Environment Variables

Available Environment Variables

The following environment variables are accepted by the router, and they override other configurations that can be set in the router’s configuration file (router.config.yaml):

Name	Accepted Values	Overrides (YAML)
`LOG_LEVEL`	`trace` / `debug` / `info` / `warn` / `error`	`log.level`
`LOG_FORMAT`	`json` / `pretty-tree` / `pretty-compact`	`log.format`
`LOG_FILTER`	`string`	`log.filter`
`GRAPHIQL_ENABLED`	`true` / `false`	`graphiql.enabled`
`PORT`	`number` (port number)	`http.port`
`HOST`	`string` (host name or IP address)	`http.host`
`SUPERGRAPH_FILE_PATH`	`string` (relative or absolute path to a local file)	`supergraph[file].path`
`HIVE_CDN_ENDPOINT`	`string` (full url to Hive CDN supergraph artifact)	`supergraph[hive].endpoint`
`HIVE_CDN_KEY`	`string` (Hive CDN key)	`supergraph[hive].key`
`HIVE_CDN_POLL_INTERVAL`	`string` (human-readable, for example: `10s`)	`supergraph[hive].poll_interval`

In cases where a configuration file (router.config.yaml) is used with environment variables at the same time, environment variables will only override the specific configuration values.

Accessing Environment Variables in Expressions

Beyond using environment variables to override configuration values at startup, you can also access environment variables dynamically within expressions using the env() function.

For detailed documentation on the env() function and its parameters, see the expressions guide.

Additional Variables

In addition, you may specify the following environment variables:

Name	Accepted Values	Description
`ROUTER_CONFIG_FILE_PATH`	`string` (relative or absolute path to a local file)	Overrides the path to the router configuration file.