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POST
Build an unsigned reward withdrawal transaction

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

Body

application/json
stakeAddress
string
required
Maximum string length: 256
amount
string
required
Maximum string length: 20
Pattern: ^[0-9]+$
changeAddress
string
required
Maximum string length: 256
utxos
object[]
Maximum array length: 200
senderAddress
string
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
ttl
integer<int64>

Response

Withdrawal transaction built successfully

tx_cbor
string
tx_hash
string
estimated_fee
string
estimated_signatures
integer<int32>
{key}
any