---
title: Configuring Version 5
permalink: /v5/configuration/
---

The following environment variables can be set to configure the Coral Server. You
can expose them in your shell via `export NODE_ENV=development` or by placing
the variables in a `.env` file in the root of the project in a simple
`NODE_ENV=development` format delimited by newlines.

- `NODE_ENV` - Can be one of `production` or `development`. All production
  deployments should use `production`. Defaults to `production` when ran with
  `npm run start` and `development` when run with `npm run start:development`.
- `PORT` - The port to listen for HTTP and Websocket requests. (Default `3000`)
- `MONGODB_URI` - The MongoDB database URI to connect to.
  (Default `mongodb://127.0.0.1:27017/coral`)
- `REDIS_URI` - The Redis database URI to connect to.
  (Default `redis://127.0.0.1:6379`)
- `REDIS_OPTIONS` - A JSON string with optional configuration options to be used
  when connecting to Redis as specified in the [ioredis](https://github.com/luin/ioredis/blob/1dac50a63753c2afc969315cfe38faf0edc50bc5/API.md#new_Redis_new) documentation.
  (Default: `{}`)
- `SIGNING_SECRET` - The shared secret to use to sign JSON Web Tokens (JWT) with
  the selected signing algorithm. 🚨 **Don't forget to set this variable!** 🚨
  (Default: `keyboard cat`)
- `SIGNING_ALGORITHM` - The signing algorithm to use for signing JWT's.
  (Default `HS256`).
- `LOGGING_LEVEL` - The logging level that can be set to one of `fatal`,
  `error`, `warn`, `info`, `debug`, or `trace`. (Default `info`)
- `STATIC_URI` - The URI that static assets can be accessed from. This URI can
  be to a proxy that uses this Coral server on `PORT` as the upstream. Disabled
  by default.
- `DISABLE_TENANT_CACHING` - When `true`, all tenants will be loaded from the
  database when needed rather than keeping a in-memory copy in sync via
  published events on Redis. (Default `false`)
- `DISABLE_MONGODB_AUTOINDEXING` - When `true`, Coral will not perform indexing
  operations when it starts up. This can be desired when you've already
  installed Coral on the target MongoDB, but want to improve start performance.
  **You should not use this parameter unless you know what you're doing! Upgrades
  may introduce additional indexes that the application relies on.**
  (Default `false`)
- `LOCALE` - Specify the default locale to use for all requests without a locale
  specified. (Default `en-US`)
- `ENABLE_GRAPHIQL` - When `true`, it will enable the `/graphiql` even in
  production, use with care. (Default `false`)
- `CONCURRENCY` - The number of worker nodes to spawn to handle web traffic,
  this should be tied to the number of CPU's available. (Default
  `os.cpus().length`)
- `DEV_PORT` - The port where the Webpack Development server is running on.
  (Default `8080`)
- `METRICS_USERNAME` - The username for _Basic Authentication_ at the `/metrics` and `/cluster_metrics`
  endpoint.
- `METRICS_PASSWORD` - The password for _Basic Authentication_ at the `/metrics` and `/cluster_metrics`
  endpoint.
- `CLUSTER_METRICS_PORT` - If `CONCURRENCY` is more than `1`, the metrics are provided at this port under `/cluster_metrics`. (Default `3001`)
- `DISABLE_LIVE_UPDATES` - When `true`, disables subscriptions for the comment
  stream for all stories across all tenants (Default `false`)
- `WEBSOCKET_KEEP_ALIVE_TIMEOUT` - A duration in a parsable format (e.g. `30 seconds`
  , `1 minute`) that should be used to send keep alive messages through the
  websocket to keep the socket alive (Default `30 seconds`)
- `TRUST_PROXY` - When provided, it configures the "trust proxy" settings for Express (See https://expressjs.com/en/guide/behind-proxies.html)