• [CHANGE] Change the default parse_mode value from MarkdownV2 to HTML for Telegram. #2981
• [CHANGE] Make api_url field optional for Telegram. #2981
• [CHANGE] Use CanonicalMIMEHeaderKey instead of TitleCasing for email headers. #3080
• [CHANGE] Reduce the number of notification logs broadcasted between peers by expiring them after (2 * repeat interval). #2982
• [FEATURE] Add proxy_url support for OAuth2 in HTTP client configuration. #3010
• [FEATURE] Reload TLS certificate and key from disk when updated. #3168
• [FEATURE] Add Discord integration. #2948
• [FEATURE] Add Webex integration. #3132
• [ENHANCEMENT] Add --web.systemd-socket flag to systemd socket activation listeners instead of port listeners (Linux only). #3140
• [ENHANCEMENT] Add enable_http2 support in HTTP client configuration. #3010
• [ENHANCEMENT] Add min_version support to select the minimum TLS version in HTTP client configuration. #3010
• [ENHANCEMENT] Add max_version support to select the maximum TLS version in HTTP client configuration. #3168
• [ENHANCEMENT] Emit warning logs when truncating messages in notifications. #3145
• [ENHANCEMENT] Add --data.maintenance-interval flag to define the interval between the garbage collection and snapshotting to disk of the silences and the notification logs. #2849
• [ENHANCEMENT] Support HEAD method for the /-/healty and /-/ready endpoints. #3039
• [ENHANCEMENT] Truncate messages with the … ellipsis character instead of the 3-dots string .... #3072
• [ENHANCEMENT] Add support for reading global and local SMTP passwords from files. #3038
• [ENHANCEMENT] Add Location support to time intervals. #2782
• [ENHANCEMENT] UI: Add 'Link' button to alerts in list. #2880
• [ENHANCEMENT] Add the source field to the PagerDuty configuration. #3106
• [ENHANCEMENT] Add support for reading PagerDuty routing and service keys from files. #3107
• [ENHANCEMENT] Log response details when notifications fail for Webhooks, Pushover and VictorOps. #3103
• [ENHANCEMENT] UI: Allow to choose the first day of the week as Sunday or Monday. #3093
• [ENHANCEMENT] Add support for reading VictorOps API key from file. #3111
• [ENHANCEMENT] Support templating for Opsgenie's responder type. #3060
• [BUGFIX] Fail configuration loading if api_key and api_key_file are defined at the same time. #2910
• [BUGFIX] Fix the alertmanager_alerts metric to avoid counting resolved alerts as active. Also added a new alertmanager_marked_alerts metric that retain the old behavior. #2943
• [BUGFIX] Trim contents of Slack API URLs when reading from files. #2929
• [BUGFIX] amtool: Avoid panic when the label value matcher is empty. #2968
• [BUGFIX] Fail configuration loading if api_url is empty for OpsGenie. #2910
• [BUGFIX] Fix email template for resolved notifications. #3166
• [BUGFIX] Use the HTML template engine when the parse mode is HTML for Telegram. #3183