> ## Documentation Index
> Fetch the complete documentation index at: https://chainstack-docs-polygon-erigon-trace-deprecation.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# Finalize EVM contract | Hyperliquid exchange
> Finalize the link between a HyperCore token and its HyperEVM contract. On Hyperliquid exchange.
You can only use this endpoint on the official Hyperliquid public API. It is not available through Chainstack, as the open-source node implementation does not support it yet. See [Hyperliquid methods](/docs/hyperliquid-methods) for the full availability breakdown.
This endpoint requires signature authentication. See our comprehensive [Authentication via Signatures guide](/docs/hyperliquid-authentication-guide) for implementation details.
The `finalizeEvmContract` action finalizes the link between a HyperCore token and its HyperEVM contract, using a verification method that matches how the contract was deployed.
## Parameters
### Required parameters
* `action` (object, required) — The finalize-EVM-contract action:
* `type` (string) — Must be `"finalizeEvmContract"`.
* `token` (number) — The token identifier to link.
* `input` — The verification method, one of:
* `{ "create": { "nonce": } }` — for a contract deployed from an EOA; uses the EVM deployment nonce.
* `"firstStorageSlot"` — the finalizer address is stored at the contract's first storage slot.
* `"customStorageSlot"` — the finalizer address is stored at slot `keccak256("HyperCore deployer")`.
* `nonce` (number, required) — Current timestamp in milliseconds.
* `signature` (object, required) — EIP-712 signature of the action.
### Optional parameters
* `expiresAfter` (number, optional) — Timestamp in milliseconds after which the request is rejected.
## Returns
Returns an object with the action status:
* `status` — `"ok"` if the request was processed.
* `response` — Contains operation details, with `type` `"default"`.
## Example request
```shell cURL theme={null}
curl -X POST https://api.hyperliquid.xyz/exchange \
-H "Content-Type: application/json" \
-d '{
"action": {"type": "finalizeEvmContract", "token": 0, "input": "firstStorageSlot"},
"nonce": 1234567890123,
"signature": {...}
}'
```
```python Python (hyperliquid-python-sdk) theme={null}
# Note: the official hyperliquid-python-sdk does not expose a finalizeEvmContract
# helper yet, so build and post the signed action directly.
from hyperliquid.exchange import Exchange
from hyperliquid.utils import constants
from hyperliquid.utils.signing import sign_l1_action, get_timestamp_ms
import eth_account
# Public Hyperliquid mainnet endpoint
wallet = eth_account.Account.from_key("0x...") # your private key
exchange = Exchange(wallet, constants.MAINNET_API_URL)
timestamp = get_timestamp_ms()
action = {
"type": "finalizeEvmContract",
"token": 0,
"input": "firstStorageSlot", # or "customStorageSlot", or {"create": {"nonce": 0}}
}
signature = sign_l1_action(
wallet,
action,
None, # vault_address
timestamp,
None, # expires_after
exchange.base_url == constants.MAINNET_API_URL,
)
result = exchange._post_action(action, signature, timestamp)
print(result)
```
```typescript TypeScript (@nktkas/hyperliquid) theme={null}
import { ExchangeClient, HttpTransport } from "@nktkas/hyperliquid";
import { privateKeyToAccount } from "viem/accounts";
// Public Hyperliquid mainnet endpoint (default transport)
const wallet = privateKeyToAccount("0x..."); // viem or ethers account
const transport = new HttpTransport();
const exchange = new ExchangeClient({ transport, wallet });
const result = await exchange.finalizeEvmContract({
token: 0,
input: "firstStorageSlot", // or "customStorageSlot", or { create: { nonce: 0 } }
});
console.log(result);
```
## Response example
```json theme={null}
{
"status": "ok",
"response": {
"type": "default"
}
}
```
## Use cases
* **Link a token to its EVM contract** — Complete HyperCore/HyperEVM token linkage
* **Token deployment tooling** — Finalize contracts as part of a deploy pipeline
* **Verify deployment ownership** — Prove control via deploy nonce or storage slot
## OpenAPI
````yaml openapi/hyperliquid_node_api/hypercore_exchange/exchange_finalize_evm_contract.json post /exchange
openapi: 3.0.0
info:
title: Hyperliquid Exchange API
version: 1.0.0
description: >-
API for trading operations on Hyperliquid exchange requiring authentication.
⚠️ WARNING: These endpoints require EIP-712 signatures for authentication.
The example values provided will NOT work without proper cryptographic
signing. You must implement EIP-712 signing to use these endpoints
successfully.
servers:
- url: https://api.hyperliquid.xyz
security: []
paths:
/exchange:
post:
tags:
- hyperliquid exchange
summary: Finalize EVM contract linkage
operationId: finalizeEvmContract
requestBody:
required: true
content:
application/json:
schema:
type: object
properties:
action:
type: object
properties:
type:
type: string
default: finalizeEvmContract
enum:
- finalizeEvmContract
description: Action type
token:
type: integer
description: Token identifier to link
input:
description: >-
Verification method matching how the EVM contract was
deployed. Either an object { "create": { "nonce":
} } for an EOA-deployed contract, or one
of the string literals "firstStorageSlot" or
"customStorageSlot".
oneOf:
- type: object
properties:
create:
type: object
properties:
nonce:
type: integer
description: Nonce used to deploy the EVM contract
required:
- nonce
required:
- create
- type: string
enum:
- firstStorageSlot
- customStorageSlot
required:
- type
- token
- input
nonce:
type: integer
description: Current timestamp in milliseconds
signature:
type: object
description: EIP-712 signature of the action with r, s, v components
properties:
r:
type: string
example: >-
0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef
s:
type: string
example: >-
0xfedcba0987654321fedcba0987654321fedcba0987654321fedcba0987654321
v:
type: integer
example: 27
required:
- r
- s
- v
expiresAfter:
type: integer
description: >-
Timestamp in milliseconds after which the request is
rejected (optional)
required:
- action
- nonce
- signature
example:
action:
type: finalizeEvmContract
token: 0
input: firstStorageSlot
nonce: 1705234567890
signature:
r: >-
0x1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef
s: >-
0xfedcba0987654321fedcba0987654321fedcba0987654321fedcba0987654321
v: 27
responses:
'200':
description: Finalize EVM contract result
content:
application/json:
schema:
type: object
properties:
status:
type: string
description: Request status
response:
type: object
properties:
type:
type: string
default: default
example:
status: ok
response:
type: default
````