0.32.1 / 2026-04-29

• [BUGFIX] dispatcher: Fix issue with dispatching to a contended route. #5179
• [BUGFIX] ui: Provide prebuilt ui assets in release. #5191
• [ENHANCEMENT] ui: Support building artifacts in containers with Docker or Podman. #5102

0.32.1-rc.0 / 2026-04-27

• [BUGFIX] dispatcher: Fix issue with dispatching to a contended route. #5179
• [BUGFIX] ui: Provide prebuilt ui assets in release. #5191
• [ENHANCEMENT] ui: Support building artifacts in containers with Docker or Podman. #5102

0.32.0 / 2026-04-08

• [CHANGE] go get github.com/prometheus/alertmanager/ui will now fail as compiled UI assets are no longer checked into the repository. Downstream builds that rely on these assets being present in the source tree must now build the UI from source. #5113
• [CHANGE] The '--enable-feature=auto-gomaxprocs' option is deprecated and will be removed in v0.33. This flag currently has no effect and can be safely removed from any startup scripts. #5090
• [CHANGE] Update internal function signatures across multiple packages. This affects any project that integrates Alertmanager code.
• [ENHANCEMENT] Add static asset caching. #5113
• [ENHANCEMENT] Reduce memory allocations through pre-sizing collections and batch allocation. #5020
• [ENHANCEMENT] Replace help with documentation in navigation bar. #4943
• [ENHANCEMENT] docs(ha): Update high availability documentation. #5136
• [ENHANCEMENT] docs: Add auth_secret_file for smtp in document. #5036
• [ENHANCEMENT] docs: Add description for global telegram_bot_token. #5114
• [ENHANCEMENT] docs: Add note about notifier timeouts. #5077
• [ENHANCEMENT] docs: Fix force_implicit_tls config field name. #5030
• [ENHANCEMENT] docs: Link community supported integrations. #4978
• [ENHANCEMENT] docs: Remove duplicate header. #5034
• [ENHANCEMENT] docs: Update mutual tls reference in high availability documentation. #5120
• [ENHANCEMENT] tracing: Use noop spans when tracing disabled. #5118
• [ENHANCEMENT] ui: Serve pre-compressed assets. #5133
• [FEATURE] Add silence annotations. #4965
• [FEATURE] Add silence logging option. #4163
• [FEATURE] Add support for multiple matcher set silences. #4957
• [FEATURE] Add the reason for notifying in dedup stage. #4971
• [FEATURE] mattermost: Flatten attachments into top-level config. #5009
• [FEATURE] mattermost: Support global webhook url. #4998
• [FEATURE] slack: Add default color from template. #5014
• [FEATURE] slack: Allow receiver to edit existing messages. #5007
• [FEATURE] template: Add dict, map and append functions. #5093
• [FEATURE] webhook: Add full payload templating support for notifier. #5011
• [BUGFIX] config: Check for empty cluster tls client config. #5126
• [BUGFIX] config: Don't crash upon reading empty config for notifier. #4979
• [BUGFIX] config: Fix ipv6 address handling in hostport.string(). #5040
• [BUGFIX] mattermost: Omit empty text field in notifications. #4985
• [BUGFIX] telegram: Send fallback message when notification exceeds character limit. #5074
• [BUGFIX] tracing: Properly shutdown tracer provider. #5131
• [BUGFIX] ui: Fix escaping for matcher values with quotes. #4862
• [BUGFIX] ui: Handle special chars in silence regex-matchers. #4942
• [BUGFIX] ui: Support utf-8 label names in matchers. #5089

0.31.1 / 2026-02-11

• [BUGFIX] docs: Fix email TLS configuration example. #4976
• [BUGFIX] docs: Add telegram bot token options to global config docs. #4999

