Rspamd
Rspamd 4.3 fixes SPF evaluation order and rejects weak DKIM keys, with results that change.
Comparison · Comms
Slack vs Session
A side-by-side editorial comparison of Slack and Session — release velocity, themes, recent moves, and the top alternatives to consider.
Slack vs Session: at a glance
What is Slack?
Slack now hosts any A2A agent without Slack-specific code.
Slack's developer channel is almost all agent plumbing. On 10 November Slack became an A2A (Agent2Agent) client: a team hosts its own agent, publishes an Agent Card, and Slack calls it when people talk to it, with no request URL, event handling or Slack-specific logic. This follows Slackbot skills managed through Web API methods, a Slack CLI that points coding agents to the Slack MCP server, and a new requirement that Work Objects embeds allow the slack-mcps.com frame ancestor.
What is Session?
Session ships new app versions and node upgrades while Pro stays on hold.
Session's 2026 started with a funding scare, then community support restored its runway in June. Session Pro reached a beta in app stores in September before its launch was paused in October during talks with an allied privacy ecosystem. Since then the work is infrastructure: lighter Session Node software, an update on Protocol v2, and on November 9 new iOS, Android and Desktop releases with further voluntary node upgrades and progress on a unified client.
Slack vs Session: editorial side-by-side
Slack
6.3COMMSCOLLAB
Slack now hosts any A2A agent without Slack-specific code.
◆ Current state
Slack's developer channel is almost all agent plumbing. On 10 November Slack became an A2A (Agent2Agent) client: a team hosts its own agent, publishes an Agent Card, and Slack calls it when people talk to it, with no request URL, event handling or Slack-specific logic. This follows Slackbot skills managed through Web API methods, a Slack CLI that points coding agents to the Slack MCP server, and a new requirement that Work Objects embeds allow the slack-mcps.com frame ancestor.
◆ Where it's heading
Slack is lowering the cost of putting outside agents in front of its users: first skills as code, then MCP pointers for coding agents, now a standard protocol in place of the Slack app model for agents. The platform is positioning itself as the place where agents built anywhere meet the people who use them.
◆ Prediction
Expect more A2A follow-ups, such as agents appearing in Slackbot or skills surfaces and richer Agent Card features, given how fast the agent releases have stacked up since October.
Session
5.0COMMS
Session ships new app versions and node upgrades while Pro stays on hold.
◆ Current state
Session's 2026 started with a funding scare, then community support restored its runway in June. Session Pro reached a beta in app stores in September before its launch was paused in October during talks with an allied privacy ecosystem. Since then the work is infrastructure: lighter Session Node software, an update on Protocol v2, and on November 9 new iOS, Android and Desktop releases with further voluntary node upgrades and progress on a unified client.
◆ Where it's heading
With Pro paused, Session is spending its effort on the network and the client codebase: lighter nodes, Protocol v2 with forward secrecy and post-quantum encryption, and one client for all platforms. Monetization waits on the outside talks.
◆ Prediction
Expect a Protocol v2 alpha or the unified client to be the next visible release; Pro's timing depends on talks the entries do not detail.
Alternatives to Slack and Session
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 Slack or Session.
Twilio
Twilio's voice AI stops cutting callers off mid-sentence, using its own turn-taking model.
Salesmsg
Salesmsg adds call-back requests and a one-click Emergency Stop for all outbound texts.
Element
Element 1.12.35 follows the call picture-in-picture release with one desktop storage fix.
Krisp
Krisp moves call transcripts and live captions to cloud transcription in KrispCX 2.84.4.
Misskey
Misskey 2026.11 ships: a leaner start script, and Node.js 22 no longer boots.
See all Slack alternatives → · See all Session alternatives →
Recent activity from Slack and Session
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 4d agoSlackBring your A2A agents to Slack ⚡
- 4d agoSessionDevelopment Update - New Releases and Session Node Upgrades
- 8d agoSlackWork Objects embeds require the slack-mcps.com frame ancestor
- 10d agoSlackSlack CLI 4.13 tells coding agents about Slack MCP and Skills
- 10d agoSlackSlack Skills Plugin installs in Claude Code from its own marketplace
- 12d agoSlackUpdated low-usage submission criteria for Slack Marketplace apps
- 15d agoSlackSlack CLI 4.12.0, the fourth CLI release in October
- 26d agoSessionSmaller nodes, stronger encryption: Oxen 11.7, Storage Server 2.12 and Session Router 1.1
- 1mo agoSessionSession Protocol v2: An Update on PFS, Post-Quantum and Linked Devices
- 1mo agoSessionSession is taking part in Octant's Epoch 13 privacy round
- 1mo agoSessionDevelopment Update - Stability Fixes and Network Improvements
- 2mo agoSessionSession Pro beta submitted to app stores
Frequently asked questions
What is the difference between Slack and Session?
They serve adjacent needs but don't currently overlap on shipped themes. Slack is currently shipping more aggressively (velocity 6.3 vs 5.0), 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 Slack better than Session?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Slack is currently shipping more aggressively (velocity 6.3 vs 5.0), 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 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.
What are the best alternatives to Session?
Top Session alternatives in Comms are ranked by recent ship velocity. Browse the "Session alternatives" section above for the current picks, or visit /alternatives/session for the full list with editorial commentary on each.