BM Builder is an AI App Studio you run locally. A simulated executive team brainstorms your idea, writes the full plan, then Claude Code autonomously builds and QA's it — at $0 on your Claude subscription.
Free download · runs locally · Apache-2.0 open source · plan with Claude or OpenAI · build with Claude Code
BM Builder is for individuals — indie makers, solo founders, and tinkerers — who want to build small-to-medium tools and run them on their own computer.
You don't need another chatbot that spits out a snippet and a shrug. You need scope, a real plan, actual files, and something that runs.
Most AI tools hand you a prompt box. BM Builder hands you a product team — one that asks the right questions, writes the spec, and ships the build.
Describe your idea in plain English. The team — CEO, CTO, CMO, PM, QA, and a Skeptic — asks sharp, non-overlapping questions and shows a live readiness score so you know when it's ready to plan.

It authors a real PRD, tech spec, data model, and a prioritized roadmap you can drag, edit, and trim. The CEO assigns the right AI model to each role — and you can override any pick.

Claude Code autonomously writes, runs, and fixes the project on your subscription — watch the live Kanban move from To do → In Development → In QA → Done. No API bill.

Review the result, run a visual front-end QA, and follow clear next steps to see it run and deploy when you're ready.

CEO, CTO, CMO, PM, QA and a Skeptic each play their part — strategy, architecture, UX, delivery, and red-teaming.
Every project becomes a folder: PRD, plan, tech spec, data model, roadmap, red-team review, and generated source.
Claude Code builds, runs, and fixes the project on your Claude subscription — the heavy lifting doesn't burn API credits.
Set each planning agent to the Claude subscription, the Anthropic API, or OpenAI — per agent. The CEO picks the right model within your choice; the autonomous build itself runs on Claude Code.
Edit the plan, override the model picks, reorder the roadmap, and sign off only when you're happy.
Apache-2.0 licensed and yours to shape — fork it, tweak the agent prompts, add roles, or wire in your own tools.
Hover any shot and click the to open it full size.




BM Builder is Apache-2.0 licensed and runs as a local app. Get it from GitHub, then start it with one command — a .\run.ps1 / ./run.sh launcher is included.
No sign-up · free forever · a GitHub ⭐ helps others find it.
We design and ship tailored AI systems, agents, and automations for businesses. BM Builder is a small taste of what we build. If you want a custom AI tool, an agentic workflow, or AI woven into your product — let's talk.
The tool is free. Builds run at $0 on your Claude subscription. An Anthropic or OpenAI API key is optional and metered by your provider.
Web apps, CLIs, APIs, scripts, and prototypes — it plans to the stack that fits your idea, then generates runnable source.
Individuals — indie makers, solo founders, and tinkerers — who want to build small-to-medium tools and run them on their own computer.
The AI team — brainstorming and planning — works with Claude (subscription or API) or OpenAI / OpenAI-compatible endpoints, chosen per agent in Settings. The autonomous build & QA step runs on Claude Code — that's what makes builds $0 on your Claude subscription, so a Claude subscription is needed for that step.
No to get started. A little helps for tweaks — and there's a one-click "Open in VS Code" handoff if you want to take it further.