Rspamd
Rspamd 4.3 fixes SPF evaluation order and rejects weak DKIM keys, with results that change.
Comparison · Comms
Proton Bridge vs Slack
A side-by-side editorial comparison of Proton Bridge and Slack — release velocity, themes, recent moves, and the top alternatives to consider.
Proton Bridge vs Slack: at a glance
What is Proton Bridge?
Proton Bridge v3.27.2 adds support for the oo7 keyring on Linux.
Proton Bridge's releases in 2026 have been almost entirely maintenance: monthly vulnerability patches, Go toolchain bumps, IMAP RFC-compliance fixes and recovery from corrupted sync state files. v3.27.2 adds one item, support for the oo7 keyring service, a Rust-based Secret Service implementation used on newer Linux desktops.
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.
Proton Bridge vs Slack: editorial side-by-side
Proton Bridge
2.5COMMS
Proton Bridge v3.27.2 adds support for the oo7 keyring on Linux.
◆ Current state
Proton Bridge's releases in 2026 have been almost entirely maintenance: monthly vulnerability patches, Go toolchain bumps, IMAP RFC-compliance fixes and recovery from corrupted sync state files. v3.27.2 adds one item, support for the oo7 keyring service, a Rust-based Secret Service implementation used on newer Linux desktops.
◆ Where it's heading
Bridge remains a stable compatibility layer rather than a growing product. The small additions that do land are about running cleanly on more desktop environments.
◆ Prediction
Expect the next monthly security patch release; the entries show no sign of feature work.
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 Proton Bridge 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 Proton Bridge 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 Proton Bridge alternatives → · See all Slack alternatives →
Recent activity from Proton Bridge and Slack
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 4d agoSlackBring your A2A agents to Slack ⚡
- 7d agoProton Bridgev3.27.2: support for the oo7 keyring service
- 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
- 1mo agoProton Bridgev3.27.1: recover from corrupted sync state
- 2mo agoProton Bridgev3.27.0: August security patches and IMAP fixes
- 2mo agoProton Bridgev3.26.0: July security patches and cleanup
- 5mo agoProton Bridgev3.25.0: clearer errors, legacy updater removed
- 6mo agoProton Bridgev3.24.2: new Go base image
Frequently asked questions
What is the difference between Proton Bridge and Slack?
They serve adjacent needs but don't currently overlap on shipped themes. Slack is currently shipping more aggressively (velocity 6.3 vs 2.5), 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 Proton Bridge 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 2.5), 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 Proton Bridge?
Top Proton Bridge alternatives in Comms are ranked by recent ship velocity. Browse the "Proton Bridge alternatives" section above for the current picks, or visit /alternatives/proton-bridge 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.