Cursor Drops Composer 3, a 1.5T-Parameter Model Trained on SpaceX's Supercomputer
Cursor's Compile keynote dropped three major launches: a GitHub rival, a mobile app, and a 1.5-trillion-parameter model being trained with SpaceX's Colossus supercomputer
- SpaceX acquired Cursor for $60B in all-stock, the largest VC-backed startup acquisition ever, expected to close Q3 2026.
- Composer 3 announced: 1.5T+ parameter model trained from scratch on SpaceX's Colossus (1M H100-equivalent GPUs), targeting Claude Opus / GPT-5.5 class.
- Origin launched: a GitHub competitor built for AI agents, with 296K clones/hour and AI-powered merge conflict resolution; waitlist open, ships fall 2026.
- Cursor Mobile iOS beta lets developers prompt agents and remotely control desktop sessions from their phone.
- SpaceX used fresh IPO stock (priced at $135, trading near $200 days later) to fund the deal without spending operating cash.
- Cursor's market share fell from ~41% to ~26% in under a year despite revenue surpassing $4B ARR, signaling intense competition from Claude Code and OpenAI Codex.
At its inaugural Compile conference in San Francisco, Cursor came out swinging with three announcements that collectively reframe what the company is building. The headline-grabber was already known to insiders: SpaceX had exercised its option to acquire Cursor (officially Anysphere Inc.) in a $60 billion all-stock deal. But the product announcements made clear that Cursor isn't waiting around to be absorbed. It's building infrastructure.
The Three Announcements
The Compile keynote surfaced three distinct launches, each targeting a different layer of the development stack:
- Origin -- a Git hosting platform built from the ground up for AI agents, positioned as a direct GitHub competitor
- Composer 3 -- a new frontier model being trained from scratch on SpaceX's Colossus supercomputer, with no third-party base model underneath it
- Cursor Mobile -- an iOS beta that lets developers prompt agents, edit code, and remotely control desktop Cursor sessions from their phone
Origin: When GitHub Wasn't Built for This
At the conference, Cursor announced Origin, a code storage and Git hosting platform fundamentally redesigned to treat AI agents as first-class citizens. Built on re-architected technology from its December 2025 acquisition of Graphite, Origin is purpose-built for the high-frequency cloning, pushing, and parallel branch merge conflicts that characterize AI agent workflows.
Performance metrics include 296,000 clones per hour and sub-400-millisecond global synchronization latency. On the main screen at Compile, Cursor displayed roughly 81,000 pushes and 22.6 commits per second on a single repository, with automatic failover completed within 10 milliseconds. The key insight here is that when agents are generating commits at machine speed, the bottleneck shifts from the developer to the infrastructure. GitHub was built for humans typing. Origin is built for fleets.