Slack API

Alert history

• Additive

  Python SDK v3.43.0 & v3.42.0 changelog additions

  Jul 8, 2026, 1:00 PM

  The Slack API changelog was updated with new Python SDK releases and features. Python SDK v3.43.0 adds a public ts property to ChatStream and AsyncChatStream and makes thread_ts optional for assistant.threads.setSuggestedPrompts. Python SDK v3.42.0 introduces authorship arguments to assistant and chat methods, highlight_type support for file upload methods, and new Block Kit block types (card, carousel, alert) plus a BlocksChunk model class. These are all additive SDK improvements that enhance functionality without breaking existing integrations.

• Additive

  New app_context_changed event for agent context

  Jul 2, 2026, 3:00 PM

  Slack is adding a new app_context_changed event and sending app_context in existing message.im and app_home_opened events. Agent apps can now automatically receive context about what a user is viewing when they send a message, enabling richer contextual interactions.

• Informational

  Changelog link updates for SDK/CLI version references

  Jul 1, 2026, 1:00 PM

  The changelog page updated documentation links for SDK and CLI version requirements, converting relative links to external GitHub/PyPI URLs with clarification for the Node Slack SDK. This is purely documentation restructuring with no change to the actual API requirements or behavior.

• Informational

  Agent messaging experience announced for Slack agents

  Jun 30, 2026, 7:00 PM

  The Slack changelog announces a new Agent messaging experience (agent_view) for apps built with Slack agents, replacing the previous Assistant messaging experience (assistant_view). This changes how agent conversations appear and interact with users, including updates to event handling, suggested prompts, and thread management. The assistant_view will be deprecated in the future, requiring existing apps to migrate to the new agent_view model.

• Informational

  Slack CLI v4.4.0 release notes added to changelog

  Jun 30, 2026, 6:00 PM

  The Slack API changelog was updated to include release notes for Slack CLI v4.4.0, which adds support for the features.agent_view app manifest property to enable the new Agent experience. This is a documentation update to the changelog page and does not affect runtime API behavior.

• Informational

  Slack CLI v4.3.0 release notes added to changelog

  Jun 18, 2026, 11:00 PM

  A new changelog entry for Slack CLI v4.3.0 was added to the changelog page, documenting three new features: the --app flag for the slack create command, availability of slack external-auth add-secret for all apps, and support for mcp_server manifest fields. This is a pure documentation/changelog update with no API behaviour changes.

• Informational

  Changelog update: Slackbot MCP Client announcement

  Jun 18, 2026, 8:00 AM

  The Slack changelog was updated to include an announcement about the new Slackbot MCP Client, which enables developers to connect MCP servers to Slack. This is a documentation/changelog update that describes a new feature for connecting external tools via the Model Context Protocol with multiple authentication methods supported.

• Breaking

  System notifications now sent from "Slack" user (USLACK) instead of Slackbot

  Jun 17, 2026, 5:00 PM

  Slack system notifications (channel membership changes, User Group updates, Slack Connect alerts, retention policy notices) are now delivered from the "Slack" system user (USLACK) instead of Slackbot, and historical Slackbot system notifications will be backfilled/moved to the new DM. Apps that filter events by Slackbot's user ID, check the username field for "Slackbot", or expect system notifications to route through Slackbot must be updated to handle USLACK instead. This is tagged as a breaking change by Slack.

• Informational

  Changelog: new Block Kit data visualization block entry

  Jun 16, 2026, 6:00 PM

  The Slack changelog was updated with a new entry documenting the availability of the data visualization block in Block Kit. This is a documentation change that informs users about new capabilities but does not alter existing API behavior or contracts.

• Informational

  Changelog updates: Java SDK, CLI releases, and API features

  Jun 4, 2026, 7:00 PM

  The Slack API changelog has been updated with announcements for Java Slack SDK v1.49.0, Slack CLI v4.2.0, and other feature releases. These are documentation-only updates describing new authorship arguments (icon_emoji, icon_url, username) for assistant.threads.setStatus and chat.startStream methods, and highlight_type support for file upload methods. This is informational and does not change documented API behavior.

• Informational

  New Block Kit data table block added to changelog

  May 20, 2026, 7:00 PM

  A new Block Kit data table block changelog entry has been added documenting availability of the data table block. This is a documentation update to the changelog page and does not introduce or change any API functionality itself.

• Informational

  Slack CLI v4.1.0 released with new features

  May 20, 2026, 8:24 AM

  The Slack API changelog has been updated with a new entry for Slack CLI v4.1.0, detailing multiple new features and improvements including a slack api <method> command for direct API calls, screen reader accessibility, environment variable support, optional OAuth scopes, and various CLI enhancements. This is a changelog update documenting released features rather than a change to the API itself.

• Additive

  New MCP Server tools added to Slack API

  May 13, 2026, 7:52 PM

  Five new tools have been added to the Slack MCP Server: Add reactions, Create a conversation/channel, List channel members, List emoji, and Read files. These are additive enhancements that extend the MCP server's capabilities without affecting existing functionality.