📄 tanstack/db/latest/docs/collections/trailbase-collection

TrailBase collections provide seamless integration between TanStack DB and TrailBase , enabling real-time data synchronization with TrailBase's self-hosted application backend.

Overview
--------

TrailBase is an easy-to-self-host, single-executable application backend with built-in SQLite, a V8 JS runtime, auth, admin UIs and sync functionality.

The @tanstack/trailbase-db-collection package allows you to create collections that:

Automatically sync data from TrailBase Record APIs
Support real-time subscriptions when enable_subscriptions is enabled
Handle optimistic updates with automatic rollback on errors
Provide parse/serialize functions for data transformation

Installation
------------

bash

npm install @tanstack/trailbase-db-collection @tanstack/react-db trailbase


npm install @tanstack/trailbase-db-collection @tanstack/react-db trailbase

Basic Usage
-----------

typescript

import { createCollection } from '@tanstack/react-db'
import { trailBaseCollectionOptions } from '@tanstack/trailbase-db-collection'
import { initClient } from 'trailbase'

const trailBaseClient = initClient(`https://your-trailbase-instance.com`)

const todosCollection = createCollection(
  trailBaseCollectionOptions({
    id: 'todos',
    recordApi: trailBaseClient.records('todos'),
    getKey: (item) => item.id,
  })
)


import { createCollection } from '@tanstack/react-db'
import { trailBaseCollectionOptions } from '@tanstack/trailbase-db-collection'
import { initClient } from 'trailbase'

const trailBaseClient = initClient(`https://your-trailbase-instance.com`)

const todosCollection = createCollection(
  trailBaseCollectionOptions({
    id: 'todos',
    recordApi: trailBaseClient.records('todos'),
    getKey: (item) => item.id,
  })
)

Configuration Options
---------------------

The trailBaseCollectionOptions function accepts the following options:

### Required Options

id: Unique identifier for the collection
recordApi: TrailBase Record API instance created via trailBaseClient.records()
getKey: Function to extract the unique key from an item

### Optional Options

schema: Standard Schema compatible schema (e.g., Zod, Effect) for client-side validation
parse: Object mapping field names to parsing functions that transform data coming from TrailBase
serialize: Object mapping field names to serialization functions that transform data going to TrailBase
onInsert: Handler function called when items are inserted
onUpdate: Handler function called when items are updated
onDelete: Handler function called when items are deleted

Data Transformation
-------------------

TrailBase uses different data formats for storage (e.g., Unix timestamps). Use parse and serialize to handle these transformations:

typescript

type SelectTodo = {
  id: string
  text: string
  created_at: number // Unix timestamp from TrailBase
  completed: boolean
}

type Todo = {
  id: string
  text: string
  created_at: Date // JavaScript Date for app usage
  completed: boolean
}

const todosCollection = createCollection<SelectTodo, Todo>(
  trailBaseCollectionOptions({
    id: 'todos',
    recordApi: trailBaseClient.records('todos'),
    getKey: (item) => item.id,
    schema: todoSchema,
    // Transform TrailBase data to application format
    parse: {
      created_at: (ts) => new Date(ts * 1000),
    },
    // Transform application data to TrailBase format
    serialize: {
      created_at: (date) => Math.floor(date.valueOf() / 1000),
    },
  })
)


type SelectTodo = {
  id: string
  text: string
  created_at: number // Unix timestamp from TrailBase
  completed: boolean
}

type Todo = {
  id: string
  text: string
  created_at: Date // JavaScript Date for app usage
  completed: boolean
}

const todosCollection = createCollection<SelectTodo, Todo>(
  trailBaseCollectionOptions({
    id: 'todos',
    recordApi: trailBaseClient.records('todos'),
    getKey: (item) => item.id,
    schema: todoSchema,
    // Transform TrailBase data to application format
    parse: {
      created_at: (ts) => new Date(ts * 1000),
    },
    // Transform application data to TrailBase format
    serialize: {
      created_at: (date) => Math.floor(date.valueOf() / 1000),
    },
  })
)

Real-time Subscriptions
-----------------------

TrailBase supports real-time subscriptions when enabled on the server. The collection automatically subscribes to changes and updates in real-time:

typescript

const todosCollection = createCollection(
  trailBaseCollectionOptions({
    id: 'todos',
    recordApi: trailBaseClient.records('todos'),
    getKey: (item) => item.id,
    // Real-time updates work automatically when
    // enable_subscriptions is set in TrailBase config
  })
)

// Changes from other clients will automatically update
// the collection in real-time


const todosCollection = createCollection(
  trailBaseCollectionOptions({
    id: 'todos',
    recordApi: trailBaseClient.records('todos'),
    getKey: (item) => item.id,
    // Real-time updates work automatically when
    // enable_subscriptions is set in TrailBase config
  })
)

// Changes from other clients will automatically update
// the collection in real-time

