lowdefy: Open Source Automation

What is lowdefy?

Lowdefy is an Apache-2.0 JavaScript framework that builds full-stack web apps — internal tools, admin panels, dashboards, and CRUD apps — from schema-validated YAML config instead of hand-written React, for teams that want AI to generate the app while humans review and maintain it.

What it is

Lowdefy is a config-first web stack in which an application is described entirely in a lowdefy.yaml file: pages, blocks, events, actions, and data requests are declared as YAML rather than written as JavaScript. The runtime is built on Hono and Vite with Auth.js, deploys anywhere Node.js runs, and interprets the config at run time. UI is composed from 70+ React components called Blocks, logic from 50+ operators such as _if, _get, _js, and _state, and data access from Connections and Requests to external systems. Extensibility is handled through npm packages.

The concrete problem is the maintenance cost of AI-generated code. The README states that AI writes code fast, but LLMs generate thousands of lines that are hard to review, inconsistent across sessions, and full of hidden vulnerabilities, and that fixing each generated codebase individually does not scale. Lowdefy replaces those sprawling React components with concise config — the project contrasts roughly 50 lines of config against 500 lines of code. Because config is schema-validated and interpreted rather than executed, there are no arbitrary code paths and no code injection vector, and a single framework update benefits every app built on it instead of requiring per-app fixes.

Key capabilities

Application definition in lowdefy.yaml, covering pages, blocks, events, and onClick action handlers.
70+ UI Blocks spanning forms, tables, charts, and markdown, with custom blocks added through npm plugins.
50+ logic operators including _if, _get, _js, and _state for dynamic interfaces and state management without writing code.
10+ data connectors: MongoDB, PostgreSQL, MySQL, REST APIs, Google Sheets, S3, Elasticsearch, and Stripe.
Auth and RBAC built into the runtime, with 75+ auth providers, public and private pages, and role-based access control.
Plugin extensibility across Blocks, Connections, Operators, Actions, Auth Providers, and Adapters, with tree-shaking that bundles only what is used.
Runtime built on Hono, Vite, and Auth.js, with every property validated against a schema.

Who uses it and how

Teams building internal tools and admin panels over data that already lives in MongoDB, PostgreSQL, MySQL, or Elasticsearch.
Dashboard work that combines charts, tables, and markdown over one or more connected sources, including Google Sheets and S3.
AI-assisted development workflows where a model generates config and a human reviews the diff, which is practical because the artifact is short and schema-validated.
Self-hosters running the app on their own Node.js infrastructure; Resonancy offers a build-it-for-you service.
Organisations that need role-based access control across a mix of public pages and private pages with any of 75+ auth providers.

Getting started

Run npx lowdefy@latest init && npx lowdefy@latest dev. This creates a lowdefy.yaml in the current directory and launches a local development server at http://localhost:3000, where edits to the config are reflected in the running app.

How it compares

No similar tools are named in the provided facts, so Lowdefy stands alone in this registry. It carries an Apache-2.0 licence, is self-hostable, and keeps application logic in config that the team owns rather than in generated source files.

When to use it — and when not to

A self-hoster operates the Node.js runtime and, separately, every backend the app connects to — MongoDB, PostgreSQL, MySQL, or others are not supplied by Lowdefy. Teams that need unrestricted hand-written React or arbitrary code execution should not choose it, because the interpreted-config model is the deliberate trade-off that removes code injection risk. Plugin authoring also means publishing npm packages and, for the example plugins, working in a pnpm monorepo, so the extension path is a developer task rather than a config edit.

project readme (upstream, from github) — read inline

Lowdefy

Lowdefy - The Config-First Web Stack for AI and Humans

Build apps that AI can generate, humans can review, and teams can maintain. Config that works between code and natural language.

Why config-first matters in the age of AI

AI writes code fast, but the maintenance doesn't scale. LLMs generate thousands of lines that are hard to review, inconsistent across sessions, and full of hidden vulnerabilities. Lowdefy solves this:

50 lines of config vs 500 lines of code — AI generates concise, reviewable config instead of sprawling React components.
Schema-validated, no arbitrary code paths — Every property validated against a schema. No arbitrary code paths.
One framework update upgrades all your apps — Config is stable. Lowdefy updates benefits all apps. No fixing each AI-generated codebase individually.
Config is interpreted, not executed — No code injection possible. Auth, permissions, and data validation built into the runtime.

