Updated from Slack docs, 2025/02/03

methods/chat/chat.postEphemeral.json

@@ -60,6 +60,12 @@
       "desc": "Find and link channel names and usernames.",
       "type": "boolean"
     },
+    "markdown_text": {
+      "required": false,
+      "example": "**This is bold text**",
+      "desc": "Accepts message text formatted in markdown. This argument should not be used in conjunction with blocks or text. Limit this field to 12,000 characters.",
+      "type": "string"
+    },
     "parse": {
       "required": false,
       "example": "full",
@@ -101,6 +107,7 @@
     "invalid_blocks": "Blocks submitted with this message are not valid.",
     "invalid_blocks_format": "The blocks is not a valid JSON object or doesn't match the Block Kit syntax.",
     "is_archived": "Channel has been archived.",
+    "markdown_text_conflict": "Markdown text cannot be used in conjunction with blocks or text argument.",
     "message_limit_exceeded": "Members on this team are sending too many messages. For more details, see https://slack.com/help/articles/115002422943-Usage-limits-for-free-workspaces.",
     "messages_tab_disabled": "Messages tab for the app is disabled.",
     "msg_too_long": "Message text is too long.",

methods/chat/chat.postMessage.json

@@ -54,6 +54,12 @@
       "desc": "Find and link user groups. No longer supports linking individual users; use syntax shown in Mentioning Users instead.",
       "type": "boolean"
     },
+    "markdown_text": {
+      "required": false,
+      "example": "**This is bold text**",
+      "desc": "Accepts message text formatted in markdown. This argument should not be used in conjunction with blocks or text. Limit this field to 12,000 characters.",
+      "type": "string"
+    },
     "metadata": {
       "required": false,
       "example": "{\"event_type\": \"task_created\", \"event_payload\": { \"id\": \"11223\", \"title\": \"Redesign Homepage\"}}",
@@ -154,6 +160,7 @@
     "cannot_reply_to_message": "This message type cannot have thread replies.",
     "missing_file_data": "Attempted to share a file but some required data was missing.",
     "attachment_payload_limit_exceeded": "Attachment payload size is too long.",
+    "markdown_text_conflict": "Markdown text cannot be used in conjunction with blocks or text argument.",
     "access_denied": "Access to a resource specified in the request is denied.",
     "account_inactive": "Authentication token is for a deleted user or workspace when using a bot token.",
     "deprecated_endpoint": "The endpoint has been deprecated.",

methods/chat/chat.scheduleMessage.json

@@ -48,6 +48,12 @@
       "desc": "Find and link user groups. No longer supports linking individual users; use syntax shown in Mentioning Users instead.",
       "type": "boolean"
     },
+    "markdown_text": {
+      "required": false,
+      "example": "**This is bold text**",
+      "desc": "Accepts message text formatted in markdown. This argument should not be used in conjunction with blocks or text. Limit this field to 12,000 characters.",
+      "type": "string"
+    },
     "metadata": {
       "required": false,
       "example": "{\"event_type\": \"task_created\", \"event_payload\": { \"id\": \"11223\", \"title\": \"Redesign Homepage\"}}",
@@ -110,6 +116,7 @@
     "invalid_metadata_format": "Invalid metadata format provided.",
     "invalid_metadata_schema": "Invalid metadata schema provided.",
     "invalid_time": "value passed for post_time was invalid.",
+    "markdown_text_conflict": "Markdown text cannot be used in conjunction with blocks or text argument.",
     "message_limit_exceeded": "Members on this team are sending too many messages. For more details, see https://slack.com/help/articles/115002422943-Usage-limits-for-free-workspaces.",
     "metadata_must_be_sent_from_app": "Message metadata can only be posted or updated using an app-level token.",
     "metadata_too_large": "Metadata exceeds size limit.",

methods/chat/chat.update.json

@@ -54,6 +54,12 @@
       "desc": "Find and link channel names and usernames. Defaults to none. If you do not specify a value for this field, the original value set for the message will be overwritten with the default, none.",
       "type": "boolean"
     },
+    "markdown_text": {
+      "required": false,
+      "example": "**This is bold text**",
+      "desc": "Accepts message text formatted in markdown. This argument should not be used in conjunction with blocks or text. Limit this field to 12,000 characters.",
+      "type": "string"
+    },
     "metadata": {
       "required": false,
       "example": "{\"event_type\": \"task_created\", \"event_payload\": { \"id\": \"11223\", \"title\": \"Redesign Homepage\"}}",
@@ -104,6 +110,7 @@
     "invalid_metadata_format": "Invalid metadata format provided.",
     "invalid_metadata_schema": "Invalid metadata schema provided.",
     "is_inactive": "The message cannot be edited within a frozen, archived or deleted channel.",
+    "markdown_text_conflict": "Markdown text cannot be used in conjunction with blocks or text argument.",
     "message_not_found": "No message exists with the requested timestamp.",
     "metadata_must_be_sent_from_app": "Message metadata can only be posted or updated using an app-level token.",
     "metadata_too_large": "Metadata exceeds size limit.",