Slack vs Matrix
Side-by-side trajectory, velocity, and editorial themes.
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.
Matrix grinds toward 2.0: sliding sync lands in spec, v1.19 ships long-pending features.
The tracked feed is Matrix's weekly This Week in Matrix digest plus occasional spec releases, so the signal is protocol-and-ecosystem movement rather than a single product's changelog. The substantive news this stretch: Matrix v1.19 landed encrypted room-history sharing and custom emoji (both multi-year MSCs), and Simplified Sliding Sync — a core Matrix 2.0 pillar — was accepted into the spec. Server forks (Tuwunel, Zendrite/Dendrite) are maturing with Conduit migration paths and Synapse-API compatibility.
Matrix 2.0 is the organizing arc: sliding sync moving from accepted MSC into a spec release, MatrixRTC multi-SFU calling, and now a Presence v2 effort to fix long-standing federation load. P2P Matrix has restarted with new funding. The protocol is executing on quarterly spec cadence while the client and server ecosystem catches up to the 2.0 primitives.
The next spec release should start folding sliding-sync extension MSCs (especially the E2EE ones) in behind the accepted core, and expect continued Presence v2 proposals (batching, sliding-sync integration) to follow the initial Selective Presence MSC.
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