Dev Tools

Run basil --dev and the server turns on its development conveniences: live reload, detailed error pages, a log panel, and a database inspector.

Live Reload

Every page served in dev mode polls for changes; save a handler and the browser refreshes itself. Combined with no build step, the loop is: edit → save → look.

Error Pages

In dev mode, a failing handler renders a detailed error page — the error class and code, the source line with a caret, and hints. In production, visitors get a generic error page instead (details go to the logs). The generic pages can be replaced with your own via the error_pages config.

The Dev Log

Log from any handler with @basil/log — entries land in the dev panel, not your HTML:

let {dev} = import @basil/log

dev.log(someValue)
dev.log("user", currentUser)
dev.log("uh oh", err, {level: "warn"})   // "info" (default) | "warn"

Every dev.* function is a no-op in production and in plain pars, so it's safe to leave the calls in.

Dev logs are stored in SQLite (configurable):

dev:
  log_database: ./logs/dev_logs.db
  log_max_size: 10MB
  log_truncate_pct: 25

Database Inspector

Dev mode serves a web UI at /__/db for the built-in database: browse tables, run ad-hoc queries, download tables as CSV, and upload CSVs back.

Request Logging

Requests are logged to the configured output (logging.output); use --quiet to silence them. Handler log() output goes to logging.parsley.output.

Dev Mode vs Production

	`basil --dev`	`basil`
Protocol	HTTP on localhost	HTTPS (see Deployment)
Live reload	✓	—
Error pages	Detailed	Generic
Response caching	Off (`dev.cache` turns it on)	On
Edits to handlers and components	Picked up on the next request	On the next deploy or restart
Dev log & inspector	✓	—