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Comparison · Comms

Dendrite vs Slack

A side-by-side editorial comparison of Dendrite and Slack — release velocity, themes, recent moves, and the top alternatives to consider.

Dendrite vs Slack: at a glance

FeatureDendriteSlack
SectorCommsComms, Collab
Velocity score0.06.3
Sparks · 30d01
Top themesmatrix, homeserver, fork, federationagents, mcp, developer-platform, marketplace
Last editorial update1mo ago11d ago
WebsiteVisit →Visit →

What is Dendrite?

A forked, relicensed Dendrite spent its first year catching up on Matrix protocol and security debt

The window opens with the first release after forking from matrix-org/dendrite under AGPLv3, which fixed long-standing state-reset bugs and added I2P and Onion listening. What follows is a security release closing a server-side request forgery vulnerability, then a release adding room version 12 support and two MSC implementations, and finally two quick patches for unresponsiveness, v12 room joins and malformed PDUs blocking whole transactions.

Read the full Dendrite trajectory →

What is Slack?

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

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.

Read the full Slack trajectory →

Dendrite vs Slack: editorial side-by-side

D0.0

A forked, relicensed Dendrite spent its first year catching up on Matrix protocol and security debt

◆ Current state

The window opens with the first release after forking from matrix-org/dendrite under AGPLv3, which fixed long-standing state-reset bugs and added I2P and Onion listening. What follows is a security release closing a server-side request forgery vulnerability, then a release adding room version 12 support and two MSC implementations, and finally two quick patches for unresponsiveness, v12 room joins and malformed PDUs blocking whole transactions.

◆ Where it's heading

This is a fork proving it can carry a homeserver. The order is telling: license and state correctness first, then a CVE, then protocol currency with room version 12, then the operational bugs that surface once people actually run it. Several fixes carry outside contributor credits, which is the fork's clearest sign of life.

◆ Prediction

Expect continued protocol catch-up on newer MSCs and room versions plus operational fixes, since federation compatibility is the constraint that sets this project's agenda.

Slack logo
Slack
COMMSCOLLAB
6.3

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

◆ 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.

Alternatives to Dendrite and Slack

Other Comms products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either Dendrite or Slack.

See all Dendrite alternatives → · See all Slack alternatives →

Recent activity from Dendrite and Slack

Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.

  1. 12d agoSlackUpdated installation requirement for Slack Marketplace apps
  2. 13d agoSlackCLI adds app-approval status checks and custom app icons
  3. 24d agoSlackAnnouncing Slack Code
  4. 24d agoSlackAgent Sessions API replaces assistant_view, deprecated Feb 2027
  5. 1mo agoSlackAnnouncing the Slack MCP and Skills Plugin
  6. 1mo agoSlackCLI adds manifest diff and a Block Kit preview command
  7. 1y agoDendriteFixes startup crash on rooms lacking a create event
  8. 1y agoDendriteFixes v12 room joins, invites and stalled transactions
  9. 1y agoDendriteRoom version 12 support and NATS refactoring
  10. 1y agoDendriteFixes SSRF in gomatrixserverlib and speeds ACL loading
  11. 1y agoDendriteFirst release after the fork, relicensed under AGPLv3

Frequently asked questions

What is the difference between Dendrite and Slack?

They serve adjacent needs but don't currently overlap on shipped themes. Slack is currently shipping more aggressively (velocity 6.3 vs 0.0), with 1 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.

Is Dendrite better than Slack?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Slack is currently shipping more aggressively (velocity 6.3 vs 0.0), with 1 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Comms products to evaluate alongside.

What are the best alternatives to Dendrite?

Top Dendrite alternatives in Comms are ranked by recent ship velocity. Browse the "Dendrite alternatives" section above for the current picks, or visit /alternatives/dendrite for the full list with editorial commentary on each.

What are the best alternatives to Slack?

Top Slack alternatives in Comms are ranked by recent ship velocity. Browse the "Slack alternatives" section above for the current picks, or visit /alternatives/slack for the full list with editorial commentary on each.