Build apps that work
with every tool you use
Describe an app and the coding agent already on your computer writes it, with a live preview as it works. Every app is connected to 1,071 apps and 140,544 actions through One, and goes live in one click. It's a Forkable business, so you fork it and run your own.
Runs on Claude Code or Codex. No credits, your agent's own plan pays for the work.
Claude CodePublishWhat should we build?
A new project, ready in seconds
Every app comes
connected
Building an app that touches Gmail or Stripe used to mean an OAuth app per tool, tokens to store and refresh, and a login to build. Here every app starts with 1,071 apps and 140,544 actions one prompt away.
1,071 apps · 140,544 actions
The agent reads the catalog
Your coding agent looks actions up in One's catalog as it builds, so the calls it writes use real action ids and real parameters, not guesses.
A typed client per action
Every action the app uses gets a typed wrapper generated from its schema. A wrong field is a type error before it is a failed call.
Sign in with One, prewired
Every app ships with the sign-in button and its two routes. People sign in and connect their own Gmail, Slack or Stripe. No provider keys in the code.
Asks for what the code calls
The app's access list is read from the actions in its code, so the consent screen asks for exactly what the app uses and nothing more.
server/inbox.tswritten by the agentimport { one, requireUser } from "./one";
import { gmail } from "./one/actions.gen";
inbox.get("/threads", async (c) => {
await requireUser(c);
const r = await one(c).run(gmail.listAndViewEmailThreads, {
body: { numberOfThreads: 10, label: "INBOX" },
});
if (!r.ok) return c.json(r, r.status);
return c.json({ threads: r.data.threads });
});Your agent, on your machine
Chat on the left, the running app on the right. The agent writes real code in a real repo, and you watch every step land in the preview.
Your agent does the work
Claude Code or Codex, the one you already have and are signed in to. Builder finds it and drives it. No credits, its own plan pays.
Point at what to change
Select an element in the preview and ask, edit text in place, or leave a comment. The agent gets the file and line.
Errors fix themselves
Type errors, build errors and crashes in the preview go back to the agent on their own, until the app runs clean.
Plan before it builds
Plan mode reads and proposes, nothing is edited. Build the plan when it reads right.
Every turn is a version
Each turn ends in a checkpoint with a screenshot and the diff. Preview any version, or restore it in one step.
A real git repo, yours
Projects live on your machine as plain React, Hono and Drizzle in a git repo. Open them in your own editor any time.
Claude CodeSigned in · defaultCodexSigned in- Daily Stripe digest to Slack8aee5f7 · +286 −2Live
- Show totals per customer41c09d2 · +58 −124 min
- Fixing 1 errorc7b2cbc · +3 −16 min
- Revenue page with filters2b7ef6a · +190 −09 min
One click to live
Press Publish. The version you are looking at gets checked, built and deployed, and you get a URL to send.
Checks
- Typecheck
- Build
- No secrets in the code
- Manifest matches the code
- pnpm audit
Where to
VercelGitHub- 1
Checked before it ships
Typecheck, build, a scan for secrets in the code and the bundle, the access list against the code, and pnpm audit. A failing check blocks the publish and hands the findings to the agent.
- 2
Vercel or GitHub
Deploy to Vercel, or export the repo to GitHub, private unless you say otherwise. Both run on your own One account.
- 3
Live with sign-in on
The published app keeps Sign in with One, so the people who use it connect their own tools and can revoke them any time.
Questions people ask
What do I need to run it?
macOS or Linux, Node 22, and Claude Code or Codex installed and signed in. Fork it, run it, and type what you want on Home. The first project is ready in about a minute; after that, a few seconds.
Who pays for the AI?
You do, directly, through the coding agent you already use. There are no credits and no markup. Builder drives your Claude Code or Codex, and its plan covers the turns.
How does an app connect to Gmail, Slack or Stripe?
Through One. The agent finds the action in One's catalog and writes a typed call to it. The people who use your app sign in with One and connect their own accounts, so the app never holds a provider key.
What does one-click publish actually do?
It checks the version you are on (typecheck, build, secrets, access list, audit), then deploys it to Vercel or exports it to a GitHub repo, on your own One account.
Is the code mine?
Yes. Every project is a plain git repo on your machine: React, Hono and Drizzle. Builder itself is open source.
Fork it and
make it yours
One line gives you the whole builder and its code, running on your computer. Watch the keyless demo first, then describe your first app.
- Runs on your Claude Code or Codex
- Every app connected through One
- Sign in with One in every app
- One-click publish to Vercel or GitHub
Secured by One. Each user connects their own accounts and can revoke them any time.