| `ETHEREUM_JSONRPC_FALLBACK_WS_URL` | The fallback WebSockets RPC endpoint used to subscribe to the `newHeads` subscription alerting the indexer to fetch new blocks. Implemented in [#10407](https://github.com/blockscout/blockscout/pull/10407). | <p>Version: v6.8.0+<br>Default: (empty)<br>Applications: Indexer</p> |
| `ETHEREUM_JSONRPC_WS_RETRY_INTERVAL` | The interval between retries of connecting to WebSocket RPC endpoint after the previous attempt is failed. Implemented in [#10407](https://github.com/blockscout/blockscout/pull/10407). | <p>Version: v6.8.0+<br>Default: 1m<br>Applications: Indexer</p> |
| `DATABASE_EVENT_URL` | Variable to define the Postgres Database endpoint that will be used by event listener process. Applicable for separate indexer and API setup. More info in related PR. Implemented in [#10164](https://github.com/blockscout/blockscout/pull/10164). | <p>Version: v6.8.0+<br>Default: (empty)<br>Applications: API</p> |
| `PUBLIC_METRICS_ENABLED` | Variable to enable running queries at /public-metrics endpoint. Implemented in [#10469](https://github.com/blockscout/blockscout/pull/10469). | <p>Version: v6.8.0+<br>Default: false<br>Applications: API</p> |
| `PUBLIC_METRICS_UPDATE_PERIOD_HOURS` | Public metrics update period in hours at /public-metrics endpoint. Implemented in [#10469](https://github.com/blockscout/blockscout/pull/10469). | <p>Version: v6.8.0+<br>Default: 24<br>Applications: API</p> |
| `SHRINK_INTERNAL_TRANSACTIONS_ENABLED` | Variable to enable internal transactions shrinking logic. Implemented in [#10567](https://github.com/blockscout/blockscout/pull/10567). | <p>Version: v6.8.0+<br>Default: <code>false</code><br>Applications: API, Indexer</p> |
| `SHRINK_INTERNAL_TRANSACTIONS_BATCH_SIZE` | Batch size of the shrink internal transactions migration. Implemented in [#10567](https://github.com/blockscout/blockscout/pull/10567). | <p>Version: v6.8.0+<br>Default: 1000<br>Applications: API, Indexer</p> |
| `SHRINK_INTERNAL_TRANSACTIONS_CONCURRENCY` | Concurrency of the shrink internal transactions migration. Implemented in [#10567](https://github.com/blockscout/blockscout/pull/10567). | <p>Version: v6.8.0+<br>Default: 1<br>Applications: API, Indexer</p> |
| `IPFS_PUBLIC_GATEWAY_URL` | IPFS public gateway url which is used by frontend to display IPFS resources such as token instance image. | <p>Version: v6.8.0+<br>Default: <code>https://ipfs.io/ipfs</code><br>Applications: API</p> |
| `INDEXER_TOKEN_INSTANCE_RETRY_MAX_REFETCH_INTERVAL` | Maximum interval between attempts to fetch token instance metadata. [Time format](backend-env-variables.md#time-format). Implemented in [#10027](https://github.com/blockscout/blockscout/pull/10027). | <p>Version: v6.8.0+<br>Default: <code>168h</code><br>Applications: Indexer</p> |
| `INDEXER_TOKEN_INSTANCE_RETRY_EXPONENTIAL_TIMEOUT_BASE` | Base to calculate exponential timeout. Implemented in [#10027](https://github.com/blockscout/blockscout/pull/10027). | <p>Version: v6.8.0+<br>Default: <code>2</code><br>Applications: Indexer</p> |
| `INDEXER_TOKEN_INSTANCE_RETRY_EXPONENTIAL_TIMEOUT_COEFF` | Coefficient to calculate exponential timeout. Implemented in [#10027](https://github.com/blockscout/blockscout/pull/10027). | <p>Version: v6.8.0+<br>Default: <code>100</code><br>Applications: Indexer</p> |
| `MISSING_BALANCE_OF_TOKENS_WINDOW_SIZE` | Minimal blocks count until the next token balance request will be executed for tokens that doesn't implement `balanceOf` function. Implemented in [#10142](https://github.com/blockscout/blockscout/pull/10142) | <p>Version: v6.8.0+<br>Default: <code>100</code><br>Applications: Indexer</p> |
| `ETHEREUM_JSONRPC_GETH_ALLOW_EMPTY_TRACES` | Allow transactions to not have internal transactions. Implemented in [#10200](https://github.com/blockscout/blockscout/pull/10200) | <p>Version: v6.8.0+<br>Default: <code>false</code><br>Applications: Indexer</p> |
| `INDEXER_DISABLE_REPLACED_TRANSACTION_FETCHER` | If `true`, `Indexer.Fetcher.ReplacedTransaction` fetcher doesn't run | <p>Version: v6.8.0+<br>Default: <code>false</code><br>Applications: Indexer</p> |
