Microsoft Teams Webhook Generating 400 for Adaptive Card

Question

I have a functioning webhook to a Teams channel to which I can successfully post messages. I am now trying to post an adaptive card to the webhook. Using Postman and performing a Post to https://outlook.office.com/webhook/xyz, with Content-Type set to application/json in the header and the following adaptive card set in the body.

{
  "$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
  "type": "AdaptiveCard",
  "version": "1.0",
  "speak": "Nothing to say.",
  "body": [
    {
      "type": "TextBlock",
      "text": "Hello Teams' user"
    }
  ]
}

With this I receive a HTTP 400 Bad Request and Summary or Text is required message. Does anyone know if Teams webhooks support Adaptive Cards yet or if this is an unsupported task currently?

Answer 1

The answer below is now deprecated. Please refer to this answer and this answer.

Webhooks do not yet support Adaptive Cards! We plan to add support for Adaptive Cards shortly after we release them for bots.