LINE Flex Messages are messages with a customizable layout. You can customize the layout freely based on the specification for CSS Flexible Box (CSS Flexbox) LINE provides a Flex Message Simulator that you can use to check the layout of your message.
LINE Flex Message is not a message type in Conversation API but it is possible to send Flex Message by overriding with Explicit Channel Message.
To do that, you can follow these steps:
- Use the LINE's Flex Message Simulator to design your message
- Copy the JSON from the simulator
- Use Transcoding API to transcode generic message format to LINE.
- Send messsage by overiding with Explicit Channel Message with the transcoded message.
Another alternative is to use another message type provided by the Conversation API. Sinch provides a Message Composer tool on the dashboard that would help you to easily build a message and visualize it in any social channels provided by the Conversation API.