Networks | Hedera — BizFirstAI

Network	Mirror REST URL	Use For
`mainnet`	`https://mainnet-public.mirrornode.hedera.com`	Production. Real HBAR, real fees on any future write operations.
`testnet`	`https://testnet.mirrornode.hedera.com`	Default network. Free faucet HBAR available — safe for development and CI.
`previewnet`	`https://previewnet.mirrornode.hedera.com`	Early-access features not yet on testnet/mainnet.

Testnet faucet: Hedera provides a public testnet faucet for free HBAR, so you can exercise account/token/topic operations end to end without spending real funds. Point DefaultNetwork at testnet (the default) while developing.

How Network Selection Works

Each operation call may include a network config key.
If set, the node resolves that network's MirrorRestUrl from Hedera:Networks and calls it.
If unset, the node uses whatever Hedera:DefaultNetwork points to.
If the resolved network name has no matching entry under Hedera:Networks, the node throws HederaNetworkNotConfiguredException rather than silently falling back.

Adding a Custom Network

Add any additional entry under Hedera:Networks — the key becomes the value workflows pass in the network field:

"Hedera": {
  "DefaultNetwork": "testnet",
  "Networks": {
    "testnet":     { "MirrorRestUrl": "https://testnet.mirrornode.hedera.com" },
    "my-local-net": { "MirrorRestUrl": "https://mirror.my-internal-hedera-net.example" }
  }
}

No code change or redeploy of the node itself is required — this is a pure configuration addition.

Only Mirror Node URLs are configurable here. This node's current operations are all Mirror Node REST reads, so the only per-network setting needed is MirrorRestUrl. Signed write operations (see Roadmap) will need consensus node endpoints too, once implemented.