Hyperliquid Signing

How do I add a Hyperliquid API key in Sandwich?

Create and authorize an agent wallet on Hyperliquid, then generate your API credentials.
Add these credentials in Sandwich, sign the builder code to authorize access, and save once the connection is verified.

Is this the same as approving a contract on MetaMask?

No. Signing = proof of identity (safe, no gas). Approving a contract = giving permission to spend tokens (not used for login).

Do I need to sign every time I log in?

Sometimes, yes. For security reasons, Hyperliquid may ask for a new signature when you reconnect or after a session timeout.

What happens if I reject the signature request?

If you reject it, you simply won’t be able to log in or perform certain actions. No harm is done.

Can Hyperliquid ever access or move my funds through message signing?

No. Message signing cannot move assets. Only approve or send transactions can move funds, and Hyperliquid does not ask for that during the sign-in process.

I keep getting an "Invalid signature" error. What should I do?

Try these fixes: disconnect and reconnect your soft wallet, clear your browser cache, ensure the wallet extension is updated, and switch networks back and forth. If the problem persists, restart your browser.

Can I use a hardware wallet?

Yes. If your Ledger or Trezor is connected through a supported wallet application, you can sign authentication messages using that device.

Why does Hyperliquid require signing instead of a password?

Signing is more secure. It proves ownership of your wallet cryptographically, eliminating weak passwords and phishing risks.

Does Hyperliquid store my private key?

No. Your private key remains inside your soft wallet. Hyperliquid only receives the signed message, not the key itself.

My wallet says “Signature request.” What does that mean?

This is normal—the soft wallet is asking you to confirm the login/auth request. Just check the message contents and click Sign if everything looks correct.

I signed the message, but nothing happened. What should I do?

Make sure your wallet is set to the correct network. Then refresh the page, reconnect, and ensure your browser isn’t blocking any pop-ups.

Is it safe to sign the message?

Yes. Message signing only verifies ownership.You are not granting spending permissions or approving smart contracts.

What exactly am I signing?

You are signing a human-readable message that proves wallet ownership. Hyperliquid does not ask you to sign anything that gives permission to move funds.

Why does my wallet pop up asking me to sign a message?

Your wallet prompts you to sign so Hyperliquid can confirm that you are the owner of the wallet. This prevents unauthorized access and protects your account.

Do I need to pay gas fees to sign?

No. The signing process is completely gas-free. You are only signing a message, not submitting a blockchain transaction.

Why do I need to sign a builder code on Hyperliquid?

Signing our builder code allows for all application fees to be replaced by the builder fees on all Hyperliquid trades. Hyperliquid requires your approval to do this.