PLEASE READ: As farmOS.js version 2.0.0 approaches its general release, be aware that there have recently been, and may continue to be, breaking changes in the beta.x releases. Most notably, the 2.0.0-beta.12 contains several breaking changes. It is advised that if you use any of these beta releases you be careful to pin your dependencies to an exact version number in your package.json file's dependencies.


farmOS.js is a JavaScript library for working with farmOS data structures and interacting with farmOS servers.

The need for farmOS.js arose out of development of the farmOS Field Kit app, which required the ability to work offline and to work with farmOS servers in varying configurations that could only be determined at runtime. To solve this, farmOS.js retrieves and stores JSON Schema documents from the servers it connects to. It then uses these schemata to generate farmOS data structures according to each server's particular configuration to ensure they will be validated by that server. To resolve the conflicts that inevitably arise from storing and modifying concurrent data while offline, farmOS.js implements a "last-write-wins" merging strategy, so synchronization can be handled more fluidly and intuitively.

Altogether, this has shaped farmOS.js into a system with robust support for both modularity and concurrency, opening up the potential for the development of a wider array of interoperable applications.

Requirements & browser support

farmOS.js supports the farmOS 2.x Data Model, compatible with farmOS 2.x servers. Previous versions will no longer be supported.

farmOS.js can run in Node.js (versions 13.2.0 or higher), and in most modern browsers. IE 11 is not supported.

Quick start

Learn farmOS.js by example.

1. Install farmOS.js via npm

$ npm install farmos

2. Create a farm instance

import farmOS from 'farmos';

const options = {
  remote: {
    host: '',
    clientId: 'farm',
const farm = farmOS(options);

3. Connect to a remote farmOS server

const username = 'Farmer Sam';
const password = '123_you_cant_guess_me';
farm.remote.authorize(username, password);

4. Retrieve JSON schema for farmOS record types from the server

  .then((schemata) => {
    localStorage.setItem('farm_schemata', JSON.stringify(schemata));

5. CRUD operations with a farmOS log

const initProps = { type: 'log--activity', name: 'did some stuff' };
const activity = farm.log.create(initProps);
const { id } = activity; // `id` is a v4 UUID
  .then(() => farm.log.fetch({ filter: { type: 'log--activity', id } }))
  .then(({ data: [remoteActivity] }) => {
    const updateProps = { name: 'did some more stuff' };
    const updatedActivity = farm.log.update(activity, updateProps);
    // Merge operations use a "Last-Write-Wins" (LWW) concurrency strategy.
    const mergedActivity = farm.log.merge(updatedActivity, remoteActivity);
    return farm.log.delete('activity', id);

Next steps

Now that you know the basics, dive deeper into following topics:

Or, go straight to the API reference.