Quickstart

Get started with the SUBFROST API in just a few minutes.

Prerequisites

• A SUBFROST account (sign up at api.subfrost.io).
• An API key from your dashboard.
• Basic familiarity with JSON-RPC.

Getting started

1. Sign up. Create an account at api.subfrost.io.
2. Verify email. Confirm your email address.
3. Create API key. Generate your first API key from your dashboard.
4. Start building. Make your first API request using the examples below.

Networks

Choose the network for your application:

• Mainnet: https://mainnet.subfrost.io
• Signet: https://signet.subfrost.io
• Regtest: https://regtest.subfrost.io

Making your first request

Using cURL

curl -X POST https://mainnet.subfrost.io/v4/jsonrpc \
  -H "Content-Type: application/json" \
  -H "x-subfrost-api-key: YOUR_API_KEY" \
  -d '{
    "jsonrpc": "2.0",
    "method": "btc_getblockcount",
    "params": [],
    "id": 1
  }'

Using JavaScript

const response = await fetch('https://mainnet.subfrost.io/v4/jsonrpc', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'x-subfrost-api-key': 'YOUR_API_KEY'
  },
  body: JSON.stringify({
    jsonrpc: '2.0',
    method: 'btc_getblockcount',
    params: [],
    id: 1
  })
});

const data = await response.json();
console.log('Block height:', data.result);

Using Python

import requests

response = requests.post(
    'https://mainnet.subfrost.io/v4/jsonrpc',
    headers={
        'Content-Type': 'application/json',
        'x-subfrost-api-key': 'YOUR_API_KEY'
    },
    json={
        'jsonrpc': '2.0',
        'method': 'btc_getblockcount',
        'params': [],
        'id': 1
    }
)

data = response.json()
print(f"Block height: {data['result']}")

Common operations

A few methods to try next. See the JSON-RPC Reference for full details.

Goal	Method	Reference
Get a Bitcoin block height	btc_getblockcount	Bitcoin Core RPC
Get a block hash by height	btc_getblockhash	Bitcoin Core RPC
Get all UTXOs for an address	esplora_address::utxo	esplora_* Methods
Get current fee estimates	esplora_fee-estimates	esplora_* Methods
Get inscription details	ord_inscription	ord_* Methods
Get rune information	ord_rune	ord_* Methods
Run a custom server-side script	lua_evalscript	Lua Scripting

Error handling

The API returns standard JSON-RPC error responses:

{
  "jsonrpc": "2.0",
  "error": {
    "code": -32601,
    "message": "Method not found"
  },
  "id": 1
}

Common error codes:

• -32700: Parse error (invalid JSON)
• -32600: Invalid request (malformed JSON-RPC)
• -32601: Method not found
• -32602: Invalid params
• -32603: Internal error

Next steps

• Authentication: set up API keys and CORS.
• JSON-RPC Reference: full method documentation.
• Lua Scripting: custom server-side scripts.