Open-source Bolt alternative.

What Bolt is

Bolt (bolt.new, from StackBlitz) is a hosted AI app builder that runs in the browser: describe a product and it generates and runs a full-stack web app you can deploy. It is genuinely fast at going from prompt to a running app, with the dev environment in the browser.

It is closed-source and hosted, billed by subscription and per-token credits. Open Design is a different posture: a local-first, open-source design agent you point your own coding agent at — and the two overlap on prompt-to-UI, not on running a backend.

• Vendor: StackBlitz (bolt.new) — hosted SaaS
• Pricing: subscription + per-token credits
• Primary output: a running app, plus code export

Why teams look for a Bolt alternative

Teams start looking past Bolt when they want to own the output, control spend, and keep design as portable, version-controlled assets rather than state inside a hosted in-browser project.

• Own the output: Designs and code should live as files in your repo, not inside a hosted in-browser project.
• BYOK economics: Bring your own provider key so API spend bills to your account, instead of paying per-token credits on top of a subscription.
• Agent choice: Drive design from the coding agent you already use — Claude Code, Codex, Cursor, and more — not a single vendor-managed model.
• Open source: Apache-2.0 and self-hostable: fork it, rebrand it for your studio, or embed it in CI.

Local-first + BYOK, explained

Open Design runs a desktop app, a local daemon, and Markdown skill and design-system catalogs on your machine. No design output is forced through a vendor cloud, and your brand lives in your repo as a portable DESIGN.md file every skill respects.

You bring your own agent key. Credentials stay in local config or environment variables — Open Design never proxies them — and the API spend bills directly to you.

Open Design vs Bolt, feature by feature

Where Bolt wins: if your goal is an instant, running full-stack app in the browser with the dev environment wired up for you, Bolt does that out of the box. Open Design is design-first.

Who should pick which

Pick Bolt if:

• You want a running full-stack app from a prompt, in the browser, with zero setup.
• You want to deploy straight from the same hosted environment.
• You prefer a hosted UI and per-token credits over local files.

Pick Open Design if:

• You want design artifacts and a brand as version-controlled files.
• You want BYOK with your existing coding agent.
• You want open source you can fork, rebrand, embed in CLI, or self-host.
• You want one DESIGN.md per brand that every skill respects.

Moving a design from Bolt into Open Design

There is no automatic import from Bolt today; start design-first with a one-time brand-extraction run.

1. Install Open Design from the quickstart.
2. Open the web UI and point your agent at a Bolt project or screenshot you like.
3. Ask the agent to extract the brand into a DESIGN.md file.
4. Pick a skill and render it against your new brand.

From then on, every skill renders in your brand without re-prompting — and the files stay in your repo.

FAQ

1. 01 Is Open Design a drop-in replacement for Bolt? +

   No. Bolt ships running full-stack apps; Open Design is design-first and produces artifacts you own. They overlap on prompt-to-UI, not on running a backend.

2. 02 Can Open Design build a full app like Bolt? +

   Open Design focuses on design artifacts, prototypes, and brand systems. For an instant in-browser full-stack app, Bolt is the better fit.

3. 03 Which agent does Open Design use? +

   Your choice — BYOK with Claude Code, Codex, Cursor, Gemini, OpenCode, or Qwen. API spend bills to your account and credentials are never proxied through us.

4. 04 Is Open Design really open source? +

   Yes. It lives at github.com/nexu-io/open-design under Apache-2.0 and is self-hostable.

5. 05 Is Open Design affiliated with Bolt? +

   No. Open Design is an independent, open-source project. Bolt and bolt.new are trademarks of their owner; this is an unaffiliated comparison.