blockfrost Cardano API

Cryptocurrency / API Key Intermediate HTTPS
Varies by plan (check documentation)

Overview

Blockfrost provides a managed API layer for interacting with the Cardano blockchain without running your own node. You can query block data, transaction details, native asset metadata, staking pool information, and IPFS content through simple REST calls. It supports both Cardano mainnet and preview/preprod testnets, making it the standard choice for Cardano dApp developers.

💡

Beginner Tip

Sign up at blockfrost.io to get a free project ID (which acts as your API key) — the free tier allows 50,000 requests per day. Always include your project ID in the project_id request header, not as a query parameter.

Available Data

coin price in USD/EUR
market capitalization
24h price change
trading volume
circulating supply
vehicle make and model

Example Response

JSON Response
{
  "id": "bitcoin",
  "symbol": "btc",
  "current_price": 65432.1,
  "market_cap": 1280000000000,
  "price_change_24h": 1250.5,
  "price_change_percentage_24h": 1.95,
  "total_volume": 28500000000
}

Field Reference

hash Unique hex hash identifying this Cardano block.
height Block number in the Cardano blockchain sequence.
time Unix timestamp when this block was produced.
tx_count Number of transactions confirmed in this block.
slot Slot number within the current Cardano epoch.
epoch Epoch number this block belongs to (each epoch is approximately 5 days).

Implementation Example

const url = "https://blockfrost.io/";
// Replace headers or query params with the values required by this API.
const response = await fetch(url, {
  headers: {
  "X-API-Key": "YOUR_API_KEY"
  }
});
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(data);

What Can You Build?

Note: These code examples are AI-generated and unverified. Always refer to the official API documentation for accurate usage.

Common Errors & Troubleshooting

403 Project not found or invalid project_id The project ID in the header does not match the selected network environment.
Create separate Blockfrost projects for mainnet and testnet; a mainnet key will not work on preprod endpoints.
404 block or transaction not found Cardano uses hash strings for block and transaction IDs, which must be exact 64-character hex values.
Verify the hash by checking it on a Cardano block explorer like cardanoscan.io before using it in API calls.
402 Usage exceeded for today The free tier is capped at 50,000 calls per day.
Upgrade to a paid plan for higher limits, or implement local caching to reduce redundant API calls.

Matrix Score Breakdown

🌐 Reachability 30/30
⚡ Speed 15/20
🔒 Security 15/15
🛠 Developer XP 12/20
✓ Reliability 10/15

Partially tested on Apr 5, 2026

Technical Specifications

Auth API Key
HTTPS REQUIRED
CORS UNKNOWN
Category Cryptocurrency
Difficulty Intermediate
Verified: 2026-04-04

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