On September 29, at DevDay, OpenAI announced Space: a shared workspace inside ChatGPT where a human, the assistant, and a persistent agent called a 'dot' can all work on the same document, with a slash menu that anyone who has used Notion will recognize on sight.
What strikes me the most is that Notion itself has spent the past few months doing almost exactly the opposite move: opening its 'blocks' outward, through a CLI built for coding agents, a serverless runtime, and an API that lets Claude or Codex sit inside a workspace as a first-class collaborator rather than a plugin bolted on the side.
That reversal is striking, coming from a company that practically invented this category—block-based design wrapped in a UI so sleek it became the standard everyone else copied. A company known for building the interface nobody wanted to leave, quietly opening its own front door, is the canary in this particular coal mine: a signal that the interface itself may no longer be the control point. What's starting to matter more is the workspace underneath it—persistent, addressable, and just as writable by a model as by the person who opened it.
And it's not the only symmetry worth noticing. Notion started with the document workspace and is now inviting agents in. OpenAI started with the agent and is now building it a workspace to live in.
There's a third data point worth putting next to these two. Two weeks earlier, Anthropic folded Docs and Slides into Claude, after two years of artifacts—rendered objects that lived inside a chat window, addressable and shareable, but closer to a side effect of a conversation than to a document anyone could actually own, edit together, or hand off.
Three companies, three different starting points—one from the page, one from the agent, one from the exhaust of a conversation—arriving, within the same few weeks, at something that looks a lot like the same object: a shared, addressable block that a person and a model can both write into.
Three product visions, quietly converging. Living, for now, just a few blocks apart.
