1 min lesson
Auto Install: a prior model builds the environment
Explain the order in "Auto Install: a prior model builds the environment", then say how you would verify the result.
Step 1 of 2
Auto Install: a prior model builds the environmentComposer 1.5 as the constructor
A coding problem isn't trainable until its repo copy actually builds, installs and runs its tests. Doing that by hand for every environment doesn't scale, so Cursor automates it with the previous model. ComposerCursor's own fast coding model, tuned for the editor and priced well below frontier models; the recommended day-to-day model for executing a plan. Press Enter for the full definition. 1.5 constructs each training environment before Composer 2Cursor's own coding model, built on the open Kimi K2.5 base as a software-engineering specialist. Cursor calls it frontier-level at coding and more cost-efficient than comparable models; Composer 2.5 has since replaced it in Cursor's model list. Press Enter for the full definition. ever trains in it.
- 1Explore. The prior model reads the repo to understand its language, build system and how it's meant to run.
- 2Propose setup. It proposes roughly ten install commands to stand the project up from a clean checkout.
- 3Write tests. It writes tests that prove the repo works, which gives the environment something to grade.
- 4Install, mock, retry. It runs the install, mocks what cannot run for real and retries until the tests pass. Only then is the environment a usable, gradeable training target.
Standing up an arbitrary repo is itself a hard agent-driven coding task, so Cursor pointed a capable existing agent at it. That turns environment creation from a manual bottleneck into something that scales with compute, which is why you can train on a large pool of real repos at all.