Mutation Handlers
-----------------

Handle inserts, updates, and deletes by providing mutation handlers:

typescript

const todosCollection = createCollection(
  trailBaseCollectionOptions({
    id: 'todos',
    recordApi: trailBaseClient.records('todos'),
    getKey: (item) => item.id,
    onInsert: async ({ transaction }) => {
      const newTodo = transaction.mutations[0].modified
      // TrailBase handles the persistence automatically
      // Add custom logic here if needed
    },
    onUpdate: async ({ transaction }) => {
      const { original, modified } = transaction.mutations[0]
      // TrailBase handles the persistence automatically
      // Add custom logic here if needed
    },
    onDelete: async ({ transaction }) => {
      const deletedTodo = transaction.mutations[0].original
      // TrailBase handles the persistence automatically
      // Add custom logic here if needed
    },
  })
)


const todosCollection = createCollection(
  trailBaseCollectionOptions({
    id: 'todos',
    recordApi: trailBaseClient.records('todos'),
    getKey: (item) => item.id,
    onInsert: async ({ transaction }) => {
      const newTodo = transaction.mutations[0].modified
      // TrailBase handles the persistence automatically
      // Add custom logic here if needed
    },
    onUpdate: async ({ transaction }) => {
      const { original, modified } = transaction.mutations[0]
      // TrailBase handles the persistence automatically
      // Add custom logic here if needed
    },
    onDelete: async ({ transaction }) => {
      const deletedTodo = transaction.mutations[0].original
      // TrailBase handles the persistence automatically
      // Add custom logic here if needed
    },
  })
)

Complete Example
----------------

typescript

import { createCollection } from '@tanstack/react-db'
import { trailBaseCollectionOptions } from '@tanstack/trailbase-db-collection'
import { initClient } from 'trailbase'
import { z } from 'zod'

const trailBaseClient = initClient(`https://your-trailbase-instance.com`)

// Define schema
const todoSchema = z.object({
  id: z.string(),
  text: z.string(),
  completed: z.boolean(),
  created_at: z.date(),
})

type SelectTodo = {
  id: string
  text: string
  completed: boolean
  created_at: number
}

type Todo = z.infer<typeof todoSchema>

// Create collection
export const todosCollection = createCollection<SelectTodo, Todo>(
  trailBaseCollectionOptions({
    id: 'todos',
    recordApi: trailBaseClient.records('todos'),
    getKey: (item) => item.id,
    schema: todoSchema,
    parse: {
      created_at: (ts) => new Date(ts * 1000),
    },
    serialize: {
      created_at: (date) => Math.floor(date.valueOf() / 1000),
    },
    onInsert: async ({ transaction }) => {
      const newTodo = transaction.mutations[0].modified
      console.log('Todo created:', newTodo)
    },
  })
)

// Use in component
function TodoList() {
  const { data: todos } = useLiveQuery((q) =>
    q.from({ todo: todosCollection })
      .where(({ todo }) => !todo.completed)
      .orderBy(({ todo }) => todo.created_at, 'desc')
  )

  const addTodo = (text: string) => {
    todosCollection.insert({
      id: crypto.randomUUID(),
      text,
      completed: false,
      created_at: new Date(),
    })
  }

  return (
    <div>
      {todos.map((todo) => (
        <div key={todo.id}>{todo.text}</div>
      ))}
    </div>
  )
}


import { createCollection } from '@tanstack/react-db'
import { trailBaseCollectionOptions } from '@tanstack/trailbase-db-collection'
import { initClient } from 'trailbase'
import { z } from 'zod'

const trailBaseClient = initClient(`https://your-trailbase-instance.com`)

// Define schema
const todoSchema = z.object({
  id: z.string(),
  text: z.string(),
  completed: z.boolean(),
  created_at: z.date(),
})

type SelectTodo = {
  id: string
  text: string
  completed: boolean
  created_at: number
}

type Todo = z.infer<typeof todoSchema>

// Create collection
export const todosCollection = createCollection<SelectTodo, Todo>(
  trailBaseCollectionOptions({
    id: 'todos',
    recordApi: trailBaseClient.records('todos'),
    getKey: (item) => item.id,
    schema: todoSchema,
    parse: {
      created_at: (ts) => new Date(ts * 1000),
    },
    serialize: {
      created_at: (date) => Math.floor(date.valueOf() / 1000),
    },
    onInsert: async ({ transaction }) => {
      const newTodo = transaction.mutations[0].modified
      console.log('Todo created:', newTodo)
    },
  })
)

// Use in component
function TodoList() {
  const { data: todos } = useLiveQuery((q) =>
    q.from({ todo: todosCollection })
      .where(({ todo }) => !todo.completed)
      .orderBy(({ todo }) => todo.created_at, 'desc')
  )

  const addTodo = (text: string) => {
    todosCollection.insert({
      id: crypto.randomUUID(),
      text,
      completed: false,
      created_at: new Date(),
    })
  }

  return (
    <div>
      {todos.map((todo) => (
        <div key={todo.id}>{todo.text}</div>
      ))}
    </div>
  )
}

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----------

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