> ## 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 General Info

# Blockscout PRO API — Multichain Onchain Data, One API Key

> Production-grade blockchain data across 100+ EVM chains. Familiar endpoints. Generous limits. Predictable pricing.

## The Problem

Building multichain? You're probably managing separate API keys, billing accounts, and rate limits for every chain you support. When a provider drops free-tier access or changes terms without warning, your app breaks.

Blockscout PRO API eliminates that fragmentation. One account, one API key, dozens of mainnets and testnets — with the same endpoint structure you already know.

## Why Developers Switch to Blockscout PRO API

### Multichain by Default

Access onchain data across all Blockscout-supported chains through a single API key. Add a new chain by changing a `chain_id` parameter — no new vendor setup, no duplicated integration work.

```text theme={null}
https://api.blockscout.com/v2/api?chain_id=1&module=account&action=balance&address=0x...&apikey=proapi_xxx
```

Swap `chain_id=1` for `chain_id=8453` (Base), `chain_id=10` (Optimism), `chain_id=534352` (Scroll), or any supported chain.

### What Chains are Supported?

The up-to-date list is available at [dev.blockscout.com](http://dev.blockscout.com) under supported chains.

<Accordion title="PRO API Supported Chains (last update May 2026)">
  ## Mainnets

  | Chain                     | Chain ID  |
  | ------------------------- | --------- |
  | Arbitrum Nova             | 42170     |
  | Arbitrum One Nitro        | 42161     |
  | Astar                     | 592       |
  | Awaji                     | 6497      |
  | Base                      | 8453      |
  | BXN                       | 488       |
  | Celo                      | 42220     |
  | Creditcoin                | 102030    |
  | Cross Mainnet             | 612055    |
  | Eden                      | 714       |
  | EDU Chain                 | 41923     |
  | Ethereum                  | 1         |
  | Ethereum Classic          | 61        |
  | Etherlink                 | 42793     |
  | Filecoin Virtual Machine  | 314       |
  | Flow Mainnet              | 747       |
  | Fuse                      | 122       |
  | Gensyn                    | 685689    |
  | Gnosis                    | 100       |
  | HashKey                   | 177       |
  | ICB Network               | 73115     |
  | Immutable zkEVM           | 13371     |
  | Ink                       | 57073     |
  | IOTA EVM                  | 8822      |
  | KiteAI Mainnet            | 2366      |
  | LightLink Phoenix Mainnet | 1890      |
  | Lisk                      | 1135      |
  | Matchain                  | 698       |
  | MegaETH                   | 4326      |
  | Moca Chain                | 2288      |
  | Mode                      | 34443     |
  | Neon                      | 245022934 |
  | Numine                    | 8021      |
  | OP Mainnet                | 10        |
  | Playnance Playblock       | 1829      |
</Accordion>

### Etherscan-Compatible Endpoints

Already using Etherscan V2's unified API? Migration is trivial — the structure is nearly identical. Etherscan uses `api.etherscan.io/v2/api?chainid=`, Blockscout uses `api.blockscout.com/v2/api?chain_id=`. Same modules, same parameters — swap the base URL and key.

**→ [Migration Guide: Etherscan to Blockscout](/devs/migrate-from-etherscan)**

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

### More Capacity at Every Tier

|                | Blockscout PRO API                    | Etherscan              |
| -------------- | ------------------------------------- | ---------------------- |
| **Free**       | 100K credits/day · 5 RPS · All chains | 3 RPS · Limited chains |
| **\$49/mo**    | 100M credits · 15 RPS                 | 100K calls · 5 RPS     |
| **\$199/mo**   | 500M credits · 30 RPS                 | 200K calls · 10 RPS    |
| **Enterprise** | Custom                                | Custom                 |

### Explorer-Enriched Data

PRO API serves the same indexed, decoded, and structured data that powers Blockscout explorers. That means token metadata, proxy implementations, internal transactions, and contract context — not just raw RPC responses.

## Built For

* **Dapps & Wallets** — Transaction history, token balances, NFTs, and contract activity across chains
* **AI Agents & Bots** — Structured onchain data for monitoring, automation, and AI-driven workflows
* **Analytics & Research** — Cross-chain behavior analysis, dashboards, and reporting
* **Operational Tooling** — Debugging, compliance workflows, and internal monitoring

## Get Started in 3 Steps

1. **Create an account** at [dev.blockscout.com](https://dev.blockscout.com)
2. **Generate your API key** — free tier starts immediately
3. **Query any supported chain** using familiar REST or JSON-RPC endpoints

No credit card required for the free tier. Upgrade when you're ready.

**→ [Start Building](https://dev.blockscout.com)**

## Trusted Infrastructure

Blockscout powers explorers for 100+ L2s and scaling projects. The PRO API runs on the same infrastructure and data pipeline — formalized for production workloads with higher limits, real-time usage dashboards, and up to 50 API keys per account.

**→ [View Supported Chains](https://chains.blockscout.com)** **→ [API Documentation](https://docs.blockscout.com/devs/apis)** **→ [Developer Portal](https://dev.blockscout.com)**