From 55ed989a833142b870fd90f17a6d3e1b0123c4a4 Mon Sep 17 00:00:00 2001
From: Aymeric Bouzigues <aymeric.bouzigues@ringcentral.com>
Date: Thu, 9 Apr 2026 15:57:27 +0200
Subject: [PATCH 1/2] Better: Add HTML sengin Guide for RIngCX Messaging

---
 .../mobile-messaging/rich-text.md             | 75 +++++++++++++++++++
 mkdocs.yml                                    |  2 +
 specs/engage-digital_openapi3.yaml            | 15 ++++
 specs/engage-digital_postman2.json            |  8 +-
 4 files changed, 99 insertions(+), 1 deletion(-)
 create mode 100644 docs/interactions/mobile-messaging/rich-text.md

diff --git a/docs/interactions/mobile-messaging/rich-text.md b/docs/interactions/mobile-messaging/rich-text.md
new file mode 100644
index 00000000..854d12be
--- /dev/null
+++ b/docs/interactions/mobile-messaging/rich-text.md
@@ -0,0 +1,75 @@
+# Sending Rich Text Messages
+
+Agent messages sent via the [Create Content API](https://developers.ringcentral.com/engage/digital/api-reference/Contents/createContent) support an optional `body_format` parameter on **RingCX Web Messaging** and **RingCX Mobile Messaging** channels where rich text has been enabled. When set to `html`, the body is interpreted as HTML and rendered natively in the client.
+
+## Request Example
+
+```bash
+curl -X POST "https://[YOUR DOMAIN].api.digital.ringcentral.com/1.0/contents"
+```
+
+```json
+{
+  "in_reply_to_id": "<in_reply_to_id>",
+  "body": "<strong>Hello</strong> <u>world</u>",
+  "body_format": "html"
+}
+```
+
+Omitting `body_format` (or setting it to `text`) treats the body as plain text, and the end customer will see the raw HTML instead of the rendered result.
+
+!!! note
+    Rich text must be enabled on the channel by an administrator before `body_format=html` can be used. Passing `body_format=html` on a channel without this feature returns a `422` error.
+
+## Supported HTML
+
+### Tags
+
+| Tag | Purpose |
+|-----|---------|
+| `<p>`, `<br>` | Paragraphs and line breaks |
+| `<strong>`, `<em>`, `<u>` | Bold, italic, underline |
+| `<h1>` – `<h6>` | Headings |
+| `<blockquote>` | Quoted text |
+| `<ul>`, `<li>` | Unordered lists (`ol` is not supported) |
+| `<a>` | Hyperlinks |
+| `<span>` | Inline styling, such as colors. |
+| `<hr>` | Horizontal rule |
+
+Any tag not in this list is rejected with a `422` status and an explicit validation error.
+
+### Attributes
+
+| Attribute | Allowed on | Notes |
+|-----------|-----------|-------|
+| `href` | `<a>` | Link target URL |
+| `target` | `<a>` | e.g. `_blank` |
+| `style` | Any | Only `color` and `text-align` are accepted (see below) |
+
+All other attributes are stripped and produce a validation error.
+
+### CSS properties
+
+Only two CSS properties are allowed inside `style`:
+
+| Property | Accepted values |
+|----------|----------------|
+| `color` | Six-digit hex only — `#RRGGBB` |
+| `text-align` | `start`, `center`, `end` |
+
+**Example of a valid HTML:**
+
+```html
+<p style="text-align:center">
+  <span style="color:#E74C3C"><strong>Important notice</strong></span>
+</p>
+<ul>
+  <li>First item</li>
+  <li>Second item</li>
+</ul>
+<a href="https://example.com" target="_blank">Learn more</a>
+```
+
+## Validation errors
+
+When the submitted HTML violates the allow-list, the API returns `422` with `error: validation_error` and an `errors` array describing each violation. Fix the offending markup and retry — no message is created until the body passes validation. Of course, when using `text`, the HTML inside the body is escaped and rendered as-is to the end-customer.
diff --git a/mkdocs.yml b/mkdocs.yml
index ee098c94..292a5bf7 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -47,8 +47,10 @@ nav:
       - 'JavaScript API': 'interactions/web-messaging/javascript-api.md'
       - 'Attachments': 'interactions/web-messaging/attachments.md'
       - 'Surveys': 'interactions/web-messaging/surveys.md'
+      - 'Sending Rich Text Messages': 'interactions/mobile-messaging/rich-text.md'
     - 'Mobile Messaging':
       - 'Huawei Push Notifications': 'interactions/mobile-messaging/huawei-push-notifications.md'
+      - 'Sending Rich Text Messages': 'interactions/mobile-messaging/rich-text.md'
     - 'Chatbots':
       - 'Overview': interactions/chatbots/overview.md
       - 'Implementation': interactions/chatbots/implementation.md
diff --git a/specs/engage-digital_openapi3.yaml b/specs/engage-digital_openapi3.yaml
index edc76522..c54f0878 100644
--- a/specs/engage-digital_openapi3.yaml
+++ b/specs/engage-digital_openapi3.yaml
@@ -1852,6 +1852,9 @@ paths:
         synchronized or if in_reply_to content is not under an ​open
         intervention.
       operationId: createContent
+      externalDocs:
+        description: Sending Rich Text Messages in RingCX Messaging
+        url: https://developers.ringcentral.com/engage/digital/guide/interactions/mobile-messaging/rich-text/
       parameters:
         - description: >-
             The identity id of content. This parameter is not mandatory, by
@@ -2006,6 +2009,18 @@ paths:
           required: false
           schema:
             type: boolean
+        - description: >-
+            RingCX Messaging only. The format of the body. When set to "html", the body
+            is interpreted as HTML and rendered natively in the client. Rich text must be
+            enabled on the channel by an administrator. Defaults to "text".
+          in: query
+          name: 'body_format'
+          required: false
+          schema:
+            type: string
+            enum:
+              - text
+              - html
       responses:
         '200':
           content:
diff --git a/specs/engage-digital_postman2.json b/specs/engage-digital_postman2.json
index 7a295ba9..9da03f9e 100644
--- a/specs/engage-digital_postman2.json
+++ b/specs/engage-digital_postman2.json
@@ -906,6 +906,12 @@
                       "value": "\u003cboolean\u003e",
                       "description": "Engage Messaging only. Allows to enable or disable customer's text input on content's thread. To disable text input, send true. To enable text input, send false. To keep as is, omit.",
                       "disabled": true
+                    },
+                    {
+                      "key": "body_format",
+                      "value": "\u003cstring\u003e",
+                      "description": "RingCX Messaging only. The format of the body. Accepted values: \"text\" (default) or \"html\". When set to \"html\", the body is interpreted as HTML and rendered natively in the client. Rich text must be enabled on the channel by an administrator. See https://engage-digital-api-docs.rtfd.org/interactions/mobile-messaging/rich-text/ for supported tags and attributes.",
+                      "disabled": true
                     }
                   ]
                 },
@@ -8173,4 +8179,4 @@
       ]
     }
   ]
-}
\ No newline at end of file
+}

