> ## Documentation Index
> Fetch the complete documentation index at: https://docs.kuru.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Create subaccount

> Submit account_core.create_subaccount_by_sig through the opt-in Relay operational path.

Submits `account_core.create_subaccount_by_sig` when this method is enabled for the selected deployment. This is a **slow operational method**, not the low-latency trading path. Relay validates the typed request and signature where applicable, simulates the exact call against `latest`, and only then queues a sponsored transaction. See [Operational methods](/api/relay/operational) for availability, gas, and latency rules.

<Info>The example uses testnet WETH/USDC where a market is required, but all identities, nonces, timestamps, hashes, and signatures are illustrative. Read current state and build a fresh valid signature for the selected network. Omit `authorization7702` and `makerSlotsPrimed`; complete delegation first.</Info>

<ParamField body="requestId" type="string" required>New lowercase UUIDv7 for request correlation.</ParamField>
<ParamField body="method" type="string" required default="account_core.create_subaccount_by_sig">Must be `account_core.create_subaccount_by_sig`.</ParamField>
<ParamField body="wallet" type="string" required>Trading wallet matching the bearer JWT; for AccountCore operations this is the sponsoring frontend identity, not necessarily the signed authorizer.</ParamField>
<ParamField body="payload" type="object" required>Method-specific payload shown below; unknown fields are rejected.</ParamField>

The root owner or an authorized ADMIN/TRADE EOA signs. For an unregistered root, only the owner may bootstrap the first child. `subaccountSeq` is the **next nonzero uint16 sequence**, not an account ID. `authNonce` is the root authorization epoch read from AccountCore, not a millisecond nonce. Creation advances the sequence, not the epoch; wait for inclusion and read the next sequence before signing another. The trading wallet's JWT is independent of the authorizer/root owner.

Sign the exact EIP-712 type below using the `KuruAccountCore` version `1`, with the configured AccountCore proxy as `verifyingContract` and the selected chain ID (`143` mainnet; `10143` testnet):

```text theme={null}
CreateSubaccount(address rootOwner,address authorizer,uint16 subaccountSeq,uint256 authNonce,uint256 deadline)
```

<RequestExample>
  ```curl cURL theme={null}
  curl --request POST --url https://relay.testnet.kuru.io/relay \
    --header "Authorization: Bearer $KURU_RELAY_JWT" \
    --header 'Content-Type: application/json' \
    --data '{"requestId":"018f5ef2-88a1-7b41-a826-4b679010f87f","method":"account_core.create_subaccount_by_sig","wallet":"0x1111111111111111111111111111111111111111","payload":{"rootOwner":"0x3333333333333333333333333333333333333333","authorizer":"0x3333333333333333333333333333333333333333","subaccountSeq":"2","authNonce":"1","deadline":"1792500000","signature":"0x..."}}'
  ```
</RequestExample>

<ResponseExample>
  ```json BROADCAST theme={null}
  {"requestId":"018f5ef2-88a1-7b41-a826-4b679010f87f","status":"BROADCAST","txHash":"0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa","sponsorAddress":"0xbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb","sponsorNonce":"42","transactionType":"DYNAMIC_FEE"}
  ```
</ResponseExample>

`BROADCAST` means scheduling for asynchronous RPC broadcast, not provider acceptance or successful execution. Check the receipt and expected events/state. A failed estimate returns an immediate error with no transaction signed or broadcast.


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