# ChainCheckAPI Introduction A REST API for validating cryptocurrency addresses across 100+ blockchain networks. **Base URL**: `https://api.chaincheckapi.com` ## Quick Start ```bash # Validate an Ethereum address (no authentication required) curl -X POST https://api.chaincheckapi.com/v1/validate \ -H "Content-Type: application/json" \ -d '{"chain": "ETH", "address": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"}' ``` **Response:** ```json { "chain": "ETH", "address": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045", "valid": true, "usage_left": "Limited by IP (30/hr)" } ``` ## Rate Limits

Tier	Requests/Hour	Authentication
Free	30	None (IP-based)
Premium	1,000	API Key required

To upgrade to Premium, [buy the membership on Patreon](https://www.patreon.com/15413123/join). # API Endpoints ## 1. Validate Address Validates if a cryptocurrency address is correctly formatted for the specified blockchain. **Endpoint:** `POST /v1/validate` **Headers:** ``` Content-Type: application/json x-api-key: your_api_key_here (optional, for Premium tier) ``` **Request Body:** ```json { "chain": "BTC", "address": "1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa" } ```

Parameter	Type	Required	Description
`chain`	string	Yes	Cryptocurrency ticker symbol (e.g., ETH, BTC, SOL)
`address`	string	Yes	Address to validate

**Success Response (200):** ```json { "chain": "BTC", "address": "1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa", "valid": true, "usage_left": 29 } ``` **Error Responses:**

Status	Error	Meaning
400	`Invalid input: 'chain' and 'address' must be strings`	Missing or invalid parameters
400	`Unsupported chain: XYZ`	Chain not supported
403	`Invalid or inactive API key`	Invalid Premium key
429	`Free tier limit exceeded (30/hr)`	Rate limit reached
429	`Hourly rate limit exceeded`	Premium tier limit reached

--- ## 2. List Supported Chains Returns all supported cryptocurrency ticker symbols. **Endpoint:** `GET /v1/chains` **Headers:** None required **Success Response (200):** ```json { "object": "list", "count": 124, "data": [ "1INCH", "ADA", "AAVE", "ALGO", "APE", "ARB", "AVAX", "BCH", "BNB", "BTC", "DOGE", "DOT", "ETH", "LTC", "MATIC", "SOL", "TRX", "USDC", "USDT", "XRP", ... ] } ``` --- ## 3. Check Usage Returns your current request usage and remaining quota. **Endpoint:** `GET /v1/usage` **Headers:** ``` x-api-key: your_api_key_here (optional) ``` **Success Response (200):** *Free Tier (no API key):* ```json { "plan": "free_public", "limit": "30/hour", "message": "You are using the free public tier via IP address." } ``` *Premium Tier (with API key):* ```json { "plan": "premium", "usage": 42, "limit": 1000, "period": "Hourly" } ``` # Supported Cryptocurrencies The API supports **124 different cryptocurrencies** across multiple blockchain families: ### Popular Chains - **Bitcoin**: BTC, BCH, LTC, DOGE, DASH - **Ethereum & EVM**: ETH, BSC, MATIC, AVAX, ARB, OP, FTM - **Layer 1s**: SOL, ADA, DOT, TRX, XRP, XLM, XMR, ATOM, NEO, EOS - **Stablecoins**: USDT, USDC, DAI, BUSD, TUSD - **DeFi Tokens**: UNI, AAVE, LINK, CRV, COMP, MKR, SNX ### Full List by Category

EVM-Compatible (Ethereum Format: 0x...)

**Layer 1 & Layer 2 Networks:** - ETH (Ethereum) - BSC, BNB (Binance Smart Chain) - MATIC, POLYGON (Polygon) - AVAX, AVALANCHE (Avalanche) - ARB, ARBITRUM (Arbitrum) - OP, OPTIMISM (Optimism) - FTM, FANTOM (Fantom) - CRO (Cronos) - ETC (Ethereum Classic) **ERC-20 Tokens:** - **Stablecoins**: USDT, USDC, DAI, BUSD, TUSD, PAX, PYUSD - **DeFi**: AAVE, UNI, LINK, CRV, COMP, MKR, SNX, YFI, 1INCH, GRT, LDO - **Memecoins**: SHIB, PEPE - **Gaming/NFT**: SAND, MANA, APE, AXS, ENJ, CHZ, ILV - **Infrastructure**: QNT, IMX, INJ, OCEAN, SKL, STORJ - **Others**: BAT, ZRX, BAND, FET, MASK, NMR, OMG, REP, WBTC And 60+ more ERC-20 tokens