0.31.0 / 2026-02-02

• [ENHANCEMENT] docs(opsgenie): Fix description of api_url field. #4908
• [ENHANCEMENT] docs(slack): Document missing app configs. #4871
• [ENHANCEMENT] docs: Fix max-silence-size-bytes. #4805
• [ENHANCEMENT] docs: Update expr for AlertmanagerClusterFailedToSendAlerts to exclude value 0. #4872
• [ENHANCEMENT] docs: Use matchers for inhibit rules examples. #4131
• [ENHANCEMENT] docs: add notification integrations. #4901
• [ENHANCEMENT] docs: update slack_config attachments documentation links. #4802
• [ENHANCEMENT] docs: update description of filter query params in openapi doc. #4810
• [ENHANCEMENT] provider: Reduce lock contention. #4809
• [FEATURE] slack: Add support for top-level text field in slack notification. #4867
• [FEATURE] smtp: Add support for authsecret from file. #3087
• [FEATURE] smtp: Customize the ssl/tls port support (#4757). #4818
• [FEATURE] smtp: Enhance email notifier configuration validation. #4826
• [FEATURE] telegram: Add chat_id_file configuration parameter. #4909
• [FEATURE] telegram: Support global bot token. #4823
• [FEATURE] webhook: Support templating in url fields. #4798
• [FEATURE] wechat: Add config directive to pass api secret via file. #4734
• [FEATURE] provider: Implement per alert limits. #4819
• [BUGFIX] Allow empty group_by to override parent route. #4825
• [BUGFIX] Set spellcheck=false attribute on silence filter input. #4811
• [BUGFIX] jira: Fix for handling api v3 with ADF. #4756
• [BUGFIX] jira: Prevent hostname corruption in cloud api url replacement. #4892

0.30.1 / 2026-01-12

• [BUGFIX] Fix memory leak in tracing client. #4828

0.30.0 / 2025-12-15

• [CHANGE] Don't allow calling qids with an empty ids list. #4707
• [FEATURE] Add mattermost integration. #4090
• [FEATURE] Add saturday to the first day of the week options. #4473
• [FEATURE] Add templating functions for working with urls. #4625
• [FEATURE] cluster: Allow persistent peer names. #4636
• [FEATURE] dispatch: Add start delay. #4704
• [FEATURE] provider: Add subscriber channel metrics. #4630
• [FEATURE] template: Add tojson function. #4773
• [FEATURE] Add api http metrics. #4162
• [FEATURE] Add distributed tracing support. #4745
• [FEATURE] Add names to inhibit rules. #4628
• [FEATURE] Add timeout option for pagerduty notifier. #4354
• [FEATURE] Add timeout option for slack notifier. #4355
• [FEATURE] Allow nested details fields in pagerduty. #3944
• [FEATURE] Implement phantom_threading to group email alerts into threads. #4623
• [FEATURE] gc: Report errors, but remove erroneous silences and continue. #4724
• [FEATURE] jira: Template customfields. #4029
• [FEATURE] jira: Allow configuring issue update via parameter. #4621
• [FEATURE] Slack app support. #4211
• [ENHANCEMENT] Add comment about smtp plain authentication. #4741
• [ENHANCEMENT] Add documentation about high availability. #4708
• [ENHANCEMENT] Add documentation for client_allowed_sans. #4706
• [ENHANCEMENT] Improve logging around webhook dispatch failure. #4511
• [ENHANCEMENT] Compile silence matchers when the silence is added. #4695
• [ENHANCEMENT] Fix 's/client/alerts_api/g' broken link in 0.29. #4718
• [ENHANCEMENT] Fix rocketchat_config docs. #4767
• [ENHANCEMENT] Fix: <mute_time_interval> was renamed. #4729
• [ENHANCEMENT] Improve inhibition performance. #4607
• [ENHANCEMENT] Loadsnapshot: update matcher index properly while not holding lock. #4714
• [ENHANCEMENT] Logging improvements. #4113
• [ENHANCEMENT] Move query locking back into private query function. #4694
• [ENHANCEMENT] Optimize the new inhibitor implementation for ~2.5x performance improvement. #4668
• [ENHANCEMENT] Reduce the time dispatch.group holds the mutex. #4670
• [ENHANCEMENT] Use b.loop() to simplify the code and improve performance. #4642
• [ENHANCEMENT] Remove duplicate slice during silences query. #4696
• [ENHANCEMENT] Silences: optimize incremental mutes queries via a silence version index. #4723
• [ENHANCEMENT] Update description for filter param in openapi. #4775
• [BUGFIX] Add new behavior to avoid races on config reload. #4705
• [BUGFIX] config: Fix duplicate header detection for all case variants. #2810
• [BUGFIX] marker: Stop state leakage from aggregation groups. #4438
• [BUGFIX] Fix pprof debug endpoints not working with --web.route-prefix. #4698
• [BUGFIX] Set context timeout for resolvepeers. #4343

