LightHouse

Self-hosted push notification server implementing the Skyglow Protocol v2 (SGP/2). Pairs with the Skyglow Notifications Client to deliver notifications over a persistent TLS connection, replacing Apple Push Notification Service on legacy devices.

Requirements

• Java 21+
• PostgreSQL
• OpenSSL (for certificate generation)

Setup

1. Generate the server certificate:

./generate-certificate.sh server --name your.domain.com

This creates cert.pem and key.pem in the current directory.

Tip

To restrict device registration to authorized operators, generate a registration CA and issue client certificates:

./generate-certificate.sh ca
./generate-certificate.sh client --name alice

2. Configure environment variables:

Variable	Description	Default
SGP_CERT_PATH	TLS certificate PEM	required
SGP_KEY_PATH	TLS key PEM (unencrypted PKCS#8)	required
SGP_DB_URL	PostgreSQL JDBC URL	required
SGP_DB_USER	Database user	required
SGP_DB_PASS	Database password	required
SGP_SERVER_ADDRESS	Public domain for this server	required
SGP_TCP_PORT	SGP/2 listener port	7373
SGP_HTTP_PORT	HTTP API port	7878
SGP_HTTP_BIND	HTTP bind address	127.0.0.1
SGP_TLS_MIN	Minimum TLS version (1.2 or 1.3)	1.3
SGP_REG_CA_PATH	Registration CA PEM (optional)	open registration

3. Build:

mvn package -DskipTests

4. Run:

java -jar target/LightHouse-1.0-SNAPSHOT.jar

HTTP API

Method	Path	Description
POST	/send	Send a notification to a device by routing key
GET	/health	Server status and connected device count
GET	/snd/server_cert.pem	Download the server certificate for client pinning

Documentation

Client can be hound here.

Protocol Documentation can be found here.