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COMMSCOLLAB
Velocity6.3

Business communication and collaboration platform

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Slack raises the Marketplace bar back to ten installs while the agent platform consolidates.

agentsmcpdeveloper-platformmarketplacedeprecationsdk-modernization
◆Current state
Slack's developer platform runs two tracks. The agent build-out has produced a spark roughly every two weeks since June — MCP client, a skills plugin targeting Claude Code and Cursor, and Slack Code — and now has a consolidation date attached: assistant_view is deprecated in February 2027, replaced by an Agent Sessions API. The second track is platform administration and tooling, and this window belongs to it: Marketplace submissions again require at least ten installed active workspaces, held throughout the review, after a period at a lower temporary threshold. The CLI has shipped three times since late July.
◆Where it's heading
The install requirement moving back up is a distribution decision arriving in the middle of a platform push, and the two point the same way. Slack is making it easier to build agents and harder to list one, which favours developers who already have distribution — existing workspace tools and vendors — over a new app hoping the Marketplace supplies its first users. Combined with the assistant deprecation and the Agent Sessions API, the platform is narrowing on one agent surface and one class of builder rather than widening the funnel.
◆Prediction
The threshold is described as a return from a temporary lower bar rather than a new policy, so the open question is what replaces the Marketplace as the discovery path for an app that cannot reach ten workspaces on its own. These entries do not answer it.

◆Recent moves

  1. 15d ago

    Updated installation requirement for Slack Marketplace apps

    Marketplace submissions again require ten or more installed active workspaces, sustained through the whole review, up from a temporary lower threshold. It is a distribution gate rather than a capability change, but it decides which of the agents Slack has spent the summer enabling ever reach a listing.

    View source ↗
  2. 16d ago

    CLI adds app-approval status checks and custom app icons

    The CLI picks up app-approval status checks and custom app icons. Tooling continues to track the platform shift from underneath, adding the administrative commands a builder needs once approval is a gate that matters.

    View source ↗
  3. 27d ago

    Announcing Slack Code

    ⚡ SPARK

    The release that made the deprecation inevitable: a surface for work that outlives a single reply. The Agent Sessions API announced the same day is the plumbing this needs, and the assistant path is being retired to avoid maintaining two messaging models against it.

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  4. 27d ago

    Agent Sessions API replaces assistant_view, deprecated Feb 2027

    The Agent Sessions API replaces assistant_view, giving a conversation a status, a title and a stop button, with assistant_view deprecated in February 2027 and a compatibility bridge in between. This is the consolidation the Slack Code launch made inevitable.

    View source ↗
  5. 1mo ago

    Announcing the Slack MCP and Skills Plugin

    ⚡ SPARK

    Packaging platform knowledge as an agent plugin rather than documentation, aimed at named hosts. The CLI work since has followed the same premise, down to recommending that plugin to Claude Code users on project creation.

    View source ↗
  6. 1mo ago

    CLI adds manifest diff and a Block Kit preview command

    Manifest diff and a Block Kit preview command arrive in the CLI. Both are the kind of check a developer runs before submitting — useful now that a submission has an install threshold to hold through review.

    View source ↗