molecule
An open-source ecosystem of hundreds of small, composable full-stack packages, plus a CLI, an MCP server and a website tool, designed so an AI agent can assemble a working application from them and a developer can export plain, ownable TypeScript.
molecule packages cover more than 80 categories such as database, auth, payments, email, AI and analytics, and every provider or frontend framework, including React, Vue, Svelte, Solid, Angular and React Native, sits behind a swappable interface the project calls a bond, so changing a provider means changing the wiring rather than rewriting the app. A user describes the app they want, and the website tool, called Synthase, or the mlcl command-line tool, picks packages and wires them together behind a live sandbox preview, starting from a library of working, tested templates rather than a blank prompt.
Generated code is type-checked, linted and tested before it reaches the developer, with errors fed back to the agent until the checks pass, and unit, integration and end-to-end tests ship with the generated project; the output can be deployed through the project's own hosting or exported as plain TypeScript, a database dump and environment files that a developer owns outright. An agent working with molecule is expected to read a package's generated README, call its core interface rather than a vendor SDK directly, and wire providers in a bonds.ts file.
Built-in features include OAuth, payments, migrations, internationalization, analytics, logging, error tracking, realtime, uploads, push notifications, search, feature flags and CI/CD. It is written in TypeScript and released under packages licensed under Apache-2.0.