Full-stack, production-ready

Built on Hono and Vite with Auth.js — Deploy anywhere Node.js runs.
70+ UI components — Forms, tables, charts, markdown, and more out of the box.
50+ logic operators — _if, _get, _js, _state for dynamic UIs without writing code.
10+ data connectors — MongoDB, PostgreSQL, MySQL, REST APIs, Google Sheets, S3, Elasticsearch, Stripe.
Auth & RBAC — 75+ auth providers, public and private pages, role-based access control.

Extend with npm plugins

Blocks, Connections, Operators, Actions, Auth Providers, and Adapters can all be extended with plugins. Declare them in config — Lowdefy handles the rest.

Tree-shaking bundles only what you use. Build custom plugins with npm packages and publish them for the community.

https://docs.lowdefy.com/plugins-introduction
https://github.com/lowdefy/lowdefy-example-plugins (pnpm monorepo setup)
https://github.com/lowdefy/community-plugins

Quick Start

npx lowdefy@latest init && npx lowdefy@latest dev

This creates a lowdefy.yaml in the current directory and launches a local development server at http://localhost:3000. Edit the config to see changes reflected in the app.

How It Works

lowdefy: 4
pages:
  - id: welcome
    type: PageHeaderMenu
    blocks:
      - id: card
        type: Card
        blocks:
          - id: name
            type: TextInput
            properties:
              label: What's your name?
          - id: greeting
            type: Alert
            properties:
              type: success
              message:
                _js: |
                  const n = state('name');
                  return n ? `Hello, ${n}!` : 'Type your name';
          - id: submit
            type: Button
            properties:
              title: Save
            events:
              onClick:
                - id: validate
                  type: Validate

Lowdefy apps are built using:

Blocks — 70+ React UI components, from forms and tables to charts and markdown. Extend with custom blocks via npm plugins.
Operators — 50+ logic functions (_if, _get, _js) for dynamic UIs with simple state management.
Actions — Event handlers triggered by clicks, page loads, and more. Validate, navigate, call APIs, and set state.
Connections & Requests — Connect to MongoDB, PostgreSQL, MySQL, REST APIs, Google Sheets, S3, Elasticsearch, Stripe, and more.

Lowdefy is built and maintained by Resonancy

🚀 Too many apps? https://resonancy.io builds it for you.

Most teams run 10+ business apps that don't talk to each other. https://resonancy.io replaces them with one purpose-built solution on Lowdefy — delivered in days, not months.

Consolidate your stack — Replace disconnected apps with one unified solution.
Streamline workflows — Seamlessly integrated systems that free up your team.
Ship in days — Custom apps built fast with Lowdefy.
Connect everything — Real-time data across your business for reliable insights.

✅ One unified app replacing your SaaS dependency · ✅ Custom solution tailored to your business · ✅ AI, data science & integrations included · ✅ Ongoing support & managed hosting

10+ years building business apps. 50+ internal tools deployed. Built on open source.

https://resonancy.io

Contributing

Platform Development

Run Lowdefy servers locally by adding your config to the app/ folder:

pnpm app:dev — Start the development server.
pnpm app:build — Create a production build.
pnpm app:start — Start the production server.

Use pnpm app:dev -- --path to run a specific app directory (e.g. a test app). See CONTRIBUTING.md for more. See the project package.json scripts for more predefined scripts.

See CONTRIBUTING.md for more.

Changelog

All changes are documented in CHANGELOG.md. Converting from v3? See the v4 migration guide.

Security

If you discover a vulnerability, please follow the guide in SECURITY.md.

Code of Conduct

See CODE_OF_CONDUCT.md.

Frequently asked questions

Is lowdefy free to use?

lowdefy is open source under the Apache-2.0 licence. There is no licence fee and no seat count — you can self-host it or, where the project offers one, pay a vendor for a managed version instead.

What does lowdefy do?