> ## 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.

# Requests & Limits

> API variables and info

<Info>
  The Blockscout PRO API is a multichain API with enhanced limits based on your plan (5 rps included in the free plan). Check our [PRO API docs](/devs/pro-api) for more info. Note that per-instance API access will be deprecated soon.
</Info>

* This table scrolls horizontally
* Default API rate limit is 3 requests per second without an API key
* Per-instance API access will be deprecated soon, please switch to using the [PRO API](/devs/pro-api-routes).

| **Type of API key**              | **Rate limit value, req/sec** | **API key is defined by env variable (if applicable)** | **Rate limit for the API key managed by env variable**                                | **Description**                                                                                                                                                                                                                           |
| -------------------------------- | ----------------------------- | ------------------------------------------------------ | ------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| No API key (by IP)               | 3                             |                                                        | `API_RATE_LIMIT_BY_IP` & `API_RATE_LIMIT_BY_IP_TIME_INTERVAL`                         | The default rate limit is 300 requests per minute. This limit applies to all requests that are not from whitelisted addresses and do not use an API key.                                                                                  |
| Temp token                       | 3                             |                                                        | `API_RATE_LIMIT_UI_V2_WITH_TOKEN` & `API_RATE_LIMIT_UI_V2_WITH_TOKEN_TIME_INTERVAL`   | When frontend user reaches the default IP limit, they must solve a captcha to obtain a temporary token. This token provides a personal (not per-IP) rate limit of 5 req/sec. Token TTL is configured via `API_RATE_LIMIT_UI_V2_TOKEN_TTL` |
| Individual API key               | 10                            |                                                        | `API_RATE_LIMIT_BY_ACCOUNT_API_KEY_TIME_INTERVAL`                                     | An API key can be [created by the user in the My Account section](/using-blockscout/my-account/api-keys)                                                                                                                                  |
| Rate limit, if IP is whitelisted | 25                            | `API_RATE_LIMIT_WHITELISTED_IPS`                       | `API_RATE_LIMIT_BY_WHITELISTED_IP` & `API_RATE_LIMIT_BY_WHITELISTED_IP_TIME_INTERVAL` | Rate limit for requests from whitelisted IPs                                                                                                                                                                                              |
| Per explorer instance API key    | 10                            | `API_RATE_LIMIT_STATIC_API_KEY`                        | `API_RATE_LIMIT_BY_KEY` & `API_RATE_LIMIT_BY_KEY_TIME_INTERVAL`                       | A per-instance API key (*this feature was created before individual API keys existed and may have limited utility*)                                                                                                                       |
| No rate limit API key            | ♾️                            | `API_NO_RATE_LIMIT_API_KEY`                            |                                                                                       | Administrator API key                                                                                                                                                                                                                     |

<Check>
  The default rate limit config of each API endpoint is described [in the codebase](https://github.com/blockscout/blockscout/blob/master/apps/block_scout_web/priv/rate_limit_config.json) and can be re-defined via `API_RATE_LIMIT_CONFIG_URL` env variable. [Here](https://github.com/blockscout/blockscout/blob/master/apps/block_scout_web/rate_limits.md) you can find details on the rate limits config.
</Check>

Some of the API endpoints have their own rate limit before showing captcha to the user:

| **API endpoint**                                         | **Number of requests per period** | **Period** |
| -------------------------------------------------------- | --------------------------------- | ---------- |
| `api/v2/key`                                             | ♾️                                |            |
| `api/v2/import/token-info`                               | ♾️                                |            |
| `api/v2/import/smart-contracts/:param`                   | ♾️                                |            |
| `api/account/v2/authenticate_via_wallet`                 | 1                                 | 1 hour     |
| `api/account/v2/send_otp`                                | 1                                 | 1 hour     |
| `api/v2/tokens/:param/instances/:param/refetch-metadata` | 50                                | 1 hour     |
| `api/v2/advanced-filters/csv`                            | 50                                | 1 hour     |
| `api/v2/tokens/:param/holders/csv`                       | 50                                | 1 hour     |
| `api/v2/addresses/:param/transactions/csv`               | 50                                | 1 hour     |
| `api/v2/addresses/:param/token-transfers/csv`            | 50                                | 1 hour     |
| `api/v2/addresses/:param/internal-transactions/csv`      | 50                                | 1 hour     |
| `api/v2/addresses/:param/logs/csv`                       | 50                                | 1 hour     |
| `api/v2/addresses/:param/election-rewards/csv`           | 50                                | 1 hour     |
| `api/v2/smart-contracts/:param/audit-reports`            | 50                                | 1 hour     |
| `api/health/*`                                           | 5                                 | 1 second   |