Zed launches Delta, multiplayer coding with agents

The team behind the Zed code editor introduced Delta, a standalone multiplayer application for writing code with AI agents and reviewing what those agents build, and sent out the first private beta invites today. Delta is built on DeltaDB, a database that replicates both the conversation and the code worktree in real time for everyone in a thread. DeltaDB works on top of the git repository a team already has: every edit and every message in the conversation is captured between commits, so teammates who never open Delta still see an ordinary git history. Where review on commit-based platforms attaches comments to snapshots that go stale as soon as code changes, Delta anchors comments to the conversation and to any line of code in the live worktree, whether an agent wrote it yesterday or a human wrote it three years ago, and it keeps that history attached to the code as it evolves. The agent itself sits in the same thread as the human reviewers, working from the same conversation and decisions, so a reviewer can ask the agent to explain or fix something instead of reconstructing intent from a diff. Teams can invite teammates into a thread with a click; threads stay private until shared, and invited participants become full collaborators who can comment in real time or pick up the work later, each getting their own locally synced copy of the code. DeltaDB also extends to the cloud: work can run on a cloud runner and keep going after a laptop is closed, and any thread can be opened in a browser through delta.dev without installing anything, running the same Rust application compiled to WebAssembly and rendered through WebGL rather than a separate JavaScript version. Delta also connects to third-party agent harnesses, starting with Claude Code, syncing a terminal session live into a Delta thread that teammates can watch, comment on and continue. The interface is designed around the volume agents produce: diffs open in full instead of collapsing, transcripts stay whole instead of being truncated or summarized, and the conversation itself behaves like a document a reviewer can navigate and comment on inline, at the level of a diff line, a plan step or a thinking block, rather than only through a text box at the bottom of a feed. Zed frames Delta as the second half of a years-long plan: first build the best place to write code, then the best place to talk about code. The company says it considered folding DeltaDB directly into Zed but chose to build DeltaDB and its first client together instead, partly because reworking Zed's foundations under its hundreds of thousands of daily users would have disrupted their existing workflows. Zed will keep being developed on its own, and DeltaDB is expected to reach it eventually, but Delta is where the underlying technology starts. More users will be invited to the beta over the coming weeks.

Key facts

Zed opened a private beta for Delta, a new multiplayer app for coding with agents and reviewing their work, sending the first invites today.
DeltaDB, the app's underlying database, replicates conversation and code worktree in real time on top of a team's existing git repository.
Review comments attach to live code and conversation rather than to fixed commit snapshots, so they stay anchored as the code changes.
Delta connects to third-party agent harnesses starting with Claude Code, and delta.dev runs the same Rust/WebAssembly/WebGL app in a browser without installation.
Zed says rebuilding its own foundations under hundreds of thousands of daily users would have been disruptive, so Delta ships as a separate application, with DeltaDB eventually planned to reach Zed itself.

Why it matters

Delta treats the agent conversation, not the diff, as the primary artifact of software work. Zed's stated bet is that once agents write most of the code, the record of why a change happened matters as much as the change itself, and that record decays fast on tools where review only ever sees a snapshot. Anchoring comments to a live worktree and a persistent conversation, with the agent present as a participant rather than a black box, is Zed's answer to that decay.

Who it affects

Developers and teams already working with coding agents, particularly Claude Code users, since Delta syncs a Claude Code terminal session live into a shared thread. It also matters to existing Zed users: the company chose to ship Delta as a separate application specifically so it would not have to rework Zed's foundations underneath its hundreds of thousands of daily users.

How to use it

Delta is invite-only for now. The first private beta invites went out the day of the announcement, and Zed says more will follow over the coming weeks; interested developers can sign up for early access. Once in, a team can use its existing git repository as-is, invite teammates into a thread with a click, connect a Claude Code session from the terminal, run work on a cloud runner, or open a shared thread in a browser at delta.dev with no install.

How solid is it

Delta comes from the team that has spent over a decade building text editors, and DeltaDB is explicitly framed as infrastructure Zed itself is expected to adopt later. The product is real and shipping to real users today, but only as a private beta with an unspecified invite pace, not a general release.

Risks and caveats

The announcement gives no pricing, no beta size or invite count, no named individual behind the post, and no timeline for when DeltaDB reaches Zed itself. Access is gated by invitation, so the practical reach of Delta beyond the beta cohort is untested and unknown for now.

“We've spent over a decade building text editors, so this is exactly the problem we know how to solve.”

— Zed team, introducing Delta