Developer platform company Zed has released the public beta of Delta, a collaborative environment designed to replace GitHub's pull request model with threaded conversations between developers and coding agents. The company's co-founder and CEO Nathan Sobo announced the launch Wednesday in a blog post, arguing that pull requests — introduced by GitHub more than 15 years ago — are poorly suited to a world where agents generate code at scale. At the core of Delta is a new unit of work: the thread, which keeps the agent conversation and code changes connected so reviewers can see the reasoning behind every decision, rather than just the final diff.
The timing reflects widespread frustration with GitHub's reliability and capacity. Monthly commit volume across the platform surged from roughly 1 billion for all of 2025 to 1.4 billion per month by April, then jumped again to 2.9 billion commits each month by August. That load contributed to hundreds of incidents in the 12 months through June, including a nearly eight-hour outage in August during which web and API error rates hit around 20% at peak. Zed itself has already turned off pull requests on Delta's own repository, with 33 developers landing 570 changes to the main branch through Delta threads instead.
According to Sobo, "the thread will replace the commit or branch as the fundamental unit of software development." Each Delta thread captures a running record of an agent-assisted task, including the conversation and files being modified, and teammates can join that thread to question the agent, test revisions, and accept changes before merging them back. DeltaDB, the operation-based version control system underneath Delta, records activity at edit-level granularity — individual code changes and conversation events — rather than waiting for a developer to package work into a commit. Sobo notes that commits will still provide useful checkpoints, but they don't preserve what happens between them: the discussion with an agent, the decisions made, and the incremental edits that produce the final code.
Zed expects to leave GitHub behind within months for its own internal development, with Git storage next to move into DeltaDB and CI and releases to follow. The company's main open-source editor repository will stay on GitHub for now, where hundreds of monthly contributors already rely on the existing workflow, though those contributors can use Delta to expose the agent session behind their work while still submitting the final change through a conventional pull request. Sobo sees the next era echoing the structure of the Git era: a common technical foundation with competing developer platforms built on top. "I expect lots of viable products will compete on the agent experience, with a common infrastructure underneath," he says. Delta is available as a desktop app for macOS, Linux, and Windows, with a browser version for viewing and reviewing threads; it will stay free during the public beta, with paid plans to follow. The shift from pull requests to persistent agent threads could redefine how engineering teams track not just what changed, but why. If Delta's model catches on, version control systems may end up optimized less for human commit discipline and more for reconstructing the intelligence buried in agent-assisted workflows.