How Stripe Built AI Agents That Write 1,000+ Pull Requests a Week

Stripe's internal AI coding agents, called 'minions', autonomously merge over 1,000 pull requests weekly through a six-layer system architecture. The system combines an open-source agent fork with Stripe-specific infrastructure: Slack-initiated workflows, pre-fetched context via MCP (400+ tools), isolated dev boxes, hybrid deterministic-LLM execution, tiered validation (linters, selective CI tests, capped retries), and standard PR workflows. The key insight is that existing developer productivity tools work equally well for AI agents, with the real engineering challenge being the harness around the agent rather than the agent itself.