Flutter

Once you've started receiving data from a device into your app, you can start sending this data to Terra's websocket server.

Prerequisite

Before following the steps below, make sure you've followed the guide to stream data from a wearable device to your app

Streaming to Terra's Server

You'll have previously set up a local stream using startRealtimeToApp. To send data to Terra's server instead, use startRealtimeToServer with a streaming token:

import 'package:terra_flutter_rt/terra_flutter_rt.dart';
import 'package:terra_flutter_rt/types.dart';

Future<void> startServerStreaming() async {
  // 1. Get the Terra user ID
  final userId = await TerraFlutterRt.getUserId();
  if (userId == null) return;

  // 2. Get a streaming token from your backend
  final token = await fetchStreamingTokenFromBackend(userId);

  // 3. Start streaming to Terra's server
  await TerraFlutterRt.startRealtimeToServer(
    Connection.ble,
    [DataType.heartRate, DataType.steps],
    token,
  );
}

Flutter has separate functions for local vs server streaming:

• startRealtimeToApp — streams to a local callback only (no server)

• startRealtimeToServer — streams to Terra's websocket server only (no local callback)

To receive data both locally and on your server, call startRealtimeToApp for the local callback and have your backend consume from the Terra websocket.

Your backend should generate the streaming token by calling:

Stream - Generate user token

post

Endpoint for generation of a token for a user (producer) connection

Authorizations

apiKeyAuth & devIdAuth

x-api-keystringRequired

dev-idstringRequired

Query parameters

idstringOptional

The ID of the user to generate a token for

Header parameters

dev-idstringRequired

your developer ID

x-api-keystringRequired

your API key

Responses

200

Successful response

application/json

tokenstringOptionalExample: OTYwNWFi5ZWQMTAxMjg0Y2Qw.gzrPzZcS3Gy8QDOxbiPRwu30PTB3VxW0eE

403

Forbidden

text/plain

post

/auth/user

HTTPcURLJavaScriptPython

POST /auth/user HTTP/1.1
Host: ws.tryterra.co
x-api-key: text
dev-id: text
Accept: */*

{
  "token": "OTYwNWFi5ZWQMTAxMjg0Y2Qw.gzrPzZcS3Gy8QDOxbiPRwu30PTB3VxW0eE"
}