---
title: 'Sel-Sync API'
url: 'https://code-evolve.com/resources/selsync-api'
markdown: 'https://code-evolve.com/resources/selsync-api.md'
date: '2026-09-25'
description: 'Sel-Sync API All information on this page is subject to frequent changes. The Sel-Sync API provides the means for creating various Sel-Sync core entities, each having their own API. Language Support Sel-Sync API is currently only implemented for Typescript. Dependencies Libraries code-extend The S…'
---

# Sel-Sync API

*All information on this page is subject to frequent changes.*

The Sel-Sync API provides the means for creating various Sel-Sync core entities, each having their own API.

## Language Support

Sel-Sync API is currently only implemented for Typescript.

## Dependencies

### Libraries

#### code-extend

The Sel-Sync API makes use of the code-extend library. See [Code-Extend](https://code-evolve.com/resources/code-extend) for details.

#### data def

We use the Data Def framework to configure how versions interact with state. See [Data Def](https://code-evolve.com/resources/data-def) for details.

#### tagspace

#### yjs

### Utilities

- clone
- deepEqual
- uuid

## Responsibilities

- Create runtimes
- Create version managers
- Create sync group managers
- Create sync prop managers
- Create sync props

## Examples

```js
const runtime = useSelSyncApi().createRuntime()
const syncGroupManager = useSelSyncApi().createSyncGroupManager()
const syncPropManager = useSelSyncApi().createSyncPropManager()
const versionManager = useSelSyncApi().createVersionManager()
const syncProp = useSelSyncApi().createSyncProp()
```

# Runtime API

A runtime coordinates versions, sync groups, instances, and sync props on a host.

## Responsibilities

- Manage service state
- Manage sync prop instances

## Hooks

- stateWillChange
- stateChanged
- instanceCreated
- instanceDestroyed

## Methods

# Version API

Sel-Sync versions provide alternative values for stateful sync props.

## Responsibilities

### Entity

- Filter versions
- Create versions
- Delete versions
- Clone versions
- Get metadata
- Set metadata

### State

- Load version state
- Save version state
- Validate version state
- Merge version states
- Compare version states

## Hooks

### Version Manager

- versionCreated
- versionDeleted
- versionModified
- versionStateModified

## Methods

# Instance API

## Responsibilities

- Map versions
- Maintain effective version
- Version resolution
- State observation
- Installation lifecycle
- Local value access

## Hooks

### Lifecycle

- init
- install
- start
- stop
- uninstall

### Version Register

- versionMapped
- effectiveVersionChanged

### State

- localValueChanged
- remoteValueChanged

## Methods

# Sync Prop API

## Persistence Models

### None

The property is not persisted. This model is used for action type sync props, such as HostClick

### Group

A single property state is shared between all hosts. This model is used for sync props such as AreasScrollPosition

### Host

A state is stored per-host. This model is used for sync props such as HostSelection

### Instance

A state is stored per-instance. This model is used for sync props such as *tbd*

## Responsibilities

- Sync Prop ID
- Metadata
- Data Block Definition
- Publishing
- Enumerating

## Hooks

## Methods

# Sync Group API

Sync groups associate entities.

## Entity Types

- sync prop
- user
- constraint
- resource
- configuration

## Responsibilities

- Manage sync group lifecycle
- Enumerate sync groups
- Manage entities 
    ## Hooks
- start (deprecated)
- stop (deprecated)
- stateWillChange
- stateChanged
- entityAdded
- entityRemoved
- entityModified (new)

## Methods

---

## Navigation

- Previous: [Sel-Sync](https://code-evolve.com/resources/selsync.md)
- Next: [Sel-Sync Aspects](https://code-evolve.com/resources/selsync-aspects.md)