getblockhash

curl --user "$RPC_USER:$RPC_PASS" \
  --data-binary '{"jsonrpc":"1.0","id":"docs","method":"getblockhash","params":[0]}' \
  -H 'content-type: text/plain;' \
  http://127.0.0.1:8332/

bitcoin-cli getblockhash 1000

curl --user myusername --data-binary '{"jsonrpc": "2.0", "id": "curltest", "method": "getblockhash", "params": [1000]}' -H 'content-type: application/json' http://127.0.0.1:8332/

import requests
r = requests.post(
    "http://127.0.0.1:8332/",
    auth=("$RPC_USER", "$RPC_PASS"),
    json={
        "jsonrpc": "1.0",
        "id": "docs",
        "method": "getblockhash",
        "params": [0],
    },
    timeout=30,
)
print(r.json())

const res = await fetch("http://127.0.0.1:8332/", {
  method: "POST",
  headers: {
    "content-type": "application/json",
    "authorization": "Basic " + btoa(`${process.env.RPC_USER}:${process.env.RPC_PASS}`),
  },
  body: JSON.stringify({
    jsonrpc: "1.0",
    id: "docs",
    method: "getblockhash",
    params: [0],
  }),
});
console.log(await res.json());