Link unfurling (composeExtension/queryLink) never invoked in GCC High, despite docs listing it as supported

[kpoimenidis]

Steps to reproduce

Summary:
In a GCC High tenant, a custom LOB bot-based message extension receives composeExtension/query and composeExtension/fetchTask invokes normally, but composeExtension/queryLink is never sent when a registered domain is pasted into the compose box. The identical app package works in a commercial tenant. The /entitlements payload served to the client is identical in both clouds, including the messageHandlers domain registration — so the app definition is being ingested and served correctly in GCCH, but no invoke is issued. In Teams Admin, the 'URL Previews' is enabled on the messaging policy assigned to the test user. Reproduced with multiple domains, including a self-owned domain, on manifest versions 1.14, 1.21 and 1.29. Docs list link unfurling as supported in GCC High.

Steps:

1. Register a bot in Azure Bot Service on Azure Government; configure the Teams channel and government endpoints.
2. Build an app package whose composeExtensions entry contains botId, one query command, one action command, and a messageHandlers link entry for a domain you control:

"composeExtensions": [{
  "botId": "<BOT_ID>",
  "commands": [
    { "id": "searchCmd", "type": "query", "context": ["compose", "commandBox"], ... },
    { "id": "actionCmd", "type": "action", "context": ["message"], ... }
  ],
  "messageHandlers": [
    { "type": "link", "value": { "domains": ["<your-domain>"] } }
  ]
}]

3. Upload to the GCCH Teams Admin Center, allow via app permission policy, install for a test user.
4. Send a 1:1 message to the bot → bot replies (endpoint reachable).
5. Invoke the search command from the compose box → composeExtension/query received.
6. Invoke the action command from a message → composeExtension/fetchTask received.
7. Paste https://<your-domain>/<path> into the compose box.

Already ruled out:

• Manifest / app definition — identical package works in commercial.
• Catalog ingestion — the /entitlements payload served to the client is byte-identical between commercial and GCCH, including the messageHandlers domain registration. The app definition is ingested and served correctly in GCCH; no invoke is issued from it.
• Tenant policy — AllowUrlPreviews is enabled on the messaging policy actually assigned to the test user (verified via the user's Policies tab, not just Global).
• Domain matching — reproduced with multiple domains, including self-owned. Exact hosts, no wildcards, no scheme/path in the array.
• Schema version — reproduced on manifest 1.14, 1.21 and 1.29.
• Bot/ME plumbing — query and action commands both fire invokes from the same app, same bot ID.
• App identity — fresh app id GUID; exactly one catalog entry claims the bot ID.

Expected behavior

Step 7 delivers a composeExtension/queryLink invoke to the bot's messaging endpoint.

Actual behavior

No invoke reaches the endpoint. No card, no error, no visible client behavior. Silent no-op. The same step in a commercial tenant with the identical package delivers the invoke normally.

Error details

No response

[microsoft-github-policy-service]

Hi @kpoimenidis! We will investigate and if we require further information we will reach out to you. Please use this link to escalate if you don't get replies in two working days.

Best regards, Teams Platform

[m365-agent-toolkit-assistant]

👋 Hi @kpoimenidis,

Thank you for reporting this issue! We want to let you know that:

⏱️ Our team will personally review your issue
🎯 You can expect a response within 1 business day

✨ This is an AI-generated initial response
🤖 AI-Generated Preliminary Analysis:

Classification: Bug — the reported behavior conflicts with current Microsoft Learn guidance, which says both message extensions and link unfurling are supported in GCC High, and docs state a pasted registered URL should trigger composeExtension/queryLink.

• Learn’s government cloud matrix explicitly lists Link unfurling = ✔ for GCC High.
• Learn’s link unfurling docs say pasting a registered domain URL causes an invoke named composeExtension/queryLink.
• Your repro isolates manifest, policy, domain registration, and bot reachability; query/fetchTask working in the same GCCH app makes a client/service gap more likely than app misconfiguration.
• I found no separate similar issues in the searched repos beyond this newly filed report.

What to do now:

1. Open a Microsoft support ticket for a Teams GCCH service regression/gap and reference this repro.
2. Ask docs owners to verify/correct the GCC High support matrix if engineering confirms unsupported behavior.
3. Keep a commercial-tenant validation repro handy to demonstrate parity failure.

Useful links:

• No similar issues found in the searched repos.
• https://learn.microsoft.com/microsoftteams/platform/concepts/cloud-overview#teams-app-capabilities
• https://learn.microsoft.com/microsoftteams/platform/messaging-extensions/how-to/link-unfurling

If you want, I can help draft the support escalation note.

---

Note: This is an automated first response generated by AI. A human team member will review your issue and provide a more detailed response soon. We appreciate your patience!