Note: there is a page about Slack for ASF project people on infra.a.o.

Slack has three types of accounts, Member, Multi-channel guest, and Single-Channel Guest. Member and Multi-channel are pretty much the same thing, at least in cost to the ASF. Those accounts count towards our monthly usage if there are active accounts. Single-Channel guest accounts do not cost the ASF under any circumstances, however there is a limit of 5 guest accounts to 1 paid account. At the current rate, we'll never hit that limit of accounts.

  • The invite link can be used to invite anyone to the ASF Slack workspace. It's a full member invitation. Note, however, that sometimes a Slack upgrade breaks the link without warning.
  • There is no URL to invite Multi or Single Channel guests. The Slack app has links for sending guest invitations.