Office 365 Connector migration guide for GitHub teams

What broke and why

On March 31, 2026, Microsoft retired Office 365 Connectors due to security, scalability, and flexibility concerns. URLs of the form `https://{tenant}.webhook.office.com/...` stopped accepting requests. Any GitHub webhook still pointing at one of those URLs is now silently failing.

Note: many teams discovered the breakage weeks after the retirement, when standup conversations referenced PRs that never appeared in Teams. Run the inventory step below to find every connector you rely on.

Step 1: inventory your existing GitHub-to-Teams connectors

• In each Microsoft Teams channel, open Connectors → Configured. List every Office 365 Connector that points to GitHub.
• For each GitHub repository, check Settings → Webhooks. Note any webhooks pointing at `webhook.office.com` URLs.
• If you used GitHub Actions to send notifications, grep your workflow YAML for `webhook.office.com` and related connector patterns.

Step 2: pick a migration path

The two recommended paths are PullNotifier (managed service, ~5 min total) and Power Automate Workflows (Microsoft's official path, ~30 min per repo). PullNotifier is the right call for engineering teams that want PR-specific intelligence (filtering, routing, mentions, reminders). Power Automate is the right call for organisations with mature Power Platform expertise and a "stay inside Microsoft" mandate.

Path A: PullNotifier (~5 minutes)

• Install PullNotifier from Microsoft AppSource.
• Sign in with your GitHub organisation.
• Recreate the channel mappings: for each old connector, pick the same Microsoft Teams channel and target GitHub repo in the PullNotifier dashboard.
• Send a test notification to confirm delivery.
• Disable the old Office 365 Connector and remove the broken GitHub webhook.
• Email gabriel@manta.so with subject "O365 migration" for an extended 90-day free trial.

Path B: Power Automate Workflows (~30 min per repo)

• Open the Workflows app in Microsoft Teams.
• Create a new flow with the trigger "When a webhook request is received" or pick a GitHub template.
• Add a "Compose Adaptive Card" step. See our adaptive card template at /tools/microsoft-teams-pr-notification-template.
• Add a "Post adaptive card in a chat or channel" action targeting the destination channel.
• Save the flow and copy the trigger URL.
• Add the trigger URL as a GitHub webhook in the destination repo (Settings → Webhooks → Add).
• Repeat for every repo + channel combination.

Step 3: verify and decommission old connectors

• For each repo, open a test PR and confirm the new notification arrives in Microsoft Teams.
• In each Microsoft Teams channel, remove the old Office 365 Connector configuration.
• In each GitHub repo, delete the old webhook pointing at the retired connector URL.
• Document the new setup in your team's runbook so the next person can reason about it.