SignalR Streaming

Beacon Tower provides real-time push notifications over SignalR, enabling dashboards and integrations to receive live asset telemetry and alarm updates without polling.

Overview

SignalR streaming is the recommended approach for applications that need low-latency, real-time asset data — operational dashboards, live monitoring UIs, and event-driven integrations.

Connection Flow

Client Application
      ↓
POST /push/negotiate (obtain connection URL + token)
      ↓
Connect to SignalR hub (WebSocket)
      ↓
POST /push/subscription (subscribe to asset data)
      ↓
Receive real-time telemetry and alarm updates

1. Negotiate Connection

Obtain a SignalR connection URL and access token:

curl -X POST https://api.beacontower.ai/push/negotiate \
  -H "Authorization: Bearer $TOKEN"

Response:

{
  "url": "wss://beacon-signalr.service.signalr.net/client/?hub=push",
  "accessToken": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."
}

Use the returned url and accessToken to establish a SignalR client connection.

Once connected, create a subscription to receive updates:

curl -X POST https://api.beacontower.ai/push/subscription \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "connectionId": "your-signalr-connection-id",
    "topic": "telemetry",
    "assets": ["pump-001", "pump-002"],
    "samplingType": "none"
  }'

Field	Type	Required	Description
`connectionId`	string	Yes	Your SignalR connection identifier
`topic`	string	Yes	`"telemetry"` or `"alarm"`
`assets`	string[]	Yes	Asset IDs to monitor
`samplingType`	string	Yes	`"none"` (all updates) or `"first"` (first per interval)

Response:

{
  "subscriptionId": "sub-12345",
  "expiresAt": "2026-02-25T15:13:00Z"
}

3. Manage Subscriptions

Subscriptions have a TTL of 600 seconds (10 minutes). Renew them to keep receiving updates.

# Renew
PUT /push/subscription/{subscriptionId}

# Get details
GET /push/subscription/{subscriptionId}

# Unsubscribe
DELETE /push/subscription/{subscriptionId}

Subscription Topics

Topic	Updates
`telemetry`	Telemetry data from subscribed assets
`alarm`	Alarm raised/cleared notifications from subscribed assets

Sampling Types

Type	Behavior	Use Case
`none`	Send all updates immediately	Real-time monitoring, event-driven logic
`first`	Send only the first update per sampling window	Reduced bandwidth, periodic display updates

When to Use SignalR vs MQTT vs REST

SignalR — Browser-based applications, web dashboards, UIs built with JavaScript/TypeScript. Uses WebSocket transport, integrates natively with ASP.NET Core and JavaScript SignalR clients.
MQTT Publishing — Backend services, IoT consumers, system-to-system integration. Uses standard MQTT protocol, works with any MQTT client library.
REST API — Historical analysis, batch queries, aggregated timeseries. Request-response pattern, no persistent connection needed.

Next Steps

MQTT Publishing — Subscribe to asset data over MQTT
REST API — Query historical and latest timeseries data
Telemetry and Timeseries — Full timeseries query reference with aggregation options

Overview​

Connection Flow​

1. Negotiate Connection​

2. Subscribe to Assets​

3. Manage Subscriptions​

Subscription Topics​

Sampling Types​

When to Use SignalR vs MQTT vs REST​

Next Steps​