blockfrost Cardano

Overview

Blockfrost provides a unified API for the Cardano blockchain — blocks, transactions, addresses, assets, and stake pools — so you don’t need to run a Cardano node. Auth is a free project ID (requests without one return 403, verified).

Quick Start

Latest block (replace YOUR_KEY):

curl "https://cardano-mainnet.blockfrost.io/api/v0/blocks/latest" \
  -H "project_id: YOUR_KEY"

{
  "hash": "abc123...",
  "height": 12345678,
  "slot": 123456789,
  "epoch": 456,
  "time": 1724300000
}

Address details:

curl "https://cardano-mainnet.blockfrost.io/api/v0/addresses/addr1..." \
  -H "project_id: YOUR_KEY"

Asset metadata:

curl "https://cardano-mainnet.blockfrost.io/api/v0/assets/{asset_id}" \
  -H "project_id: YOUR_KEY"

Authentication

• Register at blockfrost.io → create a project → copy the Project ID.
• Send it as the project_id header (missing → 403, verified).
• Mainnet and testnet have different hosts (cardano-mainnet, cardano-testnet).

Rate Limits & Notes

• Free tier: 50,000 requests/day (per project) — generous; paid plans scale.
• Endpoints: /blocks, /transactions, /addresses, /assets, /pools, /epochs, and more.
• Responses are JSON with pagination via page/count query params.
• Also serves other Cardano networks (preprod, preview) and a full API explorer on the dashboard.

FAQ

Is Blockfrost free? Free tier: 50,000 requests/day per project; more is paid.

How do I get a project ID? Register at blockfrost.io → create a project → copy the Project ID.

Is it only mainnet? Mainnet + testnet networks are available (different hosts).