From b72038c9bfc8fa826ccedf0824cf5597231495ca Mon Sep 17 00:00:00 2001
From: Aymeric Bouzigues <aymeric.bouzigues@ringcentral.com>
Date: Tue, 14 Apr 2026 14:32:43 +0200
Subject: [PATCH 2/2] Update documentation ; Removed allowed_on

---
 docs/interactions/mobile-messaging/rich-text.md | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/docs/interactions/mobile-messaging/rich-text.md b/docs/interactions/mobile-messaging/rich-text.md
index 854d12be..5511edd2 100644
--- a/docs/interactions/mobile-messaging/rich-text.md
+++ b/docs/interactions/mobile-messaging/rich-text.md
@@ -40,13 +40,13 @@ Any tag not in this list is rejected with a `422` status and an explicit validat
 
 ### Attributes
 
-| Attribute | Allowed on | Notes |
-|-----------|-----------|-------|
-| `href` | `<a>` | Link target URL |
-| `target` | `<a>` | e.g. `_blank` |
-| `style` | Any | Only `color` and `text-align` are accepted (see below) |
+| Attribute | Purpose |
+|-----------|---------|
+| `href` | Link target URL |
+| `target` | Link opening behavior, e.g. `_blank` to open in new tab |
+| `style` | To enrich an element with some style. Only `color` and `text-align` are accepted (see below) |
 
-All other attributes are stripped and produce a validation error.
+All other attributes are either stripped or produce a validation error.
 
 ### CSS properties