0.30.0-rc.0 / 2025-12-10

• [CHANGE] Don't allow calling qids with an empty ids list. #4707
• [FEATURE] Add mattermost integration. #4090
• [FEATURE] Add saturday to the first day of the week options. #4473
• [FEATURE] Add templating functions for working with urls. #4625
• [FEATURE] cluster: Allow persistent peer names. #4636
• [FEATURE] dispatch: Add start delay. #4704
• [FEATURE] provider: Add subscriber channel metrics. #4630
• [FEATURE] template: Add tojson function. #4773
• [FEATURE] Add api http metrics. #4162
• [FEATURE] Add distributed tracing support. #4745
• [FEATURE] Add names to inhibit rules. #4628
• [FEATURE] Add timeout option for pagerduty notifier. #4354
• [FEATURE] Add timeout option for slack notifier. #4355
• [FEATURE] Allow nested details fields in pagerduty. #3944
• [FEATURE] Implement phantom_threading to group email alerts into threads. #4623
• [FEATURE] gc: Report errors, but remove erroneous silences and continue. #4724
• [FEATURE] jira: Template customfields. #4029
• [FEATURE] jira: Allow configuring issue update via parameter. #4621
• [FEATURE] Slack app support. #4211
• [ENHANCEMENT] Add comment about smtp plain authentication. #4741
• [ENHANCEMENT] Add documentation about high availability. #4708
• [ENHANCEMENT] Add documentation for client_allowed_sans. #4706
• [ENHANCEMENT] Improve logging around webhook dispatch failure. #4511
• [ENHANCEMENT] Compile silence matchers when the silence is added. #4695
• [ENHANCEMENT] Fix 's/client/alerts_api/g' broken link in 0.29. #4718
• [ENHANCEMENT] Fix rocketchat_config docs. #4767
• [ENHANCEMENT] Fix: <mute_time_interval> was renamed. #4729
• [ENHANCEMENT] Improve inhibition performance. #4607
• [ENHANCEMENT] Loadsnapshot: update matcher index properly while not holding lock. #4714
• [ENHANCEMENT] Logging improvements. #4113
• [ENHANCEMENT] Move query locking back into private query function. #4694
• [ENHANCEMENT] Optimize the new inhibitor implementation for ~2.5x performance improvement. #4668
• [ENHANCEMENT] Reduce the time dispatch.group holds the mutex. #4670
• [ENHANCEMENT] Use b.loop() to simplify the code and improve performance. #4642
• [ENHANCEMENT] Remove duplicate slice during silences query. #4696
• [ENHANCEMENT] Silences: optimize incremental mutes queries via a silence version index. #4723
• [ENHANCEMENT] Update description for filter param in openapi. #4775
• [BUGFIX] Add new behavior to avoid races on config reload. #4705
• [BUGFIX] config: Fix duplicate header detection for all case variants. #2810
• [BUGFIX] marker: Stop state leakage from aggregation groups. #4438
• [BUGFIX] Fix pprof debug endpoints not working with --web.route-prefix. #4698
• [BUGFIX] Set context timeout for resolvepeers. #4343

0.29.0 / 2025-11-01

• [FEATURE] Add incident.io notifier. #4372
• [FEATURE] Add monospace message formatting. #4362
• [FEATURE] Add ability to customize interval for maintenance to run. #4541
• [ENHANCEMENT] Update Jira notifier to support both Jira cloud API v3 and Jira datacenter API v2. #4542
• [ENHANCEMENT] Increase mixin rate intervals for alert FailedToSendAlerts. #4206
• [ENHANCEMENT] Make /alertmanager group writable in docker image. #4469
• [BUGFIX] Fix logged notification count on error in notify. #4323
• [BUGFIX] Fix docker image permissions path. #4288
• [BUGFIX] Fix error handling in template rendering for Telegram. #4353
• [BUGFIX] Fix duplicate other in error messages for config. #4366
• [BUGFIX] Fix logic that considers an alert reopened in Jira. #4478
• [BUGFIX] Fix Jira issue count #4615

0.29.0-rc.1 / 2025-10-12

• [FEATURE] Add incident.io notifier. #4372
• [FEATURE] Add monospace message formatting. #4362
• [FEATURE] Add ability to customize interval for maintenance to run. #4541
• [ENHANCEMENT] Update Jira notifier to support both Jira cloud API v3 and Jira datacenter API v2. #4542
• [ENHANCEMENT] Increase mixin rate intervals for alert FailedToSendAlerts. #4206
• [ENHANCEMENT] Make /alertmanager group writable in docker image. #4469
• [BUGFIX] Fix logged notification count on error in notify. #4323
• [BUGFIX] Fix docker image permissions path. #4288
• [BUGFIX] Fix error handling in template rendering for Telegram. #4353
• [BUGFIX] Fix duplicate other in error messages for config. #4366
• [BUGFIX] Fix logic that considers an alert reopened in Jira. #4478