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GET
Get Cardano era summaries for slot-to-time math

Authorizations

X-Api-Key
string
header
required

API key (programmatic access — recommended)

Send your API key in the X-Api-Key header. Keys start with nxs_ and are created in the dashboard (or via POST /api/keys with a session JWT).

Each key is scoped to one chain and one network (for example CARDANO_MAINNET), fixed at creation time. It cannot query a different network on the same chain, and it cannot query a different chain at all. A mismatched network parameter returns 400 Network Mismatch. Create one key per chain and network under the same account.

This is the credential most integrations should use.

Query Parameters

network
enum<string>

Accepts either the value listed here (CARDANO_MAINNET) or its kebab-case alias (cardano-mainnet); matching is case-insensitive. Omit it and the network is taken from the API key. A value that disagrees with the key's own network returns 400 Network Mismatch.

Available options:
CARDANO_MAINNET,
CARDANO_PREPROD,
CARDANO_PREVIEW,
APEX_PRIME_MAINNET,
APEX_VECTOR_MAINNET,
APEX_VECTOR_TESTNET,
MIDNIGHT_MAINNET,
MIDNIGHT_PREPROD,
MIDNIGHT_STAGENET,
BITCOIN_MAINNET,
BITCOIN_TESTNET4

Response

Successfully retrieved era summaries

era
integer<int32>
default:""

Era number. 1 is Byron, 2 Shelley, and so on.

Example:

2

name
string
default:""

Era name

Example:

"Shelley"

startSlot
integer<int64>
default:""

Absolute slot the era began at

Example:

4492800

startEpoch
integer<int32>
default:""

Epoch the era began at

Example:

208

slotLengthMs
integer<int32>
default:""

Slot duration inside this era, in milliseconds

Example:

1000

epochLength
integer<int32>
default:""

Slots per epoch inside this era

Example:

432000

startBlock
integer<int64>
default:""

Height of the first block of the era. Null for the synthesized Byron era.

Example:

4490511

startBlockHash
string
default:""

Hash of the first block of the era. Null for the synthesized Byron era.

Example:

"aa83acbf5904c0edfe4d79b3689d3d00fcfc553cf360fd2229b98d464c28e9de"