Configuration

The driver reads config.json from the application root:

Bundled executable: next to plato-printer.exe.
Development: current working directory.

If config.json is missing, the driver creates one with sanitized defaults.

Example Config

{
  "server": {
    "port": 8080
  },
  "features": {
    "meshEnabled": true,
    "httpsEnabled": true
  },
  "caddy": {
    "enabled": true,
    "domain": "plato-printer.local",
    "httpsPort": 443,
    "version": "2.6.4"
  },
  "redis": {
    "mode": "embedded",
    "version": "6.2.14",
    "host": "127.0.0.1",
    "port": 6379,
    "db": 0,
    "username": "",
    "password": "",
    "diskSync": true,
    "snapshotIntervalSec": 30
  },
  "queue": {
    "retryDelayMs": 5000,
    "maxAttempts": 2147483647
  }
}

Server

Field	Default	Notes
`server.port`	`8080`	HTTP port for all API endpoints.

The Express app enables permissive CORS and Access-Control-Allow-Private-Network: true so browser POS clients can call the driver from local/private networks.

Features

Field	Default	Notes
`features.meshEnabled`	`true`	Enables PeerJS signaling on `/mesh`.
`features.httpsEnabled`	`true`	Allows HTTPS setup when Caddy is also enabled.

HTTPS only starts when both features.httpsEnabled and caddy.enabled are true.

Caddy

Field	Default	Notes
`caddy.enabled`	`true`	Enables the Caddy reverse proxy path.
`caddy.domain`	`plato-printer.local`	Hostname used for HTTPS.
`caddy.httpsPort`	`443`	HTTPS listener port.
`caddy.version`	`2.6.4`	Pinned for Windows 7 compatibility.

On Windows 7 or older, the driver rejects HTTPS configs that use a Caddy version other than 2.6.4.

Redis

Field	Default	Notes
`redis.mode`	`embedded`	`embedded` starts Redis from the driver; `external` uses an existing Redis server.
`redis.version`	`6.2.14`	Required embedded Redis version.
`redis.host`	`127.0.0.1`	Redis bind/connect host.
`redis.port`	`6379`	Redis port.
`redis.db`	`0`	Redis database number.
`redis.username`	empty	Used for external Redis auth when set.
`redis.password`	empty	Used for external Redis auth when set.
`redis.diskSync`	`false` generated default	Writes Redis snapshots to `dump.rdb` when true. The committed production config sets this to `true`.
`redis.snapshotIntervalSec`	`30`	Snapshot interval used when disk sync is enabled.

Embedded Redis startup aborts the whole driver if Redis cannot start or if the actual Redis version does not match redis.version.

Queue

Field	Default	Notes
`queue.retryDelayMs`	`5000`	Fixed retry backoff for failed print jobs.
`queue.maxAttempts`	`2147483647`	Maximum attempts per job. The current config effectively retries forever.

Sanitization

The config reader sanitizes values:

Ports and numeric settings must be positive integers.
Booleans can be booleans or strings "true" / "false".
redis.mode must be embedded or external.
Empty strings fall back to defaults for domain/version/host-like fields.

​Configuration

​Example Config

​Server

​Features

​Caddy

​Redis

​Queue

​Sanitization