Rspamd
Rspamd 4.3 fixes SPF evaluation order and rejects weak DKIM keys, with results that change.
Comparison · Comms
Shortwave vs Slack
A side-by-side editorial comparison of Shortwave and Slack — release velocity, themes, recent moves, and the top alternatives to consider.
Shared themes:mcp
Shortwave vs Slack: at a glance
What is Shortwave?
Shortwave keeps folding autonomy into the inbox, one AI action at a time.
Shortwave has moved decisively from an AI-assisted email client to an inbox that acts on the user's behalf. The assistant reads, drafts, organizes, and — via the Tasklet integration — triggers automated workflows across thousands of apps, with its work surfaced inside Shortwave rather than buried in Gmail. Every release since late 2024 has pushed more of the email workflow out of the user's hands and into the model's.
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.
Shortwave vs Slack: editorial side-by-side
Shortwave
0.0COMMS
Shortwave keeps folding autonomy into the inbox, one AI action at a time.
◆ Current state
Shortwave has moved decisively from an AI-assisted email client to an inbox that acts on the user's behalf. The assistant reads, drafts, organizes, and — via the Tasklet integration — triggers automated workflows across thousands of apps, with its work surfaced inside Shortwave rather than buried in Gmail. Every release since late 2024 has pushed more of the email workflow out of the user's hands and into the model's.
◆ Where it's heading
The direction is a steadily widening action surface: MCP connectors to external tools, AI Memories, voice, and now trigger-based automation all frame email as an agent runtime rather than a reading pane. Model choices track the frontier closely — Claude 3.7 to Sonnet 4 to the 4.6 family — keeping capability tied to whatever the best available model can do. The team ships broadly across web, desktop, iOS, and Android each cycle.
◆ Prediction
The next moves most likely deepen autonomous execution — more trigger types and tighter loops where the assistant acts with less confirmation — rather than adding new surface features.
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.
Alternatives to Shortwave 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 Shortwave or Slack.
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 Shortwave alternatives → · See all Slack alternatives →
Recent activity from Shortwave and Slack
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 4d agoSlackBring your A2A agents to Slack ⚡
- 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
- 8mo agoShortwaveUpgraded to Claude Sonnet & Opus 4.6
- 10mo agoShortwaveFully automate your email with Tasklet 🔗 ⚡
- 1y agoShortwaveEnhanced AI performance & collaboration
- 1y agoShortwaveIntegrate the AI with all your apps 🔌 ⚡
- 1y agoShortwaveTalk to your inbox 🎙️
- 1y agoShortwaveOrganize your inbox with AI ✨
Frequently asked questions
What is the difference between Shortwave and Slack?
Both compete on the same themes — mcp — within Comms. 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 Shortwave 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 Shortwave?
Top Shortwave alternatives in Comms are ranked by recent ship velocity. Browse the "Shortwave alternatives" section above for the current picks, or visit /alternatives/shortwave 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.