如何让自定义侧载Microsoft Teams应用显示Compose Extension省略号按钮？

Let’s walk through targeted fixes for this issue—since your tabs and bot are working, we can narrow down the problem to specific Messaging Extension configuration details:

• Verify your manifest.json composeExtensions structure thoroughly
  It’s not enough to just set the botId—you need a valid commands array with the right context to trigger the ellipsis button. Ensure your configuration includes these critical elements:

  "composeExtensions": [
    {
      "botId": "<your-exact-bot-id>",
      "commands": [
        {
          "id": "unique-command-identifier",
          "title": "Your Command Name",
          "description": "Briefly explain what this command does",
          "context": ["compose"] // This line tells Teams to show the button in the compose box
        }
      ]
    }
  ]
  

  Double-check that the botId matches exactly (it’s case-sensitive!) the ID from your Azure AD bot registration—even a single typo will prevent the button from appearing.

• Confirm your bot’s registration and endpoint health
  Messaging Extensions rely on the bot accepting specific Teams requests, even if the bot works for other features:

  • Make sure your bot’s messaging endpoint is publicly accessible and returns a 200 OK response for validation requests (you can test this with tools like curl or Postman).
  • In your Azure bot resource, navigate to the "Channels" tab and confirm Microsoft Teams is enabled and properly configured.

• Refresh your app and clear Teams cache
  Cached old manifest data is a common culprit:

  1. Delete the sideloaded app from Teams completely.
  2. Regenerate your app’s ZIP package to ensure it includes the updated manifest.json.
  3. Clear Teams cache:
     • Windows: Delete the folder at %appdata%\Microsoft\Teams
     • Mac: Delete ~/Library/Application Support/Microsoft/Teams
  4. Restart Teams and re-sideload your app.

• Test with an updated Teams client and different environment
  Outdated Teams versions can have bugs with Messaging Extension rendering. Update to the latest desktop or web Teams client, then test in a separate environment (e.g., web Teams vs. desktop, or a different tenant if available) to rule out client-specific issues.

• Use Teams dev tools to spot errors
  Open Teams’ developer tools (Ctrl+Shift+I on desktop, or your browser’s dev tools for web) and check the Console tab for errors. Look for messages about manifest parsing failures, bot connection issues, or permission gaps—these will directly point you to the root problem.

内容的提问来源于stack exchange，提问作者Thomas Aylott