Superhuman vs Slack
Side-by-side trajectory, velocity, and editorial themes.
Superhuman pushes calendar onto mobile and opens the inbox to AI agents via MCP.
Superhuman is a speed-focused email client now building out two fronts at once: calendar features across mobile (Android calendar, multi-day iOS views, share-availability) and an agentic layer that lets external AI tools drive the inbox through MCP and a Codex plugin. The release cadence is high and split between mobile parity and AI access.
Superhuman is turning its mail client into something AI agents can operate, with search, draft, schedule, send, and triage from Claude, ChatGPT, or Codex, while filling mobile gaps to keep parity with desktop. The bet is that being the most automatable inbox matters as much as being the fastest one.
The next likely move is more MCP-driven capability and continued mobile calendar buildout, extending the Codex/Claude/ChatGPT integration and the new Android and iPad calendar surfaces.
Slack is quietly rebuilding itself as a runtime for third-party agents.
Slack's developer platform has shifted its center of gravity from bots-that-reply to agents-that-act. The last month is dominated by agent primitives: apps can now receive the context a user is looking at, Slackbot can call external tools over MCP, and a dedicated agent messaging surface ships alongside steady CLI and Block Kit work.
Each release fills in a piece of an agent platform — context in, tools out, and a native place for agents to converse. Block Kit is gaining richer primitives (containers, data visualization) that read as the display layer for agent output. Three CLI releases in a month show the tooling keeping pace with the expanding surface.
Expect the next moves to connect these pieces: agent context feeding MCP tool calls, and Block Kit's new blocks becoming the standard way agents render results in-channel.
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