| `SANITIZE_INCORRECT_WETH_BATCH_SIZE` | Number of token transfers to sanitize in the batch. Implemented in [#10134](https://github.com/blockscout/blockscout/pull/10134) | <p>Version: v6.8.0+<br>Default: <code>100</code><br>Applications: API, Indexer</p> |
| `SANITIZE_INCORRECT_WETH_CONCURRENCY` | Number of parallel sanitizing token transfer batches processing. Implemented in [#10134](https://github.com/blockscout/blockscout/pull/10134) | <p>Version: v6.8.0+<br>Default: <code>1</code><br>Applications: API, Indexer</p> |
| `MIGRATION_RESTORE_OMITTED_WETH_TOKEN_TRANSFERS_BATCH_SIZE` | Number of logs to process in the batch. Implemented in [#10466](https://github.com/blockscout/blockscout/pull/10466) | <p>Version: v6.8.0+<br>Default: <code>50</code><br>Applications: API, Indexer</p> |
| `MIGRATION_RESTORE_OMITTED_WETH_TOKEN_TRANSFERS_CONCURRENCY`| Number of parallel logs batches processing. Implemented in [#10466](https://github.com/blockscout/blockscout/pull/10466) | <p>Version: v6.8.0+<br>Default: <code>5</code><br>Applications: API, Indexer</p> |
| `MIGRATION_RESTORE_OMITTED_WETH_TOKEN_TRANSFERS_TIMEOUT` | Time interval between checks if queue are not empty. The same timeout multiplied by 2 used between checks if qeueue are not full. Implemented in [#10466](https://github.com/blockscout/blockscout/pull/10466) | <p>Version: v6.8.0+<br>Default: <code>250ms</code><br>Applications: API, Indexer</p> |
| `EXCHANGE_RATES_SOURCE` | Source for native coin and tokens price fetching. Possible values are: `coin_gecko`, `coin_market_cap` or `mobula`. | <p>Version: v6.8.0+<br>Default: <code>coin_gecko</code><br>Applications: API, Indexer</p> |
| `EXCHANGE_RATES_SECONDARY_COIN_SOURCE` | Source for secondary coin fetching. Possible values are: `coin_gecko`, `coin_market_cap` or `mobula`. | <p>Version: v6.8.0+<br>Default: <code>coin_gecko</code><br>Applications: API, Indexer</p> |
| `TOKEN_EXCHANGE_RATES_SOURCE` | Sets the source for tokens price fetching. Available values are `coin_gecko`, `cryptorank`. Implemented in [#10550](https://github.com/blockscout/blockscout/pull/10550). | <p>Version: v6.8.0+<br>Default: <code>coin_gecko</code><br>Applications: API, Indexer</p> |
| `EXCHANGE_RATES_CRYPTORANK_SECONDARY_COIN_ID` | Sets Cryptorank coin ID for secondary coin market chart. Implemented in [#10550](https://github.com/blockscout/blockscout/pull/10550). | <p>Version: v6.8.0+<br>Default: (empty)<br>Applications: API, Indexer</p> |
| `EXCHANGE_RATES_CRYPTORANK_BASE_URL` | If set, overrides the Cryptorank API url. Implemented in [#10550](https://github.com/blockscout/blockscout/pull/10550). | <p>Version: v6.8.0+<br>Default: <code>https://api.cryptorank.io/v1/</code><br>Applications: API, Indexer</p> |
| `EXCHANGE_RATES_CRYPTORANK_API_KEY` | Cryptorank API key. Current implementation uses dedicated beta Cryptorank API endpoint. If you want to integrate Cryptorank price fetching you should contact Cryptorank to receive an API key. Implemented in [#10550](https://github.com/blockscout/blockscout/pull/10550). | <p>Version: v6.8.0+<br>Default: (empty)<br>Applications: API, Indexer</p> |
| `EXCHANGE_RATES_CRYPTORANK_LIMIT` | Sets the maximum number of token prices returned in a single request. Implemented in [#10550](https://github.com/blockscout/blockscout/pull/10550). | <p>Version: v6.8.0+<br>Default: <code>1000</code><br>Applications: API, Indexer</p> |
| `WHITELISTED_WETH_CONTRACTS` | Comma-separated list of smart-contract address hashes of WETH-like tokens which deposit and withdrawal events you'd like to index. Implemented in [#10134](https://github.com/blockscout/blockscout/pull/10134) | <p>Version: v6.8.0+<br>Default: (empty)<br>Applications: API, Indexer</p> |
| `API_NO_RATE_LIMIT_API_KEY` | API key with no rate limit. Implemented in [#10515](https://github.com/blockscout/blockscout/pull/10515) | <p>Version: v6.8.0+<br>Default: (empty)<br>Applications: API</p> |