Proto team built a Vibe agent that autonomously writes RSpec tests for Rails
Applied AI's Proto team built an autonomous agent on top of Mistral's open-source coding assistant Vibe that reads Rails code, generates or improves RSpec tests, validates style and coverage (via RuboCop and SimpleCov), and runs in CI/CD with no human intervention, operating in parallel across files. They used repository-level AGENTS.md for context and separate file-type 'skills' to improve test completeness and quality, raising their internal quality score from 0.68 to 0.74.