On this blog post, I am going to cover different options to post a Teams conversation in a Teams channel using API call.

• Using a Flow with HTTP Request trigger & Flow action
• Create an Incoming Webhook in Teams
• Graph Endpoint to create a Teams conversation

I do now see more requirements from customer to integrate Teams with different applications. These options for posting a message in a Teams channel could be to used on an External application or from a SharePoint Site using SPFx.

Create a Flow with HTTP Request trigger

Create an Instant flow with Trigger “When a HTTP request is received” a premium trigger which gets triggered to a HTTP request. This is a responsive trigger as it responds to an HTTP Request. The structure of the requests/responses that Microsoft Flow uses is a RESTful API web service known as REST. The API or HTTP post URL will be generated only after the flow is saved with at least one action.

Let’s say I would like to post a Teams conversation with @mention to a specific user and some message. In this case I will have to pass the information either in Parameters or on the body of the call. On this example we will be passing the information on the request Body

{
    "To":"ashiqf@####.onmicrosoft.com",
    "Message": "Hello from HTTP Request"
}

Copy the above sample and paste it on the popup you get after clicking on Generate Schema. The tool will automatically generate the JSON schema for you. Also jsonschema.net could be used to generate the schema

Find the generated schema below for the information email address & message which would be passed on the request body while making the POST call

Add the action “Post a message as the Flow bot to a channel”, this will create a Teams conversation on a specific channel in a Team. On the below screenshot, look at the way I am doing @mention to a user, leaving a New line & making a text appear Bold

After you save the flow, the HTTP Post URL will be generated for us to use in an external application or where ever we want. The API is not secured its anonymous. Lets now use Postman client to trigger. Don’t forget to set the headers for content-type to application/json, Information on the body & method to POST else the trigger will fail

After the Post button is clicked on Postman client which would then trigger the flow. The message on Teams channel will appear as shown below

In Postman client, there is an option to generate the code to call the API for different programming languages

As already said, the HTTP post URL is anonymous. If you would like to secure the flow actions, you could do it after the flow is triggered with some validations. If you look at the output from the Flow run for the Trigger, there is information on the field “User-Agent”, with this information you would able to add some validations

Create an Incoming Webhook in Teams for a Specific channel

Incoming webhooks could be used to create Teams Conversations on a specific channel on a team. It’s special type of Connector in Teams that provides a simple way for an external app to share content in team channels

To create a Webhook, go to the Teams channel where you would like to have the conversation posted. Click connectors

Look for Incoming Webhook from the list of connectors then click Add

Provide a Name for the webhook and click Create. Now the URL will be generated, click Done

The generated URL will be on this format, get this copied

https://outlook.office.com/webhook/24a&&546-75a8-4a24-b935-d1dbea060####@GUID/IncomingWebhook/GUID/GUID

I will now use post man to create a conversation in Teams, it has to be Post request with the information passed on the Body. The header information is not required for this POST call

{"text":"<b>Post using Incoming Webhook</b><br>Message from External Application!"}

Ref: https://docs.microsoft.com/en-us/microsoftteams/platform/webhooks-and-connectors/how-to/add-incoming-webhook

Refer the below Microsoft documentation which has some example to create an Adaptive card in teams

https://docs.microsoft.com/en-us/microsoftteams/platform/webhooks-and-connectors/how-to/connectors-using

Graph Endpoint to create a Teams conversation

There is also endpoint (REST) available in MS-Graph to post/create a Teams conversation. The time I am writing this post, its a Beta endpoint and its not recommended for production use

POST /teams/{id}/channels/{id}/messages

The ID of the Teams and the Channel ID must be passed along with the bearer Token to create a team’s conversation. To get the bearer token create a Azure AD app with API permissions for Graph to create a message. The permission could be either Delegated or Application permissions based on the requirement. There are lot of articles which covers the steps to create an App in Azure so am not going to cover those in this post.

Ref: https://docs.microsoft.com/en-us/graph/api/channel-post-messages?view=graph-rest-beta&tabs=http

Summary:

I’ve described different ways to create team’s conversation using API calls. Hope you find this post informative & useful. If you have any comments or questions, let me know on the comment section.