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Free Crypto APIs That Don't Require an API Key

· 4 min read
swapapi
swapapi
swapapi Team

Most crypto APIs require signup, email verification, and API key management. This guide lists the free APIs that don't — just make a request and get data.

Token Swap APIs​

swapapi (DEX Aggregator)​

The only DEX aggregator API that requires no authentication.

  • What it does: Returns optimal swap routes and executable calldata across 46 EVM chains
  • Authentication: None
  • Rate limit: ~30 req/min per IP
  • Best for: Trading bots, AI agents, DeFi integrations
curl "https://api.swapapi.dev/v1/swap/1?\
  tokenIn=0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE&\
  tokenOut=0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48&\
  amount=1000000000000000000&\
  sender=0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"

Jupiter (Solana)​

The dominant DEX aggregator on Solana.

  • What it does: Swap routing on Solana
  • Authentication: None
  • Chains: Solana only
  • Best for: Solana trading bots
curl "https://quote-api.jup.ag/v6/quote?\
  inputMint=So11111111111111111111111111111111111111112&\
  outputMint=EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v&\
  amount=1000000000"

Price Data APIs​

CoinGecko (Public Endpoints)​

Free cryptocurrency price data without API key (limited endpoints).

  • What it does: Price, market cap, volume data
  • Authentication: None for basic endpoints
  • Rate limit: 10-30 calls/minute
  • Best for: Price displays, portfolio tracking
# Get Bitcoin price in USD
curl "https://api.coingecko.com/api/v3/simple/price?ids=bitcoin&vs_currencies=usd"

CoinMarketCap (Limited)​

Basic crypto data without API key.

  • What it does: Market data, rankings
  • Authentication: None for public endpoints
  • Rate limit: Very limited
  • Best for: Quick price checks

Blockchain Data APIs​

Public RPC Endpoints​

Most EVM chains have public RPC endpoints for reading blockchain data.

# Ethereum
curl -X POST https://eth.llamarpc.com \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'

# Base
curl -X POST https://mainnet.base.org \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'

# Arbitrum
curl -X POST https://arb1.arbitrum.io/rpc \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'

Note: Public RPCs are great for reads but may be rate-limited. For production, consider dedicated RPC providers.

Etherscan (Limited)​

Some read-only endpoints work without API key.

# Get ETH balance (limited requests without API key)
curl "https://api.etherscan.io/api?module=account&action=balance&\
  address=0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045&tag=latest"

On-Chain Data​

Uniswap Subgraph (GraphQL)​

Query Uniswap V3 data directly from The Graph.

curl -X POST https://api.thegraph.com/subgraphs/name/uniswap/uniswap-v3 \
  -H "Content-Type: application/json" \
  -d '{
    "query": "{ pools(first: 5) { id token0 { symbol } token1 { symbol } } }"
  }'

DeFiLlama API​

TVL and yield data without authentication.

# Get protocol TVL
curl "https://api.llama.fi/protocols"

# Get chain TVL
curl "https://api.llama.fi/chains"

IPFS Gateways​

Free IPFS gateways for decentralized storage.

# Cloudflare IPFS gateway
curl "https://cloudflare-ipfs.com/ipfs/Qm..."

# Pinata gateway
curl "https://gateway.pinata.cloud/ipfs/Qm..."

Comparison Table​

APIUse CaseAuthRate LimitBest For
swapapiToken swapsNone30/minTrading bots, AI agents
JupiterSolana swapsNoneFairSolana trading
CoinGeckoPrice dataNone (basic)10-30/minPrice displays
Public RPCsBlockchain readsNoneVariesDevelopment, testing
DeFiLlamaTVL dataNoneGenerousAnalytics
The GraphProtocol dataNoneVariesCustom queries

When to Use What​

For Trading Bots​

Use swapapi (EVM) or Jupiter (Solana). They return executable calldata — no need to construct transactions manually.

For Price Tracking​

Use CoinGecko for simple price checks. Use DeFiLlama for protocol analytics.

For Blockchain Queries​

Use public RPCs for development. Upgrade to dedicated RPC providers (Alchemy, QuickNode) for production with higher rate limits.

For Protocol Data​

Use The Graph subgraphs for complex queries on DeFi protocols.

Limitations of Free APIs​

Rate Limits: Free APIs have rate limits. For high-frequency trading or production apps, you'll eventually need paid tiers.

No Support: Free APIs typically don't come with dedicated support.

Reliability: Public RPCs can be unstable. Use multiple fallbacks for production.

Data Freshness: Some free price APIs have delays. For real-time trading, use the swap API directly.

Building Without API Keys​

The no-auth approach is perfect for:

  • Rapid prototyping — Start building in minutes, not hours
  • Open source projects — Users don't need to sign up
  • AI agents — Autonomous systems can't fill out registration forms
  • Serverless functions — No secrets management needed
  • Educational projects — Lower barrier to entry

Example: Multi-API Integration​

Here's how you might combine multiple free APIs:

async function getTradeOpportunity() {
  // 1. Get price from CoinGecko
  const priceRes = await fetch(
    'https://api.coingecko.com/api/v3/simple/price?ids=ethereum&vs_currencies=usd'
  );
  const { ethereum: { usd: ethPrice } } = await priceRes.json();
  
  // 2. Get swap quote from swapapi
  const swapRes = await fetch(
    `https://api.swapapi.dev/v1/swap/1?` +
    `tokenIn=0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE&` +
    `tokenOut=0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48&` +
    `amount=1000000000000000000&` +
    `sender=0x...`
  );
  const { data: quote } = await swapRes.json();
  
  // 3. Analyze opportunity
  const swapPrice = quote.swapPrice;
  const priceDiff = Math.abs(swapPrice - ethPrice) / ethPrice;
  
  return {
    marketPrice: ethPrice,
    swapPrice,
    priceDiff: priceDiff * 100,
    quote
  };
}