Landbot.Core

The core class — constructor, properties, and methods for sending and reading messages.

The Landbot.Core class is the entry point to the SDK. Construct it with a bot config object (see Install for how to fetch one), then use the instance to send and read messages.

Constructor

Landbot.Core

Landbot.Core(config)

Parameters:

config: Object

Create a Landbot.Core instance.

Properties

config

Type: Object

The config object the instance was created with.

events

Type: Object

Event emitter instance. See Events.

pipelines

Type: Object

Pipelines instance. See Pipelines.

Methods

init

init()

Returns:

Promise

Core initialization. Returns a Promise that resolves with data.messages — the conversation history for this bot session (welcome bundle + any previous conversation if persistent storage is enabled).

core.init().then(function (data) {
  console.log(data.messages);
});

Note data.messages can be empty. On bots without persistent storage, or on fresh sessions where the welcome arrives via pipelines rather than as a history bundle, data.messages resolves to []. Don't rely on init() alone to seed your UI — subscribe to $readableSequence (or another pipeline) before calling init() so the welcome messages are caught by your subscription regardless of whether the Promise carries them.

destroy

destroy()

Destroy the Landbot.Core instance and all its listeners. Call this when the host UI is being torn down to free resources.

Warning Don't reuse a destroyed instance. Post-destroy calls don't throw — sendMessage silently resolves and pipelines.*.subscribe accepts the call without delivering any messages. Looks like it worked, but nothing happens. To start a new conversation, construct a fresh Core with the same config.

A fresh Core does not continue the previous conversation — it re-runs the welcome flow with a new message key. Sessions are not sticky across instances.

sendMessage

sendMessage(message)

Parameters:

message: Object

Returns:

Promise

Sends a message to the bot from the client side. See Messages for the supported message structures.

core.sendMessage({ message: 'Hey bro!' });

getLastMessages

getLastMessages(amount)

Parameters:

amount: Number

Returns:

Promise

Return the last amount messages stored in the database.

core
  .getLastMessages(25)
  .then(function (data) {
    console.log(data);
  });

Warning Requires persistent storage on the bot. If the bot was configured with storage disabled (the storage_off flag in its config), both getLastMessages and getMoreMessages throw:

TypeError: Cannot read properties of null (reading '_query')

> 
> The error is the SDK reaching for a Firestore reference that was never initialised. Before relying on these methods, verify the fetched config has `storage_off: false` — or wrap calls in `try { … } catch { … }` and degrade gracefully when storage isn't available.

### getMoreMessages

**getMoreMessages(amount)**

Parameters:

- amount: *Number*

Returns:

- *Promise*

Return `amount` messages stored in the database. An internal increasing counter lets this function be called repeatedly to retrieve older and older messages — a typical infinite-scroll back-pagination pattern.

```javascript
core
  .getMoreMessages(25)
  .then(function (data) {
    console.log(data);
  });

Same persistent-storage requirement applies as getLastMessages — see that warning.

Install

Messages