Runner Builder
Runner Builder is a free, open-source AI app builder under AGPL-3.0. It writes Vite plus React plus Tailwind web apps and Expo plus React Native mobile apps, previewed live next to the chat, using the user's own Codex CLI, Claude Code or Gemini CLI subscription. Every turn is a Git commit for instant revert. One caveat: AGPL-3.0 copyleft applies to any hosted fork.
What does Runner Builder do?
Runner Builder describes itself as "Describe an app in a chat, an agent writes it to disk, and you watch it come to life in a live preview next to the conversation." It opens a chat panel, a file tree and a live preview in one window; the user types a change in plain English, the agent writes the files to disk, and the preview reloads.
Three agent backends are supported, each using the user's own subscription: Codex CLI, Claude Code, and Gemini CLI. The project is local-first, so code stays on the machine. Web apps are Vite plus React plus Tailwind; mobile apps are Expo and React Native, with a phone preview through Expo Go and a path to the App Store and Google Play. Git is used as the history ledger, with every turn committed so a user can revert to any earlier state.
Key facts
- Licence: GNU AGPL-3.0; commercial licences available from Runner AI for closed-source hosting.
- Code form: local-first desktop app that manages a project folder on disk.
- Web output: Vite plus React plus Tailwind.
- Mobile output: Expo plus React Native, with Expo Go on a phone for preview and Store submission.
- Agent backends: Codex CLI, Claude Code, Gemini CLI, each using the user's own subscription.
- Version control: Git-backed history; every turn is a commit and revert is instant.
- Live preview: hot module reloading inside the app window.
- Team: workspaces with roles (viewer, editor, owner).
- GitHub: integration with a pull-request workflow.
- Working today, per the README: dashboards, chat-to-code generation, live preview, mobile apps, GitHub integration, team features.
- Known limits: file attachments, password recovery, test coverage.
What does it replace, and where does it fall short?
Runner Builder replaces Lovable for teams that want the chat-to-app loop on their own machine and are already paying for a Codex, Claude Code or Gemini CLI subscription, so no extra model fee is charged.
Where it falls short: AGPL-3.0 copyleft means a hosted fork that charges end users has to publish its source. The runtime is tied to the user's coding-agent subscription: a free trial does not come with a model. The known-limits list in the README names file attachments, password recovery and test coverage as rough edges. The mobile path uses Expo, so bare React Native projects and native iOS or Android code are outside the standard template. There is no built-in database, authentication or storage service: Runner writes code the user then wires to their own services (see Chef if that matters).
How does Runner Builder run?
Install from the Releases page for macOS, Windows or Linux. On first launch, sign in to a workspace (local) and pick an agent backend: Codex CLI, Claude Code or Gemini CLI. The agent uses the user's existing subscription, and no central agent server is involved. A project folder on disk holds the generated code and a .git directory for the history.
For web apps, the preview runs a Vite dev server inside the app. For mobile apps, Runner starts Expo and shows a QR code; a reader with Expo Go on a phone scans the QR code and sees the live app. Every chat turn is committed to Git, and a "rewind" command resets the working tree to any earlier commit.
Who is Runner Builder for?
A reader who wants the Lovable-style chat-to-app loop on their own laptop, who is already paying for a Codex, Claude Code or Gemini CLI subscription, and who ships both web and mobile. A reader who wants a one-click hosted service should use Lovable itself. A reader who needs a built-in database and auth from the chat should look at Chef. A reader who wants a visual designer should look at Onlook.
What limits does the README state?
- AGPL-3.0 applies to the source; commercial closed-source hosting needs a separate licence from Runner AI.
- The runtime needs the user's own Codex, Claude Code or Gemini CLI subscription.
- Mobile output targets Expo; bare React Native and native code are outside the standard template.
- File attachments, password recovery and test coverage are listed as limitations.
- Database, authentication and storage are not generated; Runner writes code the user wires up.
Questions people ask
Is Runner Builder open source?
Yes. The repository is under GNU AGPL-3.0, an OSI-approved licence. AGPL is a strong copyleft licence: a hosted fork offered to users has to publish its source under the same terms. Runner AI offers paid commercial licences for teams that need a closed-source build.
Does Runner Builder work offline?
Partly. The builder itself runs on the device; the preview is a local Vite or Expo server. The agent backend (Codex CLI, Claude Code or Gemini CLI) calls the matching cloud service for every reply, so an internet connection is required for model turns. A user who switches the agent to a local model (through the Codex CLI's local-model support) can reduce the network dependency.
Can Runner Builder be used commercially?
Yes for internal use. A team can run Runner Builder on its own machines for free under AGPL-3.0. Commercial hosting (selling Runner-as-a-service to third parties) falls under AGPL's hosting clause and needs the source published. A team that wants a closed-source commercial fork or a hosted commercial product should ask Runner AI about a commercial licence.
How does Runner Builder compare with Lovable?
Lovable is a hosted product with a chat UI, automatic deployment and a central agent. Runner Builder is local-first, writes files to the user's own disk, and uses the user's own Codex, Claude Code or Gemini CLI subscription. The trade is: Lovable's hosted ease and instant deploy against Runner's privacy, zero extra model fee and Git-backed history on the laptop. The open-source alternatives to Lovable page sets it beside Onlook, Dyad, Chef and others.
Can a Runner Builder app go to the App Store?
The README names "ship to the App Store and Google Play" as a mobile feature. The flow is Expo's own path: expo build or EAS build, a developer account at Apple or Google, and the standard store review. Runner Builder does not bypass those; it produces an Expo project that the user submits through Expo's tooling.
Sources
- Runner Builder README and LICENSE: github.com/therunnerai/runner-local-ai-app-builder, read 2026-11-09.
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Added November 9, 2026. Every claim above comes from the project's README, LICENSE or model card, read on November 9, 2026, or from the GitHub API on the date shown in the panel. Found an error? Write to reveneau@licheo.com and it is fixed in the next weekly pass. Repository: github.com/therunnerai/runner-local-ai-app-builder.
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