Configuration

1. Environment Variables

Source: @nx/core environment keys + this package's common/. Signal uses the standard VerifierApplication keys plus WebSocket-, Redis-, and Kafka-specific ones below.

Application & Identity

Name	Type	Default	Required	Description
APP_ENV_APPLICATION_NAME	string	—	✓	Service identifier
APP_ENV_SERVER_PORT	number	3000		HTTP listen port (dev 31090)
APP_ENV_SERVER_BASE_PATH	string	/v1/api		Route prefix (effective base /v1/api/signal)
APP_ENV_IDENTITY_SERVICE_BASE_URL	string	—	✓	Identity base URL for JWKS verification
APP_ENV_JWKS_REST_PATH	string	/jw-certs		JWKS endpoint path
APP_ENV_SNOWFLAKE_WORKER_ID	number	9		Snowflake worker ID

Database (core datasource)

Name	Type	Default	Required	Description
APP_ENV_POSTGRES_*	—	—	✓	Standard core Postgres keys (notification persistence + authz)

WebSocket — ECDH

Name	Type	Default	Required	Description
APP_ENV_WEBSOCKET_ECDH_INFO	string	—	✓	HKDF info string; must match the client-side value

WebSocket — Redis (pub/sub bus)

Name	Type	Default	Required	Description
APP_ENV_WEBSOCKET_REDIS_MODE	single | cluster	single		Connection mode
APP_ENV_WEBSOCKET_REDIS_HOST	string	localhost		Host (single mode)
APP_ENV_WEBSOCKET_REDIS_PORT	number	6379		Port (single mode)
APP_ENV_WEBSOCKET_REDIS_DB	number	0		DB index (single mode)
APP_ENV_WEBSOCKET_REDIS_PASSWORD	string	—		Password
APP_ENV_WEBSOCKET_REDIS_MAX_RETRY	number	5		Max retry (single mode)
APP_ENV_WEBSOCKET_REDIS_CLUSTER_NODES	string	—	cluster	Comma-separated host:port pairs (required in cluster mode)

This is the only Redis Signal uses — there is no separate cache/queue Redis. All publishers (Signal + emitter services) must point at the same instance/cluster.

Kafka — activity-notification consumer

Name	Type	Default	Required	Description
APP_ENV_KAFKA_BROKERS	string	—	✓	Comma-separated brokers; empty/unset → fail-fast at boot
APP_ENV_KAFKA_CLIENT_ID	string	SVC-00090-SIGNAL_NOTIF_CONSUMER		Consumer client id
APP_ENV_KAFKA_GROUP_ID	string	SVC-00090-SIGNAL_NOTIF_CONSUMER_GROUP		Consumer group id
APP_ENV_KAFKA_SASL_ENABLE	boolean	false		Enable SASL
APP_ENV_KAFKA_SASL_MECHANISM	string	—	if SASL	e.g. SCRAM-SHA-512
APP_ENV_KAFKA_SASL_USERNAME	string	—	if SASL	—
APP_ENV_KAFKA_SASL_PASSWORD	string	—	if SASL	—

2. Feature Flags

None. Behavior is governed entirely by the env vars above (mode switches: Redis single/cluster, Kafka SASL on/off).

3. Seeded Data

Migration processes in src/migrations/processes/ — alwaysRun: true, idempotent.

File	Seeds	Idempotent	Notes
signal-0001-seed-permissions.ts	WebSocketClient.* permissions (6)	✓	Upserts each SignalPermissions entry by code
signal-0002-seed-role-permissions.ts	Role→permission grants	✓	Grants all signal permissions to OWNER, EMPLOYEE, CASHIER via PolicyDefinition; skips already-granted

Signal has no schema migrations — it owns no tables. These migrations only seed authorization data into @nx/core tables.

4. Configuration Storage (Configuration table)

Not used. Signal holds no per-merchant runtime configuration.

5. Related Pages

• Operations
• Decisions