> ## Documentation Index
> Fetch the complete documentation index at: https://docs.archivecircle.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Environment variables

> Configure database, Redis, storage, email, auth, and Arc billing settings.

Eternum reads configuration from environment variables. Keep production secrets outside git.

## Required categories

| Category | Examples                                                        |
| -------- | --------------------------------------------------------------- |
| Database | `DB_HOST`, `DB_USER`, `DB_PASSWORD`                             |
| Redis    | `REDIS_HOST`, `RELEASE_REDIS_HOST`                              |
| Storage  | `MINIO_ENDPOINT`, `MINIO_ACCESS_KEY`, `MINIO_SECRET_KEY`        |
| Auth     | `JWT_SECRET`, `REFRESH_TOKEN_SECRET`                            |
| Email    | `EMAIL_PROVIDER`, `RESEND_API_KEY`, `EMAIL_FROM`                |
| Billing  | `ARC_RECEIVING_ADDRESS`, `ARC_RPC_URL`, `USDC_CONTRACT_ADDRESS` |

## Arc Testnet defaults

```text theme={null}
ARC_RECEIVING_ADDRESS=0x7F91Fb08A0A94b27ad57a4F4283945b1407FFb6D
ARC_RPC_URL=https://rpc.testnet.arc.network
ARC_CHAIN_ID=5042002
USDC_CONTRACT_ADDRESS=0x3600000000000000000000000000000000000000
```

The frontend also uses public equivalents for wallet and billing configuration:

```text theme={null}
NEXT_PUBLIC_ARC_RECEIVING_ADDRESS=0x7F91Fb08A0A94b27ad57a4F4283945b1407FFb6D
NEXT_PUBLIC_ARC_CHAIN_ID=5042002
NEXT_PUBLIC_USDC_CONTRACT_ADDRESS=0x3600000000000000000000000000000000000000
```

<Warning>
  Rotate any production secret that was ever committed, copied into logs, or shared in a public channel.
</Warning>