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title Base API

Base Blockchain API with Free Access and No Cutoffs

Full block explorer API for Base developers. Free tier on all endpoints. No surprise restrictions.

Base API Access with Blockscout

Base is Coinbase's Ethereum L2 and one of the fastest-growing chains in the ecosystem. With its 2026 strategy focused on tokenized markets, stablecoin payments, and developer tooling, Base has become a magnet for consumer dapps, DeFi, SocialFi, and AI agent applications. Its TVL has grown into the multi-billion dollar range, and hundreds of teams are building across the stack.

When other API providers removed free-tier access for Base, many developers were left scrambling. Blockscout PRO API provides full API access for Base — with a free tier that isn't going anywhere.

Base Chain ID: 8453
Explorer: base.blockscout.com
PRO API Base: https://api.blockscout.com (use chain_id=8453)
API Docs: base.blockscout.com/api-docs

Quick Start

Get your first API response in under 60 seconds:

# Get ETH balance for an address on Base via PRO API
curl "https://api.blockscout.com/v2/api?chain_id=8453&module=account&action=balance&address=0xYOUR_ADDRESS&apikey=proapi_YOUR_KEY"

Get a free API key at dev.blockscout.com — required for all PRO API tiers, including free.

PRO API Routes for Base

All routes use Base's chain ID (8453):

JSON RPC v2 (Etherscan-compatible):

https://api.blockscout.com/v2/api?chain_id=8453&module=account&action=txlist&address=0x...&apikey=proapi_xxx

JSON RPC:

https://api.blockscout.com/8453/api?module=account&action=txlist&address=0x...&apikey=proapi_xxx

REST API:

https://api.blockscout.com/8453/api/v2/addresses/0x.../transactions?apikey=proapi_xxx

ETH RPC (POST):

curl -H "content-type: application/json" \
  -H "authorization: Bearer proapi_xxx" \
  -X POST \
  --data '{"id":0,"jsonrpc":"2.0","method":"eth_blockNumber","params":[]}' \
  https://api.blockscout.com/8453/json-rpc

Available Endpoints

Etherscan-Compatible Modules

All standard modules work — if you've used Etherscan's Base API before, the same parameters apply:

  • Account — Balances, transaction lists, token transfers, internal transactions, ERC-20/721/1155 activity (plus Blockscout extras: eth_get_balance, pendingtxlist, tokenbalance, tokenlist)
  • Contract — ABI, source code, verification (plus: listcontracts, getcontractcreation, Vyper & Sourcify verification)
  • Transaction — Status checks (plus: gettxinfo)
  • Logs — Event logs with filtering by address, topics, block range
  • Token — Token metadata, holders
  • Stats — Supply, chain statistics, coin price
  • Block — Block rewards, countdown, block number by time
  • Gas Tracker — Gas oracle, gas estimates

REST API

Blockscout's native REST API provides enriched metadata, decoded input data, NFT media and attributes, smart contract read/write interaction, and chain health monitoring — all accessible through the PRO API.

→ Full REST API Reference

Base API Pricing

Tier Rate Limit Credits Price
Free 5 RPS 100K/day $0
Builder 15 RPS 100M/mo $49/mo
Pro 30 RPS 500M/mo $199/mo
Business 50 RPS 3B/mo $999/mo
Enterprise Custom Custom Contact us

Every tier includes access to all 117 Blockscout-supported chains — not just Base. One API key, one account, one chain_id parameter swap to query any network.

Switching from Etherscan's Base API?

Etherscan lists Base as paid-only (⚠️). Blockscout provides free access on all tiers. Since both APIs now use a unified multichain format, the migration is a base URL and key swap:

// Before (Etherscan V2 — Base requires paid tier)
const resp = await fetch(
  `https://api.etherscan.io/v2/api?chainid=8453&module=account&action=balance&address=${addr}&apikey=${ETHERSCAN_KEY}`
);

// After (Blockscout PRO API — free tier available)
const resp = await fetch(
  `https://api.blockscout.com/v2/api?chain_id=8453&module=account&action=balance&address=${addr}&apikey=${BLOCKSCOUT_KEY}`
);

Same structure: chainid → chain_id, swap the base URL and key.

→ Full Migration Guide

What Developers Build on Base with Blockscout's API

Consumer Dapps & SocialFi — Base is home to Farcaster, Zora, and a growing SocialFi ecosystem. Blockscout's API powers transaction history, token balances, and NFT data for these applications.

DeFi Backends — With billions in TVL across DEXs, lending markets, and yield platforms, Base DeFi apps rely on explorer APIs for contract data, event monitoring, and position tracking.

AI Agents & Automation — Base's 2026 roadmap includes native support for AI agent smart accounts. Blockscout's PRO API and MCP server provide the structured onchain data these agents need.

Wallets & Portfolio Trackers — Pull complete transaction histories, multi-token balances, and NFT holdings for Base addresses through a single API key that also covers every other chain.

Base on Blockscout

As part of the OP Superchain, Base benefits from Blockscout's native support for L1↔L2 transaction tracking, including deposit and withdrawal views and cross-chain message debugging. Blockscout provides free API access for Base where Etherscan requires a paid plan — and over 84 chains run Blockscout as their exclusive explorer. With the PRO API's multichain architecture, querying Base is just one chain_id parameter away from querying Ethereum, Optimism, Arbitrum, or any other supported network.

Get Started

  1. Get a free API key at dev.blockscout.com
  2. Use chain_id=8453 in your PRO API requests
  3. Explore endpoints at base.blockscout.com/api-docs

→ Start Building on Base · → PRO API Routes Reference