Microsoft Teams adaptive cards for GitHub PRs (reference)

Adaptive Card schema basics for Microsoft Teams

Microsoft Teams supports Adaptive Card schemas up to v1.5. Newer schema features (Adaptive Card v1.6 and beyond) won't render in Teams. Always set `"version": "1.5"` at the root.

PR-specific card patterns

• Header row: bold PR number + title in a TextBlock with `size: Medium`. Keep titles under 80 chars to avoid wrapping.
• Author row: ColumnSet with avatar Image (style: Person) and author/repo metadata.
• Status badge: use FactSet or coloured TextBlock to show open / draft / merged / closed.
• Action buttons: Action.OpenUrl for "View PR" and "Files changed". Action.Submit for in-Teams approve/reject (requires bot, not webhook).
• Mention chip: use the `msteams.entities` array at the root to attach mentioned-user metadata. Without this, mentions render as plain text.

Code sample: full PR card

{ "type": "AdaptiveCard", "version": "1.5", "msteams": { "entities": [ { "type": "mention", "text": "<at>Sarah Chen</at>", "mentioned": { "id": "29:1234abcd...", "name": "Sarah Chen" } } ] }, "body": [ { "type": "TextBlock", "size": "Medium", "weight": "Bolder", "text": "PR #1234: Add dark mode toggle" }, { "type": "ColumnSet", "columns": [ { "type": "Column", "width": "auto", "items": [ { "type": "Image", "url": "https://github.com/sarah.png", "style": "Person", "size": "Small" } ] }, { "type": "Column", "width": "stretch", "items": [ { "type": "TextBlock", "weight": "Bolder", "text": "<at>Sarah Chen</at>" }, { "type": "TextBlock", "spacing": "None", "text": "owner/repo · open · 3 reviewers", "isSubtle": true } ] } ] } ], "actions": [ { "type": "Action.OpenUrl", "title": "View PR", "url": "https://github.com/owner/repo/pull/1234" } ] }

Common gotchas

• Mentions render as plain text: Microsoft Teams requires the `msteams.entities` array AND the `<at>Display Name</at>` token in the body. Both are mandatory.
• Card too tall: Microsoft Teams truncates very tall cards. Keep cards under ~600px of vertical content; prefer ColumnSet over stacked items.
• Image not loading: Microsoft Teams sandbox blocks unknown image hosts. Use HTTPS URLs from trusted hosts (github.com, ik.imagekit.io).
• Action.Submit doesn't work from webhook-posted cards: Action.Submit requires a bot conversation context. From webhooks, use Action.OpenUrl instead.
• Updating the same card in place: requires the bot SDK plus the original card's conversation reference. Webhook-posted cards can't be updated in place.

How PullNotifier handles all of this

PullNotifier ships polished adaptive cards out of the box, with mention rendering, image hosting, in-place card updates, and full action button support. None of the gotchas above are your problem.