> ## 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.

# PRO API Responses and Routes

> Blockscout's PRO API provides higher call limits and custom endpoints

<Check>
  Access the dev portal and get a free API key at [https://dev.blockscout.com/](https://dev.blockscout.com/)
</Check>

* [Authorization](https://docs.blockscout.com/#pro-api-authorization)
* [Routes](#pro-api-routes)
* [Pagination](#pagination)
* [Credits](#blockscout-credit-costs)

<Info>
  PRO API endpoints are documented individually in the API Reference menu
</Info>

# PRO API Authorization

Pass an API key using either:

* `apikey` query parameter
* `authorization` header

## PRO API Response Headers

The following information related to the PRO API plan are included in the response headers

* **x-credits-remaining:** Number of credits remaining in your plan. If on the free plan, this will resent daily, othewise it is monthly. You can check additional details in the [PRO API UI](https://dev.blockscout.com/).
* **x-ratelimit-limit:** Available RPS with your plan (can be -1 if there is an internal error)
* **x-ratelimit-remaining:** Remaining rate limit based on your queries  (can be -1 if there is an internal error)
* **x-ratelimit-reset:** time in milliseconds until the rate limit resets (can be -1 if there is an internal error)

<Frame>
  <img src="https://mintcdn.com/blockscout/VM0y03Br-QMpZ_wK/images/Screenshot2026-03-04at1.29.00PM.png?fit=max&auto=format&n=VM0y03Br-QMpZ_wK&q=85&s=f1ecc31ea268dc7a0ebcc7defc92bf04" alt="Screenshot2026 03 04at1 29 00PM" width="1108" height="502" data-path="images/Screenshot2026-03-04at1.29.00PM.png" />
</Frame>

# PRO API Routes

All current API routes can be used with the PRO Plan. See the PRO API Endpoints section to try example calls with your API key.

The Route examples below use the Optimism chain (chain\_id=10). In Previous per-instance routes API keys are optional for the free tier, they are required for all tiers (including the free tier) of the PRO API.

## **JSON PRC API v2 (compare to Etherscan PRO API)**

PRO API Route :

```text wrap theme={null}
https://api.blockscout.com/v2/api?chain_id=10&module=block&action=eth_block_number&apikey=proapi_xxxxxxxx
```

Previous per-instance route:

<Warning>
  `https://optimism.blockscout.com/api?module=block&action=eth_block_number`
</Warning>

## **JSON RPC API**

PRO API Route:

```text wrap theme={null}
https://api.blockscout.com/10/api?module=account&action=eth_get_balance&address={addressHash}&apikey=proapi_xxxxxxx
```

Previous per-instance route:

<Warning>
  `https://optimism.blockscout.com/api?module=account&action=eth_get_balance&address={addressHash}`
</Warning>

## **REST API**

PRO API Route:

```text wrap theme={null}
https://api.blockscout.com/10/api/v2/blocks/{block_number_or_hash}?apikey=proapi_xxxxxxxx
```

Previous per-instance route:

<Warning>
  `https://optimism.blockscout.com/api/v2/blocks/{block_number_or_hash}`
</Warning>

## **ETH RPC API**

see [ETH RPC docs](/devs/apis/rpc/eth-rpc) for more info on post requests.

PRO API Route

```text theme={null}
curl -H "content-type: application/json" \
  -H "authorization: Bearer proapi_xxxxxx" \
  -X POST \
  --data '{"id":0,"jsonrpc":"2.0","method":"eth_blockNumber","params":[]}' \
  https://api.blockscout.com/10/json-rpc
```

<Note>
  Please see the [API reference section](/devs/apis) for specific endpoint info related to the various API routes.
</Note>

# Pagination

Blockscout uses the keyset pagination method to quickly return results. By default an API response returns the first 50 results. To access additional results (in groups of 50), add the `next_page_params` to your query.

For example, open [**https://api.blockscout.com/10/api/v2/transactions?apikey=proapi\_xxxxxx**](https://api.blockscout.com/10/api/v2/transactions?apikey=proapi_xxxxxx) and scroll to the bottom of the response.

<Frame caption="Example response from transactions query">
  <img src="https://mintcdn.com/blockscout/hSpk2S3pm3N4c9cZ/images/tx-pagination-1.jpg?fit=max&auto=format&n=hSpk2S3pm3N4c9cZ&q=85&s=c4460dc59fa7fe90637200940b93cf5f" alt="Tx Pagination 1" width="1524" height="1116" data-path="images/tx-pagination-1.jpg" />
</Frame>

You will see the `next_page_params` object. Add the parameters from this object to your next query to receive the next 50 results.

[**https://api.blockscout.com/10/api/v2/transactions?apikey=proapi\_xxxxxx\&block\_number=148445196\&index=59\&items\_count=50**](https://api.blockscout.com/10/api/v2/transactions?apikey=proapi_xxxxxx\&block_number=148445196\&index=59\&items_count=50)

Repeat this process to continue receiving results in groups of 50 (remove params and substitute the new `next_page_params` found in the body of the query).

<Frame>
  <img src="https://mintcdn.com/blockscout/hSpk2S3pm3N4c9cZ/images/tx-pagination-2.jpg?fit=max&auto=format&n=hSpk2S3pm3N4c9cZ&q=85&s=2afa1e44bc9f04729368663f0a2effdc" alt="Tx Pagination 2" width="1522" height="1050" data-path="images/tx-pagination-2.jpg" />
</Frame>

In this example, the query to receive the next 50 results would be:

[**https://api.blockscout.com/10/api/v2/transactions?apikey=proapi\_xxxxxx\&block\_number=148445366\&index=24\&items\_count=50**](https://api.blockscout.com/10/api/v2/transactions?apikey=proapi_xxxxxx\&block_number=148445366\&index=24\&items_count=50)

# Blockscout Credit Costs

Credit amounts vary based on resource usage for different calls. The number of credits required for different calls is subject to change based on current analytics and resource usage.

You can check your credits, top calls and overall usage in the dev portal dashboard at [https://dev.blockscout.com/](https://dev.blockscout.com/)

Credits are consumed per API call. The **default cost is 20 credits** for any endpoint not listed below.

| Endpoint                                               | Credits |
| :----------------------------------------------------- | :-----: |
| `default` (all unlisted endpoints)                     |    20   |
| `api/v2/search/quick`                                  |    25   |
| `api/v2/transactions/:hash/logs`                       |    30   |
| `api/v2/transactions/:hash/token-transfers`            |    30   |
| `api/v2/transactions/:hash/state-changes`              |    30   |
| `api/v2/tokens`                                        |    30   |
| `api/v2/tokens/:address_hash/transfers`                |    30   |
| `api/v2/addresses/:address_hash/token-transfers`       |    30   |
| `api/v2/addresses/:address_hash/logs`                  |    30   |
| `api/v2/transactions/:hash/internal-transactions`      |    40   |
| `api/v2/addresses/:address_hash/internal-transactions` |    40   |
| `api/v2/smart-contracts/verification/config`           |    40   |
| `api/v2/transactions/:hash/summary`                    |    50   |
| `api/v2/transactions/:hash/raw-trace`                  |    50   |
| `api/v2/addresses/:address_hash/coin-balance-history`  |    50   |
|                                                        |         |

*Last Updated February, 2026*