr/bin/env node
+/*
+ * JavaScript Example: Render and serve the Cloudflare error page using Express server
+ *
+ * Prerequisits:
+ *   npm install cloudflare-error-page
+ */
+
 import express from 'express';
 import { render as render_cf_error_page } from 'cloudflare-error-page';
 
@@ -5,10 +13,8 @@ const app = express();
 const port = 3000;
 
 // Define a route for GET requests to the root URL
-<%# TODO: format to JS-style object (key w/o parens) _%>
-<% const errorCode = params.error_code || 500 _%>
 app.get('/', (req, res) => {
-  res.status(<%= /\d{3}/.test(errorCode + '') ? errorCode : 500 %>).send(render_cf_error_page(<%-JSON.stringify(params, null, 2).replaceAll('\n', '\n  ')%>));
+  res.status(<%= errorCode %>).send(render_cf_error_page(<%- indentedParams %>));
 });
 
 // Start the server and listen on the specified port
diff --git a/editor/web/src/codegen/json.ejs b/editor/web/src/codegen/json.ejs
index ff9d4ad..f506349 100644
--- a/editor/web/src/codegen/json.ejs
+++ b/editor/web/src/codegen/json.ejs
@@ -1 +1 @@
-<%-JSON.stringify(params, null, 4)%>
+<%- JSON.stringify(params, null, 4) %>
diff --git a/editor/web/src/codegen/python.ejs b/editor/web/src/codegen/python.ejs
index 1266634..772b1a6 100644
--- a/editor/web/src/codegen/python.ejs
+++ b/editor/web/src/codegen/python.ejs
@@ -1,31 +1,21 @@
-<%
-// Covert the parameters to Python format object
-const randomKey = Math.random() + ''
-const paramsArg = JSON.stringify(params, (key, value) => {
-    if (typeof value === 'boolean') {
-        return randomKey + value.toString()
-    } else if (value === null) {
-        return randomKey + 'null'
-    } else {
-        return value
-    }
-}, 4)
-    .replace(`"${randomKey}true"`, 'True')
-    .replace(`"${randomKey}false"`, 'False')
-    .replace(`"${randomKey}null"`, 'None')
+#!/usr/bin/env python3
+#
+# Python Example: Render and serve the Cloudflare error page using Flask server
+#
+# Prerequisits:
+#   pip install cloudflare-error-page
+#
 
-const errorCode = params.error_code || 500
-_%>
-from flask import Flask
+from flask import Flask, request
 from cloudflare_error_page import render as render_cf_error_page
 
 app = Flask(__name__)
 
 # Define a route for GET requests to the root URL
-@app.route('/')
+@app.route("/")
 def index():
     # Render the error page
-    return render_cf_error_page(<%- paramsArg.replaceAll('\n', '\n    ') %>), <%= /\d{3}/.test(errorCode + '') ? errorCode : 500 %>
+    return render_cf_error_page(<%- indentedParams %>), <%= errorCode %>
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     app.run(debug=True, port=5000)
diff --git a/editor/web/src/index.js b/editor/web/src/index.js
index 6dff9d4..70830db 100644
--- a/editor/web/src/index.js
+++ b/editor/web/src/index.js
@@ -431,6 +431,7 @@ function updateSaveAsDialog(e) {
   }
   const params = { ...lastCfg };
   delete params.time;
+  delete params.ray_id;
   let language;
   if (codegen) {
     saveAsContent = codegen.generate(params);
@@ -445,6 +446,7 @@ function updateSaveAsDialog(e) {
   const html = Prism.highlight(saveAsContent, Prism.languages[language], language);
 
   $('saveAsDialogCode').innerHTML = html;
+  $('saveAsDialogCode').scrollTop = 0;
 
   document.querySelectorAll('#saveAsDialogTypes button').forEach((element) => {
     const isCurrent = element.dataset.type == saveAsType;
diff --git a/javascript/src/index.ts b/javascript/src/index.ts
index 8c2d99c..f827ce8 100644
--- a/javascript/src/index.ts
+++ b/javascript/src/index.ts
@@ -52,7 +52,9 @@ export interface ErrorPageParams {
 }
 
 // Load EJS template
-export const baseTemplate: ejs.TemplateFunction = ejs.compile(templateString);
+export const baseTemplate: ejs.TemplateFunction = ejs.compile(templateString, {
+  rmWhitespace: true
+});
 
 /**
  * Generate random hex string for ray-id