Bitcoin Family

- **BTC** (Bitcoin): 1..., 3..., bc1... - **LTC** (Litecoin): L..., M..., ltc1... - **DOGE** (Dogecoin): D... - **BCH** (Bitcoin Cash): q..., p..., bitcoincash:... - **DASH**: X... - **ZEC** (Zcash): t1..., z... - **BTG** (Bitcoin Gold) - **BSV** (Bitcoin SV) - **BTCP** (Bitcoin Private) - **DGB** (DigiByte) - **RVN** (Ravencoin) - **VTC** (Vertcoin) - **NMC** (Namecoin) - **PPC** (Peercoin) - **KMD** (Komodo) - **QTUM** - **PIVX** - **ZCL** (ZClassic) - **ZEN** (ZenCash) - **HUSH**

Other Layer 1 Blockchains

- **SOL** (Solana): Base58, 32-44 chars - **BONK** (Solana token) - **TRX** (Tron): T... - **XRP** (Ripple): r... - **XLM** (Stellar): G... - **ADA** (Cardano): addr1..., D..., A... - **DOT** (Polkadot): 1... - **XMR** (Monero): 4..., 8... - **ALGO** (Algorand): Base32 - **NEO**, **GAS**: A... - **XTZ** (Tezos): tz1..., tz2..., tz3... - **EOS**: 12 chars (a-z, 1-5) - **NANO**: nano_... - **WAVES**: 3P... - **SC** (Siacoin): Hex - **LBC** (LBRY): b...

# Common Use Cases ### Wallet Integration Validate user-entered addresses before sending transactions: ```javascript async function validateBeforeSend(chain, address) { const response = await fetch('https://api.chaincheckapi.com/v1/validate', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ chain, address }) }); const result = await response.json(); if (!result.valid) { alert('Invalid address! Please check and try again.'); return false; } return true; } ``` ### Exchange/Platform Validate deposit addresses before crediting accounts: ```python def verify_deposit_address(chain, address): response = requests.post( 'https://api.chaincheckapi.com/v1/validate', json={'chain': chain, 'address': address}, headers={'x-api-key': PREMIUM_KEY} ) data = response.json() return data.get('valid', False) ``` ### Form Validation Real-time address validation in web forms: ```javascript document.getElementById('addressInput').addEventListener('blur', async (e) => { const address = e.target.value; const chain = document.getElementById('chainSelect').value; const res = await fetch('https://api.chaincheckapi.com/v1/validate', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ chain, address }) }); const result = await res.json(); if (result.valid) { e.target.classList.add('valid'); e.target.classList.remove('invalid'); } else { e.target.classList.add('invalid'); e.target.classList.remove('valid'); } }); ``` # FAQ **Q: Do I need an API key?** A: No. The free tier allows 30 requests/hour per IP without authentication. For higher limits (1,000/hr), contact us for a Premium key. **Q: What happens if I exceed the rate limit?** A: You'll receive a `429 Too Many Requests` error. Free tier resets hourly. Premium tier also resets every hour. **Q: How accurate is the validation?** A: The API uses regex pattern matching to verify address format. It does NOT check if the address exists on-chain or has funds. **Q: Can I validate multiple addresses at once?** A: No, the API validates one address per request. For bulk validation, loop through your addresses programmatically. **Q: Which chains are supported?** A: 124+ chains. Use `GET /v1/chains` to get the current list. **Q: Does this validate smart contract addresses?** A: For EVM chains, yes - smart contract addresses follow the same format as EOA (externally owned accounts). **Q: What's the difference between BTC legacy, P2SH, and Bech32?** A: All are valid Bitcoin address types. The API accepts: - Legacy (P2PKH): Starts with `1` - P2SH: Starts with `3` - Bech32 (SegWit): Starts with `bc1` **Q: How do I get a Premium API key?** A: [Buy the premium membership on Patreon](https://www.patreon.com/15413123/join). --- ## Support For Premium API keys, issues, or questions: - **Email**: support@chaincheckapi.com - **Documentation**: `/openapi.json` for OpenAPI spec **Last Updated**: January 2026 **API Version**: 1.0.0