Cursor just pushed out Origin, a GitHub competitor, with the underlying architecture open-sourced by the Shopify CEO.

SpecWatch Beating AI News Update: Cursor has just launched its code hosting platform Origin, and Shopify CEO Tobi Lütke has open-sourced its underlying Git architecture. The project, named walgit, is a replica of Cursor's in-house developed Continuity for Origin. Tobi mentioned that he was frustrated by Shopify's internal Git system, and after reading Cursor's technical article, he developed walgit over a weekend.

The most significant change in Continuity is storing the repository's definitive data in S3 (cloud object storage), with the local Git server serving as a cache. Each push first writes to the Write-Ahead Log (WAL) to sequentially log repository changes, then updates the state through Content-Addressable Storage (CAS) to ensure no one has modified the data before submitting. This design allows for easy server replacement without the need to maintain a fixed master node and complex repository replicas relationship.

walgit has implemented this architecture as a Rust program, which can run with S3, GCS, and other object storage solutions without requiring an additional database. It also supports bundle URIs (pre-packaging large repositories for direct downloading by clones from object storage or CDN), as well as Git LFS, Web UI, API, OIDC login, and webhooks.

However, walgit primarily replicates Origin's underlying Git storage, not the entire Origin platform. Features such as PRs, issues, and a complete CI collaboration layer are yet to be developed.