The problem isn't the agent. It's that auth-to-billing-to-gating is genuinely hard to wire, and there's no machine-readable spec for how to do it.

Corral is an open-source CLI (MIT) that gives your agent a spec it can read (llms.txt), then scaffolds auth + Stripe billing into your existing project. It detects your framework (Express, Next.js, Hono, Fastify, and 13+ more), embeds into your existing server (doesn't create a new one), and generates working components: profile page, admin dashboard, plan gating, Stripe checkout, usage metering. One YAML config file controls everything.

The agent workflow is 9 commands. Every command supports --json. Errors include a "fix" field. Exit 0 means deploy-ready.

I hardened this across 10 framework/DB combos with blind agent tests: 3 AI models, 3 rounds each, then a 10-agent fleet. Found and fixed real edge cases like Express 4 vs 5 route patterns, Vite proxy ordering, and agents creating duplicate servers instead of embedding into existing ones.

To try it, paste this into any AI coding agent:

  Read: https://llama-farm.github.io/corral/llms.txt
  Add auth and Stripe billing to my app.

GitHub: https://github.com/llama-farm/corral npm: npx create-corral init Docs: https://llama-farm.github.io/corral/