Choose an SDK

Most applications use two SDKs:

A client SDK creates a stable visitorId.
The Node SDK sends the conversation to Era and returns a context block.

SDK comparison

Your code runs in	Package	Use it for	Key type
Browser	`@seasonlabs/era-web`	Create a visitor ID and verify email or phone	Publishable
Flutter app	`era_flutter`	Create a visitor ID and verify email or phone	Publishable
Trusted backend	`@seasonlabs/era-node`	Get the context block for a conversation	Secret

Never put a Node SDK API key in browser or mobile code.

Browser application

Use the Web SDK in the browser and the Node SDK on your backend.

Browser

const visitorId = await eraWeb.init();

await fetch("/api/chat", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({ messages, visitorId }),
});

Trusted backend

const block = await era.turnContext(messages, {
  visitorId,
  sessionId,
});

Flutter application

Use era_flutter in the app and the Node SDK on your backend.

Flutter

final visitorId = await era.init();

Send visitorId with the chat request. Your backend uses it in the same turnContext() call shown above.

Backend-only application

The Node SDK still needs a stable visitorId. Create and store one for each user or visitor, then pass it on every turn.

Signed-in users

When your backend knows the signed-in user, add your own stable user ID:

const block = await era.turnContext(messages, {
  visitorId,
  partnerEndUserId: authenticatedUser.id,
  sessionId,
});

partnerEndUserId adds trusted account identity, but it does not replace visitorId. Only send email or phone assertions that your backend has already verified.

Node SDK quickstart

Request your first context block.

Web SDK quickstart

Create a browser visitor.

Flutter SDK quickstart

Create a mobile visitor.

Overview

API reference

Use cases

SDK comparison

Browser application

Flutter application

Backend-only application

Signed-in users

Node SDK quickstart

Web SDK quickstart

Flutter SDK quickstart

​SDK comparison

​Browser application

​Flutter application

​Backend-only application

​Signed-in users

Node SDK quickstart

Web SDK quickstart

Flutter SDK quickstart

SDK comparison

Browser application

Flutter application

Backend-only application

Signed-in users