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Official Arc Explorer | Arc Scanner by Blockscout

Andrew G

• 5 min read
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Official Arc Explorer | Arc Scanner by Blockscout

Arc mainnet is live, and Blockscout is its official block explorer, powering the chain from day one. Arc is an open, EVM-compatible Layer-1 built for the world's financial markets. This means real-time money movement, agentic optimizations, and stablecoins for gas fees starting with USDC.

Blockscout provides the transparency layer for all of it: transactions, addresses, contracts, and gas, tracked in real time at explorer.arc.io.

Arc scan via the Blockscout UI

Head to explorer.arc.io and you can:

  • Watch blocks land in real time. The home page streams new blocks as they're produced, with gas used, transaction count, and block time at a glance, useful for confirming Arc's sub-second finality.
  • Look up any address. Balances, transaction history, and token holdings for any account or contract, no key required.
  • Human readable summaries. Every transaction includes a human-readable description of what occurred.
  • Scan verified contract source. Any contract verified on Arc shows its full source code, ABI, and compiler settings on the Contract tab, with a green verification check.
  • Decode transactions and logs. For verified contracts, method calls and event logs show up decoded and human-readable instead of raw hex, so you can see exactly what a transaction did.
  • Track token transfers. ERC-20, ERC-721, and other token activity for any address or contract, with transfer history and holder counts.
  • Universal Search. One search bar for addresses, transactions, blocks, and tokens, so you rarely need to know the exact URL pattern.

Build on Arc with the Pro API

The Blockscout Pro API gives you programmatic access to everything the explorer shows, and includes the same high-throughput endpoints, API key, and account you use for 100+ Blockscout-supported EVM chains.

Step 1: Get a Pro API key

  1. Go to dev.blockscout.com and create an account.
  1. Open the Keys section and click Create API Key. Keys start with proapi_ and are shown once, so store yours safely.
  1. That's it. The free tier gives you 100K credits per day at 5 RPS. Most endpoints cost 20 credits per call, so that's roughly 5,000 requests a day for building and testing.

Once you have a key, export so the examples below work as written.

export BLOCKSCOUT_API_KEY=proapi_your_key_here

Step 2: Make your first calls

The Pro API scopes every request by chain ID. For Arc mainnet, that's 5042 in the path, and for Arc testnet it is 5042002. The same API key works on Ethereum (1) and every other supported chain (full list here)

Network stats for Arc:

curl "https://api.blockscout.com/5042/api/v2/stats?apikey=$BLOCKSCOUT_API_KEY"

Latest blocks:

curl "https://api.blockscout.com/5042/api/v2/blocks?apikey=$BLOCKSCOUT_API_KEY"

Transactions for any address:

curl "https://api.blockscout.com/5042/api/v2/addresses/0xYourAddress/transactions?apikey=$BLOCKSCOUT_API_KEY"

You can also pass the key as a header instead of a query parameter:

curl -H "authorization: Bearer $BLOCKSCOUT_API_KEY" \
  "https://api.blockscout.com/5042/api/v2/stats"

Etherscan-compatible endpoints

If you're already familiar with Etherscan's API shape, the same scan call structure works against Blockscout. Etherscan uses api.etherscan.io/v2/api?chainid=, Blockscout uses api.blockscout.com/v2/api?chain_id=:

curl "https://api.blockscout.com/v2/api?chain_id=5042&module=account&action=balance&address=0xYourAddress&apikey=$BLOCKSCOUT_API_KEY"

ETH JSON-RPC

Standard eth_ methods work through the same gateway:

curl -X POST "https://api.blockscout.com/5042/json-rpc" \
  -H "content-type: application/json" \
  -H "authorization: Bearer $BLOCKSCOUT_API_KEY" \
  -d '{"id":1,"jsonrpc":"2.0","method":"eth_blockNumber","params":[]}'

Every response includes usage headers: x-credits-remaining shows your daily balance, x-ratelimit-remaining your RPS headroom. Watch these while you build to see exactly what your app consumes.

Reading contracts and transactions

Once a contract is verified on Arc (verification runs through Blockscout, same as every other chain), its source, ABI, and metadata are queryable programmatically:

curl "https://api.blockscout.com/5042/api/v2/smart-contracts/<CONTRACT_ADDRESS>?apikey=$BLOCKSCOUT_API_KEY"

The complete decoded transaction object, status, from/to, value, gas used, fee, method, and decoded input when the contract is verified, lives at:

curl "https://api.blockscout.com/5042/api/v2/transactions/<tx_hash>?apikey=$BLOCKSCOUT_API_KEY"

Sub-endpoints follow the same pattern: /logs for decoded event logs, /token-transfers, /internal-transactions for contract-to-contract calls, /state-changes for balance diffs, and /raw-trace for the full execution trace.

The /summary endpoint runs Blockscout's transaction interpreter, returning a plain-English explanation for recognized transaction types like swaps, mints, and bridge deposits:

curl "https://api.blockscout.com/5042/api/v2/transactions/<tx_hash>/summary?apikey=$BLOCKSCOUT_API_KEY"

A note on USDC

💡
USDC is Arc's native gas token. Native-asset calls like eth_getBalance return 18-decimal values; the USDC ERC-20 interface, used for app-level transfers and display, uses the standard 6 decimals. Keep this in mind when reading values back from the API described below.

Costs and limits

Credits are consumed per call. The default is 20 credits; heavier endpoints like /transactions/:hash/summary and /transactions/:hash/raw-trace cost 50. The free tier resets 100K credits daily. When you outgrow it, the Builder plan ($49/mo) gives 100M credits at 15 RPS and the Pro plan ($199/mo) gives 500M at 30 RPS. Track live usage, top endpoints, and remaining credits in the dev portal dashboard.

Start building

Arc is a new network with familiar tooling: EVM-compatible, and Blockscout as the official explorer and data layer from day one. One Pro API key covers Arc plus every other chain Blockscout indexes.