07_node_rpc.py

# SPDX-License-Identifier: MIT
"""07 - Talk to your own node over JSON-RPC.

Set RPC_URL / RPC_USER / RPC_PASS in the environment (or config.py). For a local node
the safest auth is the auto-generated .cookie file: use its `user:pass` contents.
Keep RPC private and never expose it (see testnethub.com/rpc-safety).

    RPC_USER=... RPC_PASS=... python 07_node_rpc.py
"""
import requests
from config import RPC_URL, RPC_USER, RPC_PASS


def rpc(method, params=None):
    payload = {"jsonrpc": "1.0", "id": "ex", "method": method, "params": params or []}
    try:
        r = requests.post(RPC_URL, json=payload, auth=(RPC_USER, RPC_PASS), timeout=15)
    except requests.exceptions.RequestException:
        raise SystemExit(f"could not reach your node at {RPC_URL}. is it running with RPC "
                         "enabled? see testnethub.com/run-node")
    if r.status_code == 401:
        raise SystemExit("the node rejected the login: set RPC_USER / RPC_PASS (see testnethub.com/rpc-safety)")
    body = r.json()
    if body.get("error"):
        raise SystemExit(f"the node rejected the call: {body['error']['message']}")
    return body["result"]


info = rpc("getblockchaininfo")
print(f"chain    : {info['chain']}")
print(f"blocks   : {info['blocks']:,}")
print(f"progress : {info['verificationprogress'] * 100:.2f}%")
print(f"new addr : {rpc('getnewaddress')}")