account_nextIndex - JSON-RPC Method

Description

Returns the next usable transaction index (nonce) for the given account. On Moonriver, accounts are H160 (Ethereum-style) by default; you may pass either a 0x H160 address or its SS58-encoded representation.

Parameters

Parameter	Type	Required	Description
accountId	string	Yes	Account identifier (H160 hex or SS58 string)

Returns

Field	Type	Description
result	number	Next transaction nonce for the account

Request Example (H160 address)

curl -s https://api-moonriver.n.dwellir.com/YOUR_API_KEY \
  -H 'Content-Type: application/json' \
  -d '{
    "jsonrpc":"2.0",
    "id":1,
    "method":"account_nextIndex",
    "params":["0x6bEc0BCA2F15876f675f2C38958Ff986551e4db1"]
  }'

Example response:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": 1347
}

Notes

• For SS58 formatting, ensure you use Moonriver’s prefix 1285 if you choose to encode the H160 into SS58 form.
• Nonce increases with each included extrinsic signed by the account.