What is an agent wallet on Hyperliquid?
An agent wallet, which Hyperliquid also calls an API wallet, is a separate key your main wallet approves to sign orders for it. It can place and cancel orders on your account, but it cannot withdraw or send funds to anyone else. Approval is a signature, not a transaction. An account can have up to four, and each approval lasts at most 180 days.
- An agent wallet, or API wallet, is a separate key that signs actions for your main account. Your funds stay in the main account.
- It can place and cancel orders. It cannot withdraw, and it cannot send funds to another address; at most it moves them between the account’s own balances.
- Your main wallet approves it with a signature, and the approval lasts at most 180 days.
- Each account can have one unnamed and up to three named API wallets, plus two named ones per subaccount.
- An API wallet stops working when it expires, is replaced or removed, or when the account that approved it has no funds.
What an agent wallet is
Every action on Hyperliquid, from placing an order to withdrawing, is signed by a key. An agent wallet, which Hyperliquid’s documents call an API wallet, is a second key that your main wallet authorises to sign some of those actions for it. It is used only to sign: the orders it signs trade your main account, or one of its sub-accounts.
That separation is the point. Software that trades for you, a bot or an app, needs a key it can use at any hour. An API wallet gives it one without handing over the key that controls your money.
What it can and cannot sign
An API wallet can place, change and cancel orders, and so open and close positions, on the account that approved it. It cannot withdraw, and it cannot send funds to another address. The one transfer it may sign moves funds between the account’s own balances, such as perps and spot, and Hyperliquid requires its destination to be the same address it came from.
So the worst an API wallet in the wrong hands can do is trade the account: open positions, close them and run up fees. That is still real harm, which is why it deserves the same care as any key.
- Main wallet approvesOne signature, not a transaction, naming the API wallet.
- API wallet signsOrders and cancels, at any hour, for the main account.
- Hyperliquid checksEach action must come from a key the account approved.
- Funds stay putWithdrawals and sends to anyone else still need the main wallet.
Approval and expiry
The main wallet approves an API wallet by signing an approval that names its address and, if you like, a name for it. The approval lasts at most 180 days: one approved on 25 Oct 2026 lasts until 23 Apr 2027 at the latest.
An API wallet is removed, or pruned, when the account deregisters it, when a new approval with the same name replaces it (or a new unnamed one replaces the unnamed one), when it expires, or when the account that approved it has no funds left.
Hyperliquid advises against approving an old API wallet’s address again once it has been pruned, and suggests a separate API wallet for each trading process.
How many an account can have
Each account can approve one unnamed API wallet and up to three named ones. Each subaccount can have two more named ones of its own. An API wallet can sign for the main account or for any of its sub-accounts.
Every signed action also carries a nonce, a number that puts actions in order. Hyperliquid keeps the 100 highest nonces for each signing address and accepts a new one only within a window from two days before to one day after the current time. Two programs sharing one API wallet can trip over each other’s numbers, which is another reason Hyperliquid suggests one per process.
On Hyperliquid
API wallets are created and approved on Hyperliquid itself, signed with your main wallet. Removing one, or approving a new one under the same name, ends the old one at once. An expired API wallet can no longer sign, so anything relying on it stops until a new one is approved.
In BuildTrade™, Settings › Connections walks through creating an API wallet on Hyperliquid and pasting it with your wallet address. The app checks they belong together, and the last step shows the date the authorisation expires, so a fresh one can be created before then.
One approval, in numbers
Example numbersAn API wallet approved on 25 Oct 2026 for the longest time Hyperliquid allows, and the limits that apply to every account.
- Approved on
- 25 Oct 2026
- Longest approval, in days
- 180
- Expires on
- 23 Apr 2027
- Unnamed per account
- 1
- Named per account
- 3
- Extra named per subaccount
- 2
- Withdrawals it can sign
- 0
After 23 Apr 2027 this API wallet can no longer sign, and anything that trades through it stops until a new one is approved.
Mistakes that cost traders money
- Pasting the main wallet’s key into an app.
The main wallet’s key can withdraw everything. An app that trades for you needs an API wallet, which cannot.
- Treating an API wallet as harmless.
It cannot withdraw, but it can trade the account. In the wrong hands that is still enough to lose money.
- Forgetting the expiry.
An approval lasts at most 180 days. When it ends, a bot relying on it can no longer place or cancel orders.
- Sharing one API wallet between programs.
Hyperliquid suggests one per trading process, partly because each signed action carries a number the two programs can collide on.
- Approving an old address again.
Once an API wallet has been removed or has expired, Hyperliquid advises creating a new one rather than reusing the old address.
Try it in BuildTrade™
Open Settings › Connections and pick Testnet. The steps show where the API wallet is created and what the app checks, with no real funds involved.
Exchange endpoint, Hyperliquid Docs (read October 20, 2026).
Nonces and API wallets, Hyperliquid Docs (read October 20, 2026).
BuildTrade™ is independent of, and not endorsed by, Hyperliquid.