queryLedgerState_eraSummaries - Cardano

Example code for the queryLedgerState_eraSummaries JSON-RPC method. Complete guide on how to use queryLedgerState_eraSummaries JSON-RPC in GetBlock Web3 documentation.

This method returns summaries of all known eras, giving the parameters needed to convert between slots, epochs, and wall-clock time across hard forks.

Parameters

• None

Request

cURL

curl --location --request POST 'https://go.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{
    "jsonrpc": "2.0",
    "method": "queryLedgerState/eraSummaries",
    "id": "getblock.io"
}'

JavaScript

example.js

const response = await fetch(
    'https://go.getblock.io/<ACCESS-TOKEN>/',
    {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({"jsonrpc": "2.0", "method": "queryLedgerState/eraSummaries", "id": "getblock.io"})
    }
);
console.log(await response.json());

Python

example.py

import requests

response = requests.post(
    'https://go.getblock.io/<ACCESS-TOKEN>/',
    headers={'Content-Type': 'application/json'},
    json={"jsonrpc": "2.0", "method": "queryLedgerState/eraSummaries", "id": "getblock.io"}
)

print(response.json())

Response

{
    "jsonrpc": "2.0",
    "method": "queryLedgerState/eraSummaries",
    "result": [
        {
            "start": {
                "time": {
                    "seconds": 0
                },
                "slot": 0,
                "epoch": 0
            },
            "end": {
                "time": {
                    "seconds": 89856000
                },
                "slot": 4492800,
                "epoch": 208
            },
            "parameters": {
                "epochLength": 21600,
                "slotLength": {
                    "milliseconds": 20000
                },
                "safeZone": 4320
            }
        }
    ],
    "id": "getblock.io"
}

Response Parameters

Field	Type	Description
start	object	Bound at which the era begins
end	object	Bound at which the era ends
parameters	object	Epoch length, slot length, and safe zone for the era

Use Cases

• Time Conversion: Convert any slot to time across all eras

• Scheduling: Compute future epoch and slot boundaries

• Wallet Backends: Translate slots to dates for transaction history

• Analytics: Normalize timestamps across hard forks

Error Handling

Error Code	Message	Description
-32602	Invalid params	A required field is missing or has the wrong type
-32000	Query unavailable	The query is not available in the current ledger era
-32603	Internal error	The node failed to answer the query