slack-go/slack v0.21.0

on GitHub

Breaking changes

Removed APIs

• IM struct removed — Use Conversation instead. IsUserDeleted has been moved there.
• Info.GetBotByID, GetUserByID, GetChannelByID, GetGroupByID, GetIMByID removed — These were deprecated and returned nil unconditionally. Remove any calls to them.

Signature changes

• ListReactions now uses cursor-based pagination — Returns ([]ReactedItem, string, error) instead of ([]ReactedItem, *Paging, error). ListReactionsParameters replaces Count/Page with Cursor/Limit.

  // Before
  items, paging, err := api.ListReactions(params)
  // After
  items, nextCursor, err := api.ListReactions(params)

• ListStars/GetStarred now use cursor-based pagination — Same pattern: returns string (next cursor) instead of *Paging. StarsParameters replaces Count/Page with Cursor/Limit.

• GetAccessLogs now uses cursor-based pagination — Same pattern: returns string (next cursor) instead of *Paging. AccessLogParameters replaces Count/Page with Cursor/Limit.

• Ack() and Send() now return error (Socket Mode) — Large payloads (≥20KB) that Slack silently dropped are now rejected with an error. Existing call sites that ignore the return value still compile.

Type changes

• WebhookMessage.UnfurlLinks / UnfurlMedia → *bool — Required to distinguish "omit" from "false".

  // Before
  msg := slack.WebhookMessage{UnfurlLinks: true}
  // After
  t := true
  msg := slack.WebhookMessage{UnfurlLinks: &t}

• User.Has2FA → *bool — nil means absent/unknown (bot tokens), false means explicitly disabled.

Behavior changes

• MsgOptionBlocks() with no arguments now sends blocks=[] — Previously a silent no-op. If you relied on that, remove the option entirely.
• admin error strings now start with lowercase — If you match error content in your code, update your comparisons.

Added

• admin.teams.settings.* API support — Full suite: AdminTeamsSettingsInfo, SetDefaultChannels, SetDescription, SetDiscoverability, SetIcon, SetName ([#960])
• BlockFromJSON / MustBlockFromJSON — Create blocks from raw JSON strings, enabling direct use of output from Slack's Block Kit Builder ([#1497])
• GetOpenIDConnectUserInfo — Returns identity info via openid.connect.userInfo ([#967])
• OAuthOptionAPIURL for package-level OAuth functions — Override the Slack API URL for testing ([#744])
• HTTP response headers — Access Slack response headers (X-OAuth-Scopes, X-Ratelimit-*, etc.) via OptionOnResponseHeaders callback ([#1076])
• API warning callbacks — Register OptionWarnings(func(warnings []string)) to receive Slack deprecation notices ([#1540])
• DNDOptionTeamID — Pass team_id to GetDNDInfo/GetDNDTeamInfo, required after workspace migration ([#1157])
• UpdateUserGroupMembersList — Accepts []string instead of comma-separated string ([#1172])
• SetUserProfile — Set multiple profile fields in a single API call ([#1158])
• RTM events — user_status_changed, user_huddle_changed, user_profile_changed, sh_room_join, sh_room_leave, sh_room_update, channel_updated ([#1541], [#858])
• Socket Mode handlers — HandleShortcut, HandleViewSubmission, HandleViewClosed for Level 3 dispatch by CallbackID ([#1161])
• New fields — Username on User ([#1218]), Blocks/Attachments/Files/Upload on AppMentionEvent ([#961]), Blocks on MessageEvent ([#1257]), IsConnectorBot/IsWorkflowBot on User, GuestInvitedBy on UserProfile, CacheTS/EventTS on UserChangeEvent

Fixed

• UnknownBlock round-trip data loss — Unrecognized block types now preserve their full JSON through unmarshal/marshal cycles
• WorkflowButtonBlockElement missing from UnmarshalJSON — Plus missing multi_*_select and file_input cases ([#1539])
• NewBlockHeader nil pointer dereference — Passing a nil text object no longer panics ([#1236])
• ValidateUniqueBlockID false positives — Empty block_id strings no longer flagged as duplicates ([#1184])
• Socket Mode: large Ack payloads silently failing — Now uses 32KB write buffer and rejects payloads ≥20KB with an error ([#1196])

Deprecated

• slackevents.ParseActionEvent — Cannot parse block_actions. Use slack.InteractionCallback with json.Unmarshal instead ([#596])
• slackevents.MessageAction, MessageActionEntity, MessageActionResponse — Legacy interactive_message types only

Full Changelog: v0.20.0...v0.21.0