Configuration Reference

Every configurable Copper package reads its own TOML table from your config files. All keys are optional; sensible defaults apply when a key, or the whole table, is missing. To learn how config files are loaded and layered, see Configuration.

Command-Line Flags

Every Copper binary accepts two flags:

Flag	Default	Description
`-config`	`./config/dev.toml`	Path to the config file
`-set`	—	Inline overrides, e.g. `-set "chttp.port=5902"`. Values are parsed as TOML, so quote strings: `-set 'csql.dialect="pgx"'`. Separate multiple with `;`

[chttp]

Key	Type	Default	Description
`port`	uint	`7501`	HTTP server port (`copper create` sets `5901` in generated config)
`read_timeout_seconds`	uint	`10`	`http.Server` read timeout
`use_local_html`	bool	`false`	Read templates and static files from `./web` on disk instead of the embedded copies — for development
`render_html_error`	bool	`false`	Render a detailed error page in the browser — for development
`enable_single_page_routing`	bool	`false`	Serve `index.html` for all unmatched GET routes (SPA mode)
`redirect_url_for_unauthorized_requests`	string	—	Where `HTMLReaderWriter.Unauthorized` redirects; plain `401` if unset
`base_path`	string	—	Mount the app under a path prefix

[clogger]

Key	Type	Default	Description
`out`	string	stdout	File path for debug/info logs
`err`	string	stderr	File path for warn/error logs
`format`	string	`plain`	`plain` or `json`
`level_filter`	[]string	all	Allow-list of levels to log, e.g. `["info", "error"]`
`redact_fields`	[]string	—	Tag field names to redact — JSON format only

[csql]

Key	Type	Default	Description
`dialect`	string	—	`postgres`, `pgx`, `sqlite3`, or `mysql`
`dsn`	string	—	Database connection string
`max_open_connections`	int	`25`	Connection pool: max open connections
`max_idle_connections`	int	`25`	Connection pool: max idle connections
`conn_max_lifetime_mins`	int	`5`	Connection pool: max connection lifetime in minutes

[csql.migrations]

Key	Type	Default	Description
`direction`	string	`up`	`up` applies all pending migrations; `down` rolls back one
`source`	string	`embed`	`embed` reads migrations from the binary; `dir` reads `./migrations` from disk

[aws]

Used by cmailer’s AWS SES backend. See Sending Email.

Key	Type	Default	Description
`region`	string	—	AWS region
`access_key_id`	string	—	AWS access key ID
`secret_access_key`	string	—	AWS secret access key

[inertia]

Key	Type	Default	Description
`ssr`	bool	`false`	Render pages via an Inertia SSR server
`ssr_server`	string	`http://localhost:13714`	SSR server URL

[vitejs]

Key	Type	Default	Description
`dev_mode`	bool	`false`	Load assets from the Vite dev server with HMR
`host`	string	`http://localhost:3000`	Vite dev server URL

[cprometheus]

Key	Type	Default	Description
`http_enabled`	bool	`false`	Serve the Prometheus metrics endpoint
`http_path`	string	`/internal/metrics`	Path for the metrics endpoint

Getting Started

The Basics

Architecture

HTTP

Database

Frontend

Digging Deeper

Reference

Configuration Reference

Command-Line Flags

[chttp]

[clogger]

[csql]

[csql.migrations]

[aws]

[inertia]

[vitejs]

[cprometheus]

​Command-Line Flags

​[chttp]

​[clogger]

​[csql]

​[csql.migrations]

​[aws]

​[inertia]

​[vitejs]

​[cprometheus]

Command-Line Flags

[chttp]

[clogger]

[csql]

[csql.migrations]

[aws]

[inertia]

[vitejs]

[cprometheus]