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

# Deprecated Frontend ENVs

> Reference of deprecated Blockscout frontend environment variables, their replacements, defaults, and versions where each was removed.

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# Deprecated environment variables

| Variable | Type | Description | Compulsoriness | Default value | Example value | Introduced in version | Deprecated in version | Comment |
| - | - | - | - | - | - | - | - | - |
| NEXT\_PUBLIC\_FAVICON\_GENERATOR\_API\_KEY `deprecated` | `string` | RealFaviconGenerator [API key](https://realfavicongenerator.net/api/) | Required | - | `<your-secret>` | v1.11.0 | v1.16.0 | Replaced FAVICON\_GENERATOR\_API\_KEY |
| FAVICON\_GENERATOR\_API\_KEY `deprecated` | `string` | RealFaviconGenerator [API key](https://realfavicongenerator.net/api/) | Required | - | `<your-secret>` | v1.16.0+ | v1.37.0 | We don't use RealFaviconGenerator anymore |
| NEXT\_PUBLIC\_IS\_OPTIMISTIC\_L2\_NETWORK `deprecated` | `boolean` | Set to true for optimistic L2 solutions | Required | - | `true` | v1.17.0 | v1.24.0 | Replaced by NEXT\_PUBLIC\_ROLLUP\_TYPE |
| NEXT\_PUBLIC\_IS\_ZKEVM\_L2\_NETWORK `deprecated` | `boolean` | Set to true for zkevm L2 solutions | Required | - | `true` | v1.17.0 | v1.24.0 | Replaced by NEXT\_PUBLIC\_ROLLUP\_TYPE |
| NEXT\_PUBLIC\_OPTIMISTIC\_L2\_WITHDRAWAL\_URL `deprecated` | `string` | URL for optimistic L2 -> L1 withdrawals | Required | - | `https://app.optimism.io/bridge/withdraw` | v1.17.0 | v1.24.0 | Renamed to NEXT\_PUBLIC\_ROLLUP\_L2\_WITHDRAWAL\_URL |
| NEXT\_PUBLIC\_L1\_BASE\_URL `deprecated` | `string` | Blockscout base URL for L1 network | Required | - | `'http://eth-goerli.blockscout.com'` | - | v1.24.0 | Renamed to NEXT\_PUBLIC\_ROLLUP\_L1\_BASE\_URL |
| NEXT\_PUBLIC\_HOMEPAGE\_SHOW\_GAS\_TRACKER `deprecated` | `boolean` | Set to false if network doesn't have gas tracker | - | `true` | `false` | - | v1.25.0 | Replaced by NEXT\_PUBLIC\_GAS\_TRACKER\_ENABLED |
| NEXT\_PUBLIC\_NETWORK\_GOVERNANCE\_TOKEN\_SYMBOL `deprecated` | `string` | Network governance token symbol | - | - | `GNO` | v1.12.0 | v1.29.0 | Replaced by NEXT\_PUBLIC\_NETWORK\_SECONDARY\_COIN\_SYMBOL |
| NEXT\_PUBLIC\_SWAP\_BUTTON\_URL `deprecated` | `string` | Application ID in the marketplace or website URL | - | - | `uniswap` | v1.24.0 | v1.31.0 | Replaced by NEXT\_PUBLIC\_DEFI\_DROPDOWN\_ITEMS |
| NEXT\_PUBLIC\_HOMEPAGE\_SHOW\_AVG\_BLOCK\_TIME `deprecated` | `boolean` | Set to false if average block time is useless for the network | - | `true` | `false` | v1.0.x+ | v1.35.0 | Replaced by NEXT\_PUBLIC\_HOMEPAGE\_STATS |
| NEXT\_PUBLIC\_CELO\_L2\_UPGRADE\_BLOCK `deprecated` | `number` | Indicates the block number when the Celo-type chain transitioned to L2. This is used to display links to the Epoch block page from a regular block page. | - | - | `26369280` | v1.37.0+ | v2.2.0 | Removed; configuration done on the API side |
| NEXT\_PUBLIC\_NAVIGATION\_HIDDEN\_LINKS `deprecated` | `Array<LinkId>` | List of external links hidden in the navigation. Supported ids are `eth_rpc_api`, `rpc_api` | - | - | `['eth_rpc_api']` | v1.16.0+ | v2.3.0 | Use NEXT\_PUBLIC\_API\_DOCS\_TABS instead to hide tabs on the API docs page. |


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