diff --git a/README.md b/README.md
index d7c61f7..47d317f 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,7 @@ pnpm run plugins i ep_post_data
 ## Usage
 
 POST to `/post` to create or update a pad. Set the `X-PAD-ID` header to choose the pad name, otherwise a random ID is generated.
+Use `PATCH /post` to append content to an existing pad (or create it if it does not exist).
 
 ```bash
 # Create a pad with a random ID
@@ -18,6 +19,9 @@ curl -X POST -d @datafile.txt http://localhost:9001/post
 
 # Create or update a specific pad
 curl -X POST -d @datafile.txt -H 'X-PAD-ID: mypad' http://localhost:9001/post
+
+# Append to a specific pad (or create it if missing)
+curl -X PATCH -d @datafile.txt -H 'X-PAD-ID: mypad' http://localhost:9001/post
 ```
 
 ## Limits
diff --git a/index.js b/index.js
index 169c138..3709cdb 100644
--- a/index.js
+++ b/index.js
@@ -6,7 +6,7 @@ const randomString = require('ep_etherpad-lite/static/js/pad_utils').randomStrin
 const MAX_BODY_SIZE = 1024 * 1024; // 1 MB
 
 exports.registerRoute = (hookName, args, callback) => {
-  args.app.post('/post', (req, res) => {
+  const upsertPadFromRequest = (req, res, shouldAppend) => {
     let padId = req.headers['x-pad-id'];
     if (padId === undefined) {
       padId = randomString(8);
@@ -49,15 +49,24 @@ exports.registerRoute = (hookName, args, callback) => {
       // Pad already exists so updating an existing pad.
       if (padExists) {
         try {
-          console.debug('ep_post_data: Setting text!', padId, content);
-          await API.setText(padId, content);
-          res.send('Success updating pad');
+          if (shouldAppend) {
+            console.debug('ep_post_data: Appending text!', padId, content);
+            await API.appendText(padId, content);
+            res.send('Success appending to pad');
+          } else {
+            console.debug('ep_post_data: Setting text!', padId, content);
+            await API.setText(padId, content);
+            res.send('Success updating pad');
+          }
         } catch (e) {
           console.error('ep_post_data: Error updating pad', padId, e);
           res.send('Error updating pad');
         }
       }
     });
-  });
+  };
+
+  args.app.post('/post', (req, res) => upsertPadFromRequest(req, res, false));
+  args.app.patch('/post', (req, res) => upsertPadFromRequest(req, res, true));
   callback();
 };
diff --git a/static/tests/frontend-new/specs/smoke.spec.ts b/static/tests/frontend-new/specs/smoke.spec.ts
index 58d0d30..54db667 100644
--- a/static/tests/frontend-new/specs/smoke.spec.ts
+++ b/static/tests/frontend-new/specs/smoke.spec.ts
@@ -5,9 +5,55 @@ test.beforeEach(async ({page}) => {
   await goToNewPad(page);
 });
 
+const getPadIdFromUrl = (url: string) => {
+  const match = /\/p\/([^/?#]+)/.exec(url);
+  if (!match) throw new Error(`Failed to parse pad id from URL: ${url}`);
+  return match[1];
+};
+
+const absoluteUrl = (pageUrl: string, path: string) => new URL(path, pageUrl).toString();
+
 test.describe('ep_post_data', () => {
   test('pad loads with plugin installed', async ({page}) => {
     const padBody = await getPadBody(page);
     await expect(padBody).toBeVisible();
   });
+
+  test('PATCH /post appends text to an existing pad', async ({page}) => {
+    const pageUrl = page.url();
+    const padId = getPadIdFromUrl(pageUrl);
+    const postUrl = absoluteUrl(pageUrl, '/post');
+
+    const postResponse = await page.request.post(postUrl, {
+      headers: {'X-PAD-ID': padId},
+      data: 'first',
+    });
+    expect(postResponse.ok()).toBeTruthy();
+
+    const patchResponse = await page.request.fetch(postUrl, {
+      method: 'PATCH',
+      headers: {'X-PAD-ID': padId},
+      data: ' second',
+    });
+    expect(patchResponse.ok()).toBeTruthy();
+
+    const txtResponse = await page.request.get(absoluteUrl(pageUrl, `/p/${padId}/export/txt`));
+    expect(txtResponse.ok()).toBeTruthy();
+    expect((await txtResponse.text()).trimEnd()).toBe('first second');
+  });
+
+  test('PATCH /post creates pad when it does not exist', async ({page}) => {
+    const pageUrl = page.url();
+    const padId = `ep-post-data-${Date.now().toString(36)}-${Math.random().toString(36).slice(2, 10)}`;
+    const patchResponse = await page.request.fetch(absoluteUrl(pageUrl, '/post'), {
+      method: 'PATCH',
+      headers: {'X-PAD-ID': padId},
+      data: 'created via patch',
+    });
+    expect(patchResponse.ok()).toBeTruthy();
+
+    const txtResponse = await page.request.get(absoluteUrl(pageUrl, `/p/${padId}/export/txt`));
+    expect(txtResponse.ok()).toBeTruthy();
+    expect((await txtResponse.text()).trimEnd()).toBe('created via patch');
+  });
 });