lib/chains.ts:107-117 builds the RPC list with Infura first and the configured override second:
[chain.arbitrum.id]: [
`https://arbitrum-mainnet.infura.io/v3/${INFURA_KEY}`,
process.env.NEXT_PUBLIC_L2_RPC_URL,
].filter(Boolean)viem's fallback() prefers the first entry and only rolls over on failure, so setting NEXT_PUBLIC_L2_RPC_URL makes the custom endpoint a backup to Infura rather than a replacement. Traffic keeps going to mainnet Infura.
That blocks local fork testing: pointing the explorer at anvil --fork-url … --chain-id 42161 has no effect. Blanking INFURA_KEY is not an option either — lib/chains.ts:21 throws without it.
Fix
When NEXT_PUBLIC_L2_RPC_URL (and the L1 equivalent) is set, put it first, or make it exclusive.
Unblocks testing flows that should not touch mainnet — treasury proposal creation and the transaction-lifecycle work in #739 both need it.
Related
#664 — wagmi config missing transports, same area.
lib/chains.ts:107-117builds the RPC list with Infura first and the configured override second:viem's
fallback()prefers the first entry and only rolls over on failure, so settingNEXT_PUBLIC_L2_RPC_URLmakes the custom endpoint a backup to Infura rather than a replacement. Traffic keeps going to mainnet Infura.That blocks local fork testing: pointing the explorer at
anvil --fork-url … --chain-id 42161has no effect. BlankingINFURA_KEYis not an option either —lib/chains.ts:21throws without it.Fix
When
NEXT_PUBLIC_L2_RPC_URL(and the L1 equivalent) is set, put it first, or make it exclusive.Unblocks testing flows that should not touch mainnet — treasury proposal creation and the transaction-lifecycle work in #739 both need it.
Related
#664 — wagmi config missing transports, same area.