Molecule.dev

is an AI-first composable package ecosystem.

Open source. Real architecture. Ship in minutes. Built to scale.

Built like the best teams

Code is cheap.
Scaling is not.

Code generation is now the easy part. The last 10%, the part that separates a toy prototype from a business that grows on hard data, is where Molecule lives.

  • No lock-in
  • Tested
  • CI/CD
  • Migrations
  • Monitoring
  • Logging
  • Analytics
  • Security
Start building
synthase

An AI travel agent that books flights by voice, rebooks when they’re delayed, and splits the bill.

from the catalog

  • Picked 8 packages from the catalog
  • Wired them like hand-written code
  • Type-checked, linted and tested
  • Live preview ready

Real architecture

A step above vibe coding.

Not a throwaway prototype. Real, decoupled architecture that teams of seasoned professionals can own, audit, and scale. Every provider sits behind a swappable bond, so changing the database is one import, not a rewrite.

The same pattern for every category

Frameworks and platforms swap the same way.

core interface@molecule/api-databasefindMany · create · update …

bond (provider)

@molecule/api-database-postgresqlPostgreSQL@molecule/api-database-mysqlMySQL@molecule/api-database-sqliteSQLite@molecule/api-database-d1Cloudflare D1
api/src/bonds.ts
// the one wiring fileimport { pool, store } from '@molecule/api-database-postgresql'mysql'sqlite'd1'setPool(pool); setStore(store)

Open by design

Open source, no lock-in.

Open source

Apache-2.0. Browse and self-host everything.

Always expanding

New providers and integrations land constantly, from us and the community.

Deploy with us

Optional. Pay only for the metered AI and infrastructure you use.

Everything a real app needs.

Every app needs the same integrations (payments, uploads, notifications, etc.), and most AI tools regenerate them from scratch every time. Molecule already does this for you, battle-tested, so your tokens go toward what really matters.

Built for AI, from the ground up.

Complete, tested packages you can drop in, documented so any AI agent can understand and wire them together: Synthase in the molecule.dev IDE, the mlcl CLI, or your own agent over MCP.

Self-improving

Apps that keep getting better.

Built-in analytics, error tracking and feedback let the AI keep improving the app from real use. Every release a little better, measured rather than guessed.

from the running app

the AI, in your workspaceShortens onboarding to one step · fixes the export · adds CSVType-checked, tested and deployed. You approve, or let it run.

next release: sign-ups up, export errors gone

Swap the analytics provider; the instrumentation stays.

Frequently asked questions

What is Molecule.dev?

An open-source catalog of composable packages, and an AI agent, Synthase, that assembles, runs and deploys full-stack apps from it. Use it from the molecule.dev IDE, from the command line with mlcl, or from any coding agent through the MCP server.

How does it work?

Describe what you want in your own words. Synthase picks packages from the catalog, reads their generated docs and wires them like hand-written code, runs the result in a live preview, and deploys it when you say so. Every app ships with analytics, error tracking and user feedback built in, and the agent keeps improving it from what they report.

Can I use it without the IDE?

Yes. npx mlcl create scaffolds a project from the catalog on your own machine, npx mlcl mcp install gives any coding agent the same packages, docs and scaffolder, and every @molecule package installs like any other dependency.

What stack does it build with?

Any modern web framework, native mobile from the same code, and an API on any host or database. Every provider sits behind a swappable bond, so nothing is tied to one stack, and packages are added as stacks change.

How is it different from other AI coding tools?

It composes tested, maintained packages instead of generating the same code again for every project. That is faster, uses far fewer tokens, and leaves you with real, decoupled architecture a team can own, audit and scale, not a throwaway prototype.

Can I use it with an app I already have?

Two ways. Connect your repo, and Synthase adds the features and integrations you ask for directly to your codebase. Or install the open-source @molecule packages into your project and wire them in with the bond pattern, like any dependency.

How do I find the right package or template?

Search the catalog by name, by category (category:auth), by what a package exports, or in plain words like “user feedback”. Templates work the same way. Press / on either page to search, and every search is a link you can share.

Is there any lock-in?

None. You own the code, real and readable, built on open-source packages (Apache-2.0). Swap any provider, export it with its database and keys, self-host anything.

What does it cost?

Free to self-host. Build and deploy on molecule.dev and pay only for the AI and infrastructure you use.

Start

Three ways in.

The same open-source packages and the same agent, from wherever you already work.

  • molecule.dev

    Describe it in the IDE

    Start building

    Synthase builds, tests and deploys it in a workspace you can share.

  • Command line

    Scaffold it with mlcl

    The catalog wired into a plain project, in your own editor.

  • Any coding agent

    Give your agent the catalog

    The MCP server hands any agent the packages, their docs and the scaffolder.

Plain code you own. Export it, with its database and keys, at any time.Apache-2.0 · no lock-in · any editor, agent or CI.

Get startedBrowse on GitHub