Why This Matters

Alertmanager is a shipped integration, but the client itself has no dedicated unit test module.

Read First

• app/services/alertmanager/client.py
• tests/services/opsgenie/test_client.py
• tests/services/vercel/test_client.py

Scope

1. Add a direct service test module for Alertmanager.
2. Follow the mocking style already used in the OpsGenie and Vercel client tests.
3. Cover the status endpoint plus one alert-listing path.

Tests / Coverage

• tests/services/test_alertmanager_client.py
• cover bearer-token auth
• cover basic-auth config
• cover HTTP error handling
• cover close() / context-manager behavior

Acceptance Criteria

• the Alertmanager client has direct tests
• no real HTTP calls are made
• auth-mode behavior